12472301_TACOM_Welding_Aluminum_Code_(1).pdf

19207-12472301 Revision A Page 1 of 123

Revisions

LTR Description

Date(YY-MM-DD) Approved

--- Initial Release Direct ERR FOM U5152 01-08-08 T. A. Higgins

A Direct ERR FOM U8332 Incorporated ADCN 157518 03-04-30 T. A. Higgins

Acknowledgment Design Activity

U.S. Army Tank-Automotive and Armaments Command

Warren, Michigan 48397-6000

This code is based on commercial and military specifications; primarily ANSI/AWS B2.1, ANSI/AWS D1.2, MIL-STD 1946 and MIL-STD 372.

This document was prepared by a team from United Defense, L.P., Ground Systems Division (UDLP) and the U.S. Army’s Tank-Automotive Armament Research, Development and Engineering Center (TARDEC).

Design Approval T. A. Higgins

Ground Combat Vehicle Welding Code -

Aluminum Drawn Date Drawing Approval Size Cage Code

Richard J. Rush 01/03/08 Tom Altobelli A 19207 12472301

UNCLASSIFIED: Distribution Statement A. Approved for public release.

UNCLASSIFIED: Distribution Statement A. Approved for public release.

19207-12472301 Revision A Page 2 of 123

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19207-12472301 Revision A Page 3 of 123

Preface

Format This document follows the AWS format, and is based on the current practice in the manufacture of ground combat vehicles. Therefore, the section that normally would be included to establish design standards has been eliminated from this code. This follows the practice within this industry of having design performed by structural design engineers using the latest in finite element analysis techniques.

This code has been divided into 9 sections (sections 1 through 10, with section 2, normally applied to design, eliminated) that can be grouped into the following areas related to welding manufacture:

• General welding procedural requirements for the qualification of welding processes and weld joint geometries.

• Specific requirements for qualifying welders for various welding processes.

• Specific requirements for welds in four different categories:

– Stud Welding

– Non-Critical Welding

– Critical Welding (Except Ballistic Structures)

– Ballistic Welding

Generally, the requirements for welds in the latter three categories can be related to the prior military specifications, as follows:

• Quality standards of Section 8, related to welding of attachments, is based upon MIL- STD-372, Class B.

• Quality standards of Section 9, related to welding of primary nonballistic structures, is based upon MIL-STD-372, Class A.

• Quality standards of Section 10, related to welding of structures subject to ballistic attack, is based upon MIL-STD-1946.

For simplicity, this document can be divided into separate working sections. Sections 7 through 10 describe the requirements for specific weld categories and should be used to control welding of these individual categories. They should be used in conjunction with Section 6 which establishes basic quality procedures.

Sections 1 through 5, excluding the nonexistent Section 2, establish the general workmanship and technique requirements for all aluminum welding.

It also establishes the qualification of procedures and of welders. These sections produce the framework for good welding performance in any facility fabricating components for our country’s defense. They must be followed for the establishment of an acceptable facility with welders capable of performing the welding needed for this fabrication.

Specification Cross Reference A table is included on page 4 to provide a cross-reference between this code and military standards and specifications (active and cancelled).

Revisions This code and all revisions will be electronically maintained. Signed original copy of document located at AMSTA-TR-E.

Recommendations for change must be submitted in writing to U.S. Army Tank-Automotive and Armament Research, Development and Engineering Center (TARDEC), Attention AMSTA-TR-E/MEPS. Consensus of the standing Weld Team is required for revisions to this code.

TARDEC/UDLP Weld Team

Charter Members

• Michael W. Davis – UDLP

• Steven W. Taylor – UDLP

• Richard J. Rush – UDLP

• David Berridge – UDLP

• Marvin Kohn - UDLP

• Terry A. Higgins – TARDEC

• Joe B. Regmont – TARDEC

• Lucien A. Vita – TACOM/ARDEC

19207-12472301 Revision A Page 4 of 123

Table P.1

WELD SPECIFICATION CROSS REFERENCE MATRIX

Previous Specification Ground Combat Vehicle Weld Code MIL-STD-370 Grade A (SP) Section 10 (Other requirements as specified)

Grade A Section 10

Grade B Section 9

Grade C Section 8

MIL-STD-372 Class A Section 9

Class B Section 8

MIL-STD-1946 Armor to Armor Section 10

Attachments to Armor Section 8

MIL-STD-2219 All Classes Section 9

MIL-W-45205 Class A Section 9

Class B Section 8

MIL-W-45206 Armor to Armor Section 10

Attachments to Armor Section 8

MIL-STD-45211 Stud Welding Section 7

ANSI/AWS D1.2 (Nontubular) Statically Loaded Section 8

Dynamically Loaded Section 9

ANSI/AWS D1.2 (Tubular) Tubular Section 9

ANSI/AWS D1.2 No Designation Section 9

Drawing 12309000 Level 1A Section 9

Level 1C Section 10

Level 2A Section 8

Level 2C Section 10

Level 3B Section 8

Level 3C Section 8

Level 4B Section 8 (Other requirements as specified)

Level 4C Section 8 (Other requirements as specified)

Level 4D Section 7

19207-12472301 Revision A Page 5 of 123

TABLE OF CONTENTS

Preface List of Tables List of Figures

1 GENERAL PROVISIONS

1.1 Scope

1.2 Approval

1.3 Materials

1.4 Welding Processes

1.5 Equipment Calibration

1.6 Definitions

1.7 Welding Symbols

1.8 Safety Precautions

1.9 Standard Units of Measurement

3 WORKMANSHIP

3.1 General

3.2 Preparation of Base Material

3.3 Assembly

3.4 Control of Distortion and Shrinkage

3.5 Weld Profiles

3.6 Rework/Repairs

3.7 Cleaning of Completed Welds

4 TECHNIQUE

Part A General Requirements For Gas Metal Arc, Gas Tungsten Arc, Plasma Arc

(Variable Polarity) Welding

4.1 Material Requirements

4.2 Welding Processes

4.3 Shielding Gases

4.4 Preheat Requirements

4.5 Interpass Temperature Requirements

4.6 Arc Strikes

4.7 Cleaning Prior to Welding`

4.8 Weld Termination

4.9 Backing to Prevent Melting Through

4.10 Peening

4.11 Thermal Stress-Relief Treatment

Part B Gas Metal Arc Welding

4.12 General

4.13 Restrictions on Gas Metal Arc Welding With Single Electrode

Part C General Requirements Gas Tungsten Arc Welding

4.14 General

4.15 Tungsten Electrodes

4.16 Restrictions on Gas Tungsten Arc Welding

Part D Plasma Arc Welding

4.17 General

4.18 Tungsten Electrodes

4.19 Restrictions on Variable Polarity Plasma Arc Welding

19207-12472301 Revision A Page 6 of 123

Contents

5 QUALIFICATIONS OF PROCEDURES AND PERSONNEL

Part A General Requirements

5.1 General

5.2 Qualification of Welding Procedures

5.3 Qualification of Welders, Welding Operators, and Tack Welders

5.4 Qualification Responsibility

5.5 Records

5.6 Position of Test Welds

Part B Types of Tests, Test Methods and Acceptance Criteria

5.7 Types and Purposes of Tests

5.8 Visual Examination

5.9 Tension Tests — Groove Welds

5.10 Bend Tests — Groove Welds — Plate and Pipe

5.11 Soundness Tests — Fillet Welds

5.12 Radiographic Examination

Part C Procedure Qualification

5.13 General

5.14 Limits of Qualified Positions for Procedures

5.15 Preparation of Test Weldment — Procedure Qualification

5.16 Limitation of Variables — Procedure Qualification

5.17 Tests — Procedure Qualification

5.18 Retests

Part D Performance Qualification

5.19 General

5.20 Limits of Qualified Positions for Performance

5.21 Preparation of Test Weldments — Performance Qualification

5.22 Limitation of Variables — Welder Performance Qualification

5.23 Limitation of Variables — Welding Operator Performance Qualification

5.24 Limitation of Variables — Tack Welder Performance Qualification

5.25 Tests — Performance Qualification

5.26 Retests

5.27 Period of Effectiveness

6 INSPECTION

Part A General Requirements

6.1 General

6.2 Inspection of Materials

6.3 Inspection of Welding Procedure Qualification and Equipment

6.4 Inspection of Welder, Welding Operator, and Tack Welder Qualifications

6.5 Inspection of Work and Records

6.6 Obligations of the Contractor

6.7 Nondestructive Testing

Part B Radiographic Inspection

6.8 General

6.9 Extent of Testing

6.10 Radiographic Procedures

6.11 Acceptability of Welds

6.12 Examination, Report, and Disposition of Radiographs

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Part C Ultrasonic Testing of Groove Welds

6.13 General

7 STUD WELDING

Part A General Requirements

7.1 General

Part B Arc Stud Welding

7.2 General Requirements

7.3 Material Requirements

7.4 Workmanship

7.5 Technique

7.6 Qualification Requirements

7.7 Operator and Pre-production Qualification

7.8 Acceptance Criteria — Production Welds

7.9 Mislocated Studs

7.10 Repair of Misapplied Studs

Part C Capacitor Discharge Stud Welding

7.11 General Requirements

7.12 Material Requirements

7.13 Workmanship

7.14 Technique

7.15 Qualification Requirements

7.16 Operator and Pre-production Qualification

7.17 Acceptance Criteria — Production Welds

7.18 Mislocated Studs

7.19 Repair of Misapplied Studs

8 NON-CRITICAL WELDING

Part A General Requirements

8.1 Application

8.2 Base Metal

8.3 Filler Metal

Part B Workmanship

8.4 Dimensional Tolerances

8.5 Temporary Welds

8.6 Weld Termination

8.7 Quality of Welds

9 CRITICAL WELDING (Except Ballistic Structures) Part A General Requirements

9.1 Application

9.2 Base Metal

9.3 Filler Metal

Part B Workmanship

9.4 Dimensional Tolerances

9.5 Temporary Welds

9.6 Weld Terminations

9.7 Quality of Welds

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10 BALLISTIC WELDING

Part A General Requirements

10.1 Application

10.2 Base Metal

10.3 Filler Metal

Part B Workmanship

10.4 Temporary Welds

10.5 Weld Terminations

10.6 Ballistic Certification

10.7 Macro Specimens

10.8 Quality of Welds

10.9 Ballistic Shock Test Procedure

APPENDICES

APPENDIX A – STANDARD FORMS

APPENDIX B – WELD TYPES

APPENDIX C - ALTERNATIVE RADIOGRAPHIC SAMPLING PLAN

19207-12472301 Revision A Page 9 of 123

LIST OF TABLES

Table P.1 Weld Specification Cross Reference Matrix

1.1 Aluminum Alloy Products Available for Structural Applications

1.2 Recommended Aluminum Alloy Filler Metals for Structural Welding of Various Aluminum Alloys

3.1 Limit of Acceptability and Repair of Cut Edge Discontinuities in Plate

4.1 Typical Current Ranges for Tungsten Electrodes

4.2 Typical Chemical Composition of Tungsten Electrodes

5.1 Tensile Strength of Welded Aluminum Alloys (GTAW or GMAW With No Postweld Heat Treatment)

5.2 Procedure Qualification - Type and Position Limitations

5.3 Number and Type of Test Specimens and Range of Thickness Qualified — Procedure Qualification; Complete Joint Penetration Groove Welds

5.4 Number and Type of Test Specimens and Range of Thickness Qualified—Procedure Qualification; Partial Joint Penetration Groove Welds

5.5 Number and Type of Test Specimens and Range of Thickness Qualified —Procedure Qualification Fillet Welds

5.6 Welder Performance Qualification—Type of Weld and Position Limitations

5.7 Number and Type of Test Specimens and Range of Thickness Qualified Welder and Welding Operator Qualification

6.1 Penetrameter Requirements

7.1 Minimum Fillet Weld Size for Small Diameter Studs

7.2 Minimum Required Torque Values and Tension Loads for Arc Stud Welding (F-22 Aluminum Alloy Studs)

7.3 Minimum Required Torque Values and Tension Loads for Capacitor Discharge Stud Welding (F-22 Aluminum Alloy Studs)

9.1 Maximum Acceptable Porosity in Radiographs for Any 3 in. Length of Weld (Dynamically Loaded)

10.1 Sample Inspection Frequency Table

10.2 “Consecutives” Table for Random Positions

10.3 Striking Velocity Requirements for 5083 Aluminum Alloy Using the 75 mm Aluminum M1002A Plate Proofing Projectile

10.4 Striking Velocity Requirements for 7039 Aluminum Alloy Using the 75-mm Aluminum, M1002A Plate Proofing Projectile

10.5 Striking Velocity Requirements for 5083 Aluminum Alloy Using the 57-mm Aluminum M1001A Plate Proofing Projectile

10.6 Striking Velocity Requirements for 7039 Aluminum Alloy Using the 57-MM Aluminum M1001A Plate Proofing Projectile

10.7 Striking Velocity Requirements for 2519 Alloy Aluminum Armor Weldments Using the 75-mm, M1002A Aluminum Plate Proofing Projectile

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19207-12472301 Revision A Page 11 of 123

LIST OF FIGURES

Figure

3.1 Edge Discontinuities in Cut Plate

3.2 Maximum Allowable Root Opening

3.3 Acceptable and Unacceptable Weld Profiles

5.1 Positions of Groove Welds

5.2 Positions of Fillet Welds

5.3 Position of Test Plates for Groove Welds

5.4 Position of Test Plates for Pipe or Tubing for Groove Welds

5.5 Position of Test Plates for Fillet Welds

5.6 Position for Test Pipes for Fillet Welds

5.7 Reduced Section Tension Specimens — Plate and Tubing

5.8 Alternate Reduced Section Tension Specimen for Pipe [3 in. (75 mm) Diameter or Less

5.9 Full Section Tension Specimens — Small Diameter Pipe [3 in. (75 mm) Diameter or Less]

5.10 Transverse Side Bend Specimens

5.11 Transverse Face- and Root-Bend Specimens

5.12 Longitudinal Face- and Root-Bend Specimens

5.13 Plunger-Type Guided Bend Jig

5.14 Roller-Type Guided Bend Jig

5.15 Wrap-Around Guided Bend Jig

5.16 Fillet Weld Soundness Test for Procedure Qualification — Option 1 — Plate

5.17 Fillet Weld Soundness Test for Procedure Qualification — Option 1 — Pipe

5.18 Fillet Weld Soundness Test for Procedure Qualification — Option 2 — Root Bend Test — Plate

5.19 Location of Test Specimens for Procedure Qualification — Plate

5.20 Location of Test Specimens on Welded Test Pipe

5.21 Location of Test Specimens for Square and Rectangular Tubing

5.22 Location of Test Specimens for Job Size Pipe or Tubing 1/16 in. through 3/8 in. Wall Thickness

5.23 Location of Test Specimens for Job Size Pipe or Tubing Over 3/8 in. Wall Thickness

5.24 Test Plate for Unlimited Thickness — Performance Qualification — Option 1 — All Positions

5.25 Test Plate for Unlimited Thickness — Option 2 — Horizontal Position Only

5.26 Test Plate for Limited Thickness — All Positions — Performance Qualification

5.27 Optional Test Plate for Limited Thickness — Horizontal Position — Performance Qualification

5.28 Tubular Groove Weld — Performance Qualification — Without Backing

5.29 Tubular Groove Weld — Performance Qualification — Without Backing (Alternative to Figure 5.29)

5.30 Tubular Groove Weld — Performance Qualification With Backing

5.31 Test Joint for T-, Y-, and K-connections on Pipe or Square or Rectangular Tubing — Performance Qualification

5.32 Test Weldment for Fillet Welds Only — Performance Qualification — Option 1

5.33 Location of Test Specimens on Welded Test Pipe and Square and Rectangular Tubing — Performance Qualification`

6.1 Radiographic Identification and Penetrameter Locations on Approximately Equal Thickness Joints

6.2 Radiographic Identification and Penetrameter Locations on Transitions Joints

6.3 Penetrameter Design

7.1 Stud Welding Bend Jig

7.2 Torque Testing Arrangement For Stud Welds

8.1 Permissible Undercut Values

8.2 Permissible Cracks the Stop Region of a Weld

10.1 Example of Specimen Size, or Orientation, and Markings for Ballistic Test

19207-12472301 Revision A Page 12 of 123

19207-12472301 Revision A Page 13 of 123

Ground Combat Vehicle Welding Code

— Aluminum

1. General Provisions

1.1 Scope

This Code covers welding requirements applicable to fabricating ground combat aluminum alloy structures and components. It is to be used in conjunction with appropriate complementary codes or specifications for materials design and construction. It is not intended to supplant codes developed for use in specialized fabrication, such as the ASME Boiler and Pressure Vessel Code, or aerospace codes;

it is appropriate for use in fabrication of ballistic and nonballistic primary structures, supporting structures and appurtenances. Requirements that are essentially common to all types of structures are covered in sections 1 through 7, while provisions relating exclusively to quality requirements based upon the intended use of the weldments are included in sections 8, 9 and 10.

1.2 Approval

All reference to a need for approval shall be interpreted to mean approval by the Government, or the duly designated person who acts for and on behalf of the Government in all matters within the scope of this code.

In addition, where Contractor approvals shall be required, the term Contractor shall refer to the appropriate Prime Contractor Weld Engineering and/or Quality Engineering personnel.

1.3 Materials

1.3.1 Base Metals

1.3.1.1 Aluminum alloys approved for use in

this code are listed under ASTM and former military specifications, as appropriate, in Table

1.1. Other aluminum alloys may be used only

when approved by the Government or listed as an alternate in the Technical Data Package (TDP).

1.3.1.2 To reduce the number of welding

procedure qualifications required, the following groupings of base materials listed have been established. They are based essentially on comparable base metal characteristics, such as composition, weldability, and mechanical properties:

M-Number Listing

M21 – 1060, 1100, ALCLAD 3003, 5005 5050

M22 – 3004, ALCLAD 3004, 5052, 5254, 5456,

M23 – 6005, 6061, ALCLAD 6061, 6063, 6351

M24 – 2219

M25 – 5059, 5083, 5086, 5456

M26 – A201.1, 354.0, 355.0, 356.0, A356.0, 357.0, A357.0, 359.0, 514.0, 535.0

M27 – 7005, 7039

1.3.2 Filler Metals

1.3.2.1 Filler metals shall comply with all the

requirements set forth in the latest edition of ANSI/AWS A5.10, Specification for Bare Aluminum and Aluminum Alloy Welding Electrodes and Rods. Table 1.2 lists filler alloys recommended for use with pertinent base aluminum alloys for general structural applications.

19207-12472301 Revision A Page 14 of 123

1.3.2.2 The filler metals listed below have

been arranged in the following F number groups based upon their usability characteristics.

These groupings do not imply that filler metals within the same F number grouping may be interchanged without consideration of compatibility from the standpoints of metallurgical and mechanical properties, design and service requirements, and without the approval of the Government.

1.3.2.3 Filler metals shall be stored in their

original packages or cartons, in a dry place adequately protected from the weather until actually needed at the fabrication site.

Recommendations of the manufacturer concerning special protection during storage and use shall be explicitly followed.

Group Designation

AWS

Electrode Classification

F21 ER1100, ER1188, R1100,

R1188

F22 ER5183, ER5356, ER5554,

ER5556, ER5654, R5183,

R5356, R5554, R5556, R5654

F23 ER4043, ER4047, ER4145,

ER4643, R4043, R4047,

R4145, R4643

F24 R206.0, R357.0, R-A356.0, R- A357.0, R-C355.0

F25 ER2319, R2319

Table 1.1 Aluminum Alloy Products Available for Structural Applications (see 1.3.1.1)

Sheet and

Plate

Rolled Cold

Finished Rod, Bar, and Wire

Extruded Rod, Bar, Wire and Shapes

Rolled or Extruded Structural Shapes

Seamless Extruded Tube and Pipe

Seamless Drawn Tube and Pipe

Welded Tube

Welded Fittings

Forgings

Sand Castings

Permanent Mold

Investment

High Strength Castings

Alloy No.1

ASTM

B209

ASTM

B211

ASTM

B221

ASTM

B308

ASTM

B241

ASTM

B429

ASTM

B210

ASTM

B483

ASTM

B313

ASTM

B361

ASTM

B247

ASTM

B26

ASTM

B108

ASTM

B618

ASTM

B686

Wrought Alloys

AA 1060

AA 1100

AA 2219

X X

[X]2

X X

[X]

X X [X]

X X [X]

X X

X

[X]

AA 2519 (ref MIL-A-[TBD])

AA 3003

Alclad

AA 3004

X X X

X X X X

X X

X

X X

X

X

AA 5052

AA 5083

AA 5086

X X X

X X X X

X X X

X X

AA 5154

AA 5254

AA 5454

X X X

X

X X X

AA 5456

AA 5652

AA 6005

X

[X]

X

AA 6061

Alclad

AA 6063

X

[X] X

AA 6351

AA 7005

(ref MIL-A-46063)

X

[X]

Cast Alloys

AA A201.0

AA 354.0

AA C 355.0

[X] [X]

AA 356.0

AA 356.0

AA 357.0

X [X]

X [X] [X]

AA A357.0

AA 359.0

AA 443.0

AA 514.0

AA535.0

Notes:

1. Wrought Alloys 1xxx, 3xxx, 5xxx, and cast alloys 4xx.x and 5xx.x are nonheat treatable alloys. Wrought alloys 2xxx, 6xxx, and 7xxx and cast alloys x2xx.x and x3xx.x are heat treatable alloys.

2. [X] indicates a revision to ANSI/AWS D1.2-83

AA = Aluminum Association No.

19207-12472301 Revision A Page 15 of 123

Table 1.2* Recommended Aluminum Alloy Filler Metals for Structural Welding of Various Base

Aluminum Alloys (see 1.3.2.1)

Base Metal to Base Metal

Alclad 3003

A201.1

Alclad

56523

514.0 535.0

52543

Alclad 6061

354.0 C354.0

356.0 A356.0 357.0

A357.0 359.0 443.0

356.0, A356.0, 357.0, A357.0, 359.0, 443.0

(8)

(5),(8)

(8)

(8)

(4),(8)

(7)

(7)

(4)

(4)

(8),(9)

(8)

(5),(6),(

8)

(6),(8),(9)

354.0, C355.0 4145 (5),(8)

(5),(8),(

10)

(5),(8)

(5),(8)

(8)

NR NR NR 4043

(8)

(5),(8)

(5)(8)

(5),(6),(

8)

7005 5356 (5),(7)

(5),(8)

(5),(7)

(5),(7)

(4)

(7)

(7)

(4)

(4)

(4),(5),(8)

(7)

6005, 6061, Alclad 6061, 6063, 6351

(8)

(5),(8)

(4),(5)

(7),(8)

(4),(5)

(7)

(7)

(4)

(4),(5)

(4),(8),(13)

5454 4043 (7),(8)

(8)

(4),(5)

(4),(5)

(4),(5)

(7)

(7)

(4)

(5),(7), (8)

5154, 52543 4043

NR 5356

(4)

(4)

(4)

(7)

(7)

(4)

5086, 514.0, 535.0

(7)

NR 5356

(7)

(7)

(7)

(7)

5083, 5456 5356

NR 5356

(7)

(7)

(7)

5052, 56523 4043

(8)

(7),(8)

(7),(8)

(4),(5)

5005, 5050 4043 (8),(11)

(5)

(7),(8)

(8),(11)

3004, Alclad

(7),(8)

(5)

2219, A201.1

(5),(8)

(5),(8), (9)

1060 1100 3003, Alclad

(5),(6),(8), (12)

Notes:

1. The filler metal shown for each combination of base alloys is that most commonly used. However, the specific filler metal depends upon usage and type of joint, and in a number of cases, acceptable alternates are recommended. [Notes (4) – (13)]. When NR is indicated, welding that combination of base alloys is not recommended.

2. Filler metals conform to the requirements of ANSI/AWS A5.10.

3. Exposure to specific chemical, or a sustained high temperature [over 150ºF (66ºC)] may limit the choice of filler metals. Filler alloys 5183, 5356, 5556, and 5654 should not be used for sustained elevated temperature service. Filler alloy 5654 is suitable for use with base alloys 5652 and 5254 for hydrogen peroxide service.

4. 5183, 5356, 5554, and 5654 may be used. In some cases, they provide (1) improved color match after anodizing treatment, (2) higher weld ductility, and (3) higher weld strength. 5554 is suitable for elevated temperature service.

5. 4043 may be used for some applications.

6. Filler with the same analysis as the base metal alloy is sometimes used/

7. 5183, 5356, or 5556 may be used.

8. 4047 may be used for some applications.

9. 4145 may be used.

10. 2319 may be used.

11. 1100 may be used.

12. 1188 may be used.

13. 4643 may be used. This is useful primarily when 1/2 inch (12.7 mm) and thicker weldments are post weld solution heat treated and precipitation age hardened.

* In addition to these alloys, 7039 aluminum armor may be welded to itself, or to 5083 or 5086 alloys using 5356 filler metal.

19207-12472301 Revision A Page 16 of 123

1.3.3 Shielding Gases

1.3.3.1 The shielding gas in conventional

welding of aluminum shall be welding-grade argon, complying with CGA specification Grade C minimum. Where special circumstances exist, i.e., the need for deep penetration (as in welding very thick sections), the use of welding-grade helium or a mixture of welding grade argon and welding-grade helium may be used in accordance with the requirements of section 5.16.

1.3.3.2 Shielding gases shall be stored in and

used from the containers in which they are supplied or from a central storage tank distribution system which is replenished by the gas supplier.

The entire handling system shall be designed to prevent contamination.

1.4 Welding Processes

This code covers the requirements for welding aluminum alloys by the following processes:

(1) GMAW — gas metal arc welding

(2) GTAW — gas tungsten arc welding

(3) PAW-VP — plasma arc welding with variable polarity.

(4) SW — stud welding

(5) GMAW-AU, -ME, and -RO — automatic, mechanized, or robotic gas metal arc welding

The welding procedures for these processes shall comply with the provisions of sections 1 through 5 and, in addition, sections 8, 9, or 10, as applicable.

1.5 Equipment Calibration

The manufacturer is required to develop and maintain a welding equipment calibration program. This program shall consist of, as a minimum, an annual comparison check of the machine output with instrumentation calibrated using standards traceable to the National Institute of Standards and Technology (NIST). The standard may be a load bank, voltmeter/ammeter, clamp-on meter, etc.

Machine output for amperage and voltage must be within ± 10% of full scale. Proper documentation and evidence of the implementation must be maintained and is subject to random audit. Location for calibration shall be as follows:

• GMAW – At wire feeder

• GTAW – At power supply

• All other processes – As close as practical to the welding process

1.6 Definitions

The welding terms used in this Code shall be interpreted in accordance with the definitions given in the latest edition of ANSI/AWS A3.0, Standard Welding Terms and Definitions.

Terms not included in ANSI/AWS A3.0 are defined below:

Reenetrant corner – A corner directed inward (as opposed to an outside corner)

Fins – Metal on a casting caused by an imperfect mold or die

Flange – A rib or rim provided for strength, for guiding, or for attachment to another object

Transition area – An area in which the thickness varies from thicker to thinner

Shrinkage – A shrinkage crack

Cope holes – A hole formed to conform to the shape of another member

Bearing joint – Welded joint positioned to absorb the load

Faying surfaces – The mating surface of a member that is touching or in close proximity to another member to which it is to be joined

Built-up members – A member that has been clad, buttered, or in some way built up with weld metal

Modified PQR – A PQR that has been developed from existing procedures qualified from a welding military standard or specification, and grandfathered into an AWS PQR format

Modified WPS – A WPS that has been created from a modified PQR(s) developed from an existing workmanship sample per MIL-STD or specification.

1.7 Welding Symbols

Welding symbols used in drawings, sketches, erection plans, procedure specifications, etc., shall be those shown in the latest edition of ANSI/AWS A2.4, Symbols for Welding, Brazing, and Nondestructive Examination. Special conditions shall be fully explained by added notes or details.

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1.8 Safety Precautions

Note: This Code may involve hazardous materials, operations, and equipment. The Code does not purport to address all of the safety problems associated with its use. It is the responsibility of the user to establish appropriate safety and health practices. The user should determine the applicability of any regulatory limitations prior to use.

Adequate safety precautions, including ventilation of the work area shall be taken in accordance with the requirements of the latest edition of ANSI/ASC Z49.1, Safety in Welding and Cutting.

1.9 Standard Units of Measurement

The values stated in U.S. customary units are to be regarded as standard.

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3. Workmanship

3.1 General

3.1.1 All applicable subsections in this section

shall be adhered to in the production and inspection of welded assemblies and structures produced under this Code.

3.1.2 All welding and cutting equipment shall be

so designed and manufactured and shall be maintained in such operating condition that qualified welders, welding operators and tack welders are able to follow the procedures and attain the results prescribed elsewhere in this Code.

3.1.3 Welding shall not be done when the

parent metal temperature is lower than 55° F. This does not mean the ambient environmental temperature, but the temperature in the immediate vicinity of the weld. If the ambient environmental temperature is below 32° F, a heated structure or shelter may be provided which will maintain the temperature adjacent to the weldment at 55° F or higher. When the temperature of the weld area and surrounding base metal is below the allowed minimum temperature, the base metal shall be preheated, but not to exceed 250° F, so that the parts on which weld metal is being deposited are at, or above, the allowed minimum temperature for a distance equal to the thickness of the parts being welded, but not less than 3 in. both laterally and in advance of the welding. This heating is to be done before welding is started to drive moisture from the region of the weld.

3.1.4 Welding shall not be done when the

surfaces are wet or exposed to rain, mist, snow, sleet, frost, or excessive wind, or when welders, welding operators or tack welders are exposed to such inclement conditions.

3.1.5 The sizes and lengths of welds shall be

those specified by the design requirements and detail drawings.

3.1.6 The locations of welds shall not be

changed from those shown on the drawings.

3.1.7 The use of anti-spatter compound shall be

prohibited.

3.2 Preparation of Base Material

3.2.1 Edge preparation can be accomplished

by shearing, sawing, plasma arc cutting, chipping, planing, milling or routing. Grinding of aluminum, except as a final weld contouring and finishing operation, is not recommended.

3.2.1.1 When grinding is necessary, care

shall be taken to select nonloading type abrasives specifically intended for use on aluminum, and the abrasives shall be maintained free of lubricants and other foreign material.

3.2.1.2 All exposed cut edges on alloy 7039

must be buttered if not part of a weld joint.

3.2.2 Surfaces and edges to be welded shall be

smooth, uniform, and free from fins, tears, and cracks.

3.2.3 In plasma arc cutting, the arc shall be

adjusted and manipulated so as to avoid cutting beyond (inside) the prescribed lines. The surface roughness of the cut surfaces shall be no greater than that defined by the American National Standards Institute (ANSI B46.1, Surface Texture) value of 1000 µin. for material up to 4 in. thick and 2000 µin for material 4 in. to 8 in. thick, except that members not subject to calculated stress at the ends may meet the surface roughness value of 2000 µin. Roughness exceeding the permissible amount and occasional notches or gouges more than 3/16 in. deep, on otherwise satisfactory surfaces shall be faired into the cut surface by machining or grinding to a slope not exceeding one in ten. In cut edges, occasional notches or gouges less than 7/16 in, deep in material up to 4 in. in thickness, or less than 5/8

in. deep in material more than 4 in. thick may, with the approval of the Material Review Board (MRB), be repaired by welding in accordance with approved repair procedures.

3.2.4 Visual Inspection and Repair of Cut

Edges

3.2.4.1 In the determination of limits of

internal discontinuities revealed on sheared or cut edges and caused by tearing, inclusions, or delamination (seldom encountered in aluminum products), the amount of metal removed shall be the minimum necessary to remove the discontinuity or to determine that the permissible

19207-12472301 Revision A Page 20 of 123 limit of the discontinuity is not exceeded. The removal of metal for this purpose may be done from either the plate surface or a cut edge. Cut edges may exist at any angle with respect to the direction of rolling.

3.2.4.2 The limits of acceptability and the

repair of edge discontinuities shall be in accordance with Table 3.1, in which the length of the discontinuity is the visible long dimension on the cut edge, and the depth is the distance that the discontinuity is determined to extend into the plate from the cut edge.

3.2.4.3 For discontinuities with both length

and depth greater than 1 in., discovered by visual examination of the cut edge and determined to exceed 1 in. in depth for each discontinuity exhibited before welding or during examination of welded joints by radiographic or ultrasonic examination, the following procedures shall be followed:

(1) Where discontinuities, such as W, X, or Y in Figure 3.1, are discovered prior to completing the joint, the size and shape of the discontinuity shall be determined by ultrasonic inspection

(2) For acceptance, the area of the discontinuity (or the aggregate area of multiple discontinuities) shall not exceed 4% of the plate area (length x width) with the following exception: If the length of discontinuities on any transverse section, as measured perpendicular to the plate length, exceeds 20% of the plate width, the 4% allowance shall be reduced by the percentage amount of the length exceeding 20% of the plate width. (For example, if the length of a discontinuity is 30% of the plate width, the area of discontinuity cannot exceed 3.6% of the plate area.) The discontinuity on the cut edge of the plate shall be gouged out to a depth of 1 in.

beyond its intersection with the surface by chipping or gouging, and blocked off by welding in layers.

(3) If a discontinuity, Z, not exceeding the allowable area in 3.2.4.3 (2) is discovered after the joint has been completed and is determined to be 1 in or more away from the weld, no repair of the discontinuity is required. If the discontinuity Z is less than 1

in. away from the weld, it shall be gouged out to a distance of 1 in from the fusion zone of the weld by chipping or gouging.

The groove shall then be filled by welding.

Repair by welding shall be subject to the same NDT requirement as other groove welds.

(4) If the area of the discontinuity W, X, Y, or Z exceeds the allowable limits in 3.2.4.3 (2), the plate or subcomponent shall be rejected and replaced, or repaired at the discretion

Table 3.1 Limit of Acceptability and Repair of Cut Edge Discontinuities in Plate (see 3.2.4.2)

Description of Discontinuity Plate Repair Required

Any discontinuity 1 in. in length or less None, need not be explored

Any discontinuity over 1 in. in length and 1/8 in.

maximum depth

None, but the depth should be explored*

Any discontinuity over 1 in. in length with depth over 1/8

in. but not greater than 1/4 in.

Remove, need not weld

Any discontinuity over 1 in. in length with depth over 1/4

in. but not greater than 1 in.

Completely remove and weld. Aggregate length of welding shall not exceed 20% of the length of the plate edge being repaired.

Any discontinuity over 1 in. in length with depth greater than 1 in.

See 3.2.4.3

* A spot check of 10% of the discontinuities on the cut edge in question should be explored to determine depth. If the depth of any one of the discontinuities explored exceeds 1/8 in., then all of the discontinuities remaining on that edge shall be explored to determine depth. If none of the discontinuities explored in the 10% spot check have a depth exceeding 1/8 in., the remainder of the discontinuities on that edge need not be explored.

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Figure 3.1 — Edge Discontinuities in Cut Plate (see 3.2.4.3) of the Material Review Board (MRB). The aggregate length of weld repair shall not exceed 20% of the length of the plate edge, without the approval of the MRB.

(5) All repair welding shall be in accordance with a qualified procedure and the applicable subsections of this code, and performed by a qualified welder.

3.2.5 Reentrant corners, except for the corners

of weld-access cope holes adjacent to a flange, shall have a fillet radius of no less than 1/2 in.

except it shall be 3/4 in. for major structural components. The fillet and its adjacent cuts shall meet without offset or cutting past the point of tangency.

3.2.6 Machining, sawing, gouging, or chipping

may be used to back gouge, remove temporary welds, or remove unacceptable work or metal.

3.2.7 All surfaces to be welded shall be free

from thick aluminum oxide, paint, grease, cutting fluids and moisture.

3.2.7.1 Oily material shall be degreased

either chemically or with an approved solvent.

Caution should be exercised in the use of flammable solvents. The health and safety concerns should be recognized (see ANSI/ASC Z49.1).

3.2.7.2 Thick aluminum oxide shall be

removed with a stainless steel brush or other approved material, or by chemical methods.

3.2.8 Degreasing should be followed by scratch

brushing of surfaces to be welded, with a hand or power-driven stainless steel brush to ensure thick aluminum oxide is removed. In multi-pass welds scratch brushing may be necessary between passes. The brushes should be kept exclusively for use with aluminum and be kept clean.

The interval between any scratch brushing of the joint and welding shall not exceed 24 hours. If contamination with dirt or moisture occurs after cleaning and prior to welding, the joint shall be recleaned.

3.3 Assembly

3.3.1 Abutting parts to be joined by groove

welds shall be properly aligned. Where the parts are effectively restrained against bending due to an offset in alignment, an offset not exceeding 10% of the thickness of the thinner part, but in no case more than 3/16 in., may be allowed as a departure from the theoretical alignment. In correcting misalignment in such cases, the parts shall not be drawn in to a greater slope than 1/2

in. in 12 in. Measurement of offset shall be based on the midplanes of the parts, unless otherwise shown on the drawings.

3.3.2 Welding grooves which vary from those

shown on the detail drawings and procedure specifications shall be referred to MRB.

3.3.3 Parts to be joined by partial joint

penetration groove welds parallel to the length of the member, except for bearing joints, shall be brought into contact as closely as practicable.

The root opening between parts shall not exceed .156 in. except in cases involving rolled or extruded shapes, or plates 3 in. or more in thickness. When after straightening, the root opening cannot be closed sufficiently to meet this tolerance, a maximum root opening of 5/16 in. is acceptable, provided a sealing weld or suitable backing material is used to prevent melt-through.2

The maximum root opening for slip fit joints, reference Figure 3.2, with integral backing shall be 5/16 in. for extruded shapes or plates or as otherwise specified in the appropriate weld procedure.

3.3.4 Parts joined by fillet welds shall be

brought into contact as closely as practicable. The separation between parts shall not exceed .156

in. unless nominal design exceeds .156 in. If separation exceeds .062 in., the leg of the fillet shall be increased by the amount of the root opening.

3.3.5 The work shall be positioned for flat-

position welding whenever practicable.

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3.3.6 The separation between faying surfaces

of lap joints and of butt joints landing on a

Figure 3.2 — Maximum Allowable Root Opening (see 3.3.3) backing shall not exceed .156 in. The use of filler plates is prohibited except as specified on the drawings.

3.3.7 Members to be welded shall be brought

into correct alignment and held in position by fixtures and strongbacks, bolts, clamps, wedges, guy lines, struts, other suitable devices, or by tack welds until the welding has been completed. The use of fixtures is recommended when practicable.

The fixtures shall have sufficient stiffness and strength to counteract the forces resulting from the temperature changes in the weldment.

Similarly, tack welds shall have sufficient effective throat or weld size and length to develop the necessary strength.

3.3.7.1 Tack welds shall be made in

accordance with a qualified welding procedure, by a qualified tack welder, and subject to the same quality requirements as the final welds. Tack welds that will be incorporated into the final weld shall be made with filler metal of the same composition and shall be cleaned thoroughly before incorporation. Tack welds not incorporated into final welds may be removed by grinding, chipping, machining or plasma gouging unless they have been installed for the purpose of support and do not interfere with fit, function or inspection.

3.3.7.2 Temporary welds shall be made by a

qualified welding procedure, by a qualified welder, and be subject to the same quality requirements as the final weld. Strongbacks, clips, hangers and other temporary parts that have been welded in place to facilitate assembly shall be removed and the welds made flush with the metal surface.

Surface defects that extend below the plane of the metal surface shall be repaired in accordance with an approved repair procedure.

3.4 Control of Distortion and

Shrinkage

3.4.1 In assembling and joining parts of a

structure or of built-up members, and in welding reinforcing parts to members, the procedure and sequence shall be such as will minimize distortion and shrinkage.

3.4.2 Insofar as practicable, all welds shall be

deposited in a sequence that will balance the applied heat of welding while the welding progresses.

3.4.3 A welding sequence and distortion-control

program shall be prepared and/or approved by Weld Engineering and made available to Production before the start of welding on a member in which shrinkage or distortion is likely to affect the adequacy of the member or structure.

3.4.4 Weld components may be preloaded prior

to welding to reduce or eliminate weld distortion.

3.4.5 Joints expected to have significant

shrinkage should usually be welded before joints expected to have lesser shrinkage

3.4.6 In making welds under conditions of

severe external shrinkage restraint, the welding shall be completed or completed to a point that will ensure freedom from cracking, before the joint is allowed to cool.

3.5 Weld Profiles

3.5.1 The faces of fillet welds may be slightly

convex, flat, or slightly concave as shown in Figures 3.3(A) and 3.3(B), with none of the unacceptable profiles shown in Figure 3.3(C).

Except at outside corner joints, the convexity, C, of a weld or individual surface bead shall not exceed 0.07 times the actual face width of the weld or individual bead, respectively, plus 0.06 in.

3.5.2 Groove welds shall be made with slight or

minimum reinforcement unless otherwise specified. In the case of butt and corner joints, the weld reinforcement and melt-through height shall not exceed the values listed in Figures

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Figure 3.3 — Acceptable and Unacceptable Weld Profiles (see 3.5)

3.3(D) and 3.3(E) and shall have a gradual transition to the plane of the base metal surface.

The weld shall be free of discontinuities of the types shown for butt joints in Figure 3.3(F).

3.5.3 Surfaces of butt joints required to be flush

shall be finished so as not to reduce the thickness of either of the base metals or weld metal by more than 1/32 in. or 5% of the thickness, whichever is smaller, or leave reinforcement that exceeds 1/32 in.

3.6 Rework/Repairs

This section is provided for guidance in the case that rework/repairs are required. Repairs shall be performed in accordance with approved standard repair procedures, which shall take precedence over this section.

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Definitions for rework and repair are as follows:

Rework – The removal and replacing of an existing weld, addition or deletion of weld metal to bring a weld to drawing requirement, or the removal and replacement of a mislocated component.

Repair – Through the welding process, the restoration of base metal to the correct configuration. This includes mislocated holes, slots, undersize and oversize conditions.

3.6.1 The removal of weld metal or portions of

the base metal may be done in accordance with section 3.2.6. The removal shall be done so that the remaining weld metal and base metal are not nicked or undercut. Unacceptable portions of the weld shall be removed without substantial removal of base metal. Metal added to compensate for any deficiency in the size of the weld shall be deposited by a qualified welder with filler of the same composition in accordance with an approved welding procedure The surfaces shall be cleaned thoroughly before welding.

3.6.2 The contractor has the option of either

reworking an unacceptable weld, or removing and replacing the entire weld, except as required by section 3.6.3. If the contractor elects to rework the weld, it shall be corrected as follows:

3.6.2.1 Overlap or Excessive Convexity.

Excess weld metal shall be removed by machining, chipping, or grinding.

3.6.2.2 Excessive Concavity of Weld or

Crater, Under-size Welds, Undercutting.

Surfaces shall be prepared and additional weld metal deposited in accordance with the specified welding procedure.

3.6.2.3 Excessive Weld Porosity or

Incomplete Fusion. Unacceptable portions shall be removed and the area rewelded in accordance with the specified welding procedure.

3.6.2.4 Cracks in Weld or Base Metal. The

extent of the crack shall be ascertained by use of visual, or by dye penetrant, X-ray examination, or other NDT means. The crack shall be removed and the area rewelded in accordance with the specified welding procedure, as required in sections 8, 9, or 10. If dye penetrant is used, all traces of penetrant and developer shall be removed before rewelding is begun.

3.6.3 If the contractor elects to remove and

replace the entire weld, the procedure approved for use on the original weld shall be used and such replacement welds shall be recorded.

3.6.4 The reworked or replaced weld shall be

tested or examined by the method originally used and the same technique and quality acceptance criteria shall be applied.

3.6.5 Members distorted by welding shall be

straightened at ambient temperature by mechanical means. If localized heating is to be applied in any straightening operation, the complete procedure shall be approved by the Government.

3.6.6 Approval of the Weld or Quality Engineer

or of Production supervision shall be obtained for such corrections as weld repairs to mill defects in the base metal and repair of cracks in accordance with approved repair procedures.

3.6.7 If, after an unacceptable weld has been

made, work is performed which has rendered that weld inaccessible or has created new conditions which make correction of the unacceptable weld dangerous or ineffective, then the original conditions shall be restored by removing the added welds or members, or both, before the corrections are made. If this is not done, the weld must be submitted to MRB for disposition.

3.7 Cleaning Of Completed Welds

3.7.1 Welded joints shall not be painted or

otherwise covered before the welding is examined and approved.

3.7.2 Weld spatter shall be removed only when

its presence affects subsequent component fit, or where on the finished product it results in a potential personnel safety hazard.

Footnotes:

1 The requirements of 3.2.4 are not applicable to cases in which the stress is applied normal to the plate surface.

2 Backing to prevent melt-through may be of ceramic glass tape, austenitic stainless steel or an alloy with the M-number classification of the base metal. The backing shall be in intimate contact with the root side of the components being welded. If aluminum alloy backing is to be left permanently in place, it may be attached by continuous fillet welds.

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4. Technique

Part A

General Requirements for Gas Metal Arc, Gas Tungsten Arc and Plasma

Arc (Variable Polarity) Welding

4.1 Material Requirements

4.1.1 The Filler metal shall comply with all the

requirements set forth in the latest edition of ANSI/AWS A5.10, Specification for Bare Aluminum and Aluminum Alloy Welding Electrodes and Rods. (Note: When required, the filler metal must have the capability of meeting radiographic soundness requirements.)

4.1.2 Filler metal alloys to be used with specific

base metals and combinations of, base metals shall be as shown in Table 1.2.

4.1.3 The filler metals used shall conform to

ANSI/AWS A5.10. The contractor or manufacturer shall have a method of verification (purchase orders, packing slips, etc.) that provides evidence the filler metals conforms to

ANSI/AWS A5.10.

4.2 Welding Processes

The welding process shall be either gas metal arc (GMAW), pulsed gas metal arc (GMAW-P), gas tungsten arc (GTAW), plasma arc with variable polarity (PAW-VP), automatic gas metal arc (GMAW-AU), mechanized gas metal arc (GMAW- ME), or robotic gas metal arc (GMAW-RO).

4.3 Shielding Gases

4.3.1 Argon, helium, or mixtures of argon and

helium used for shielding shall be a welding grade having a dew point of -63° F or lower.

4.3.2 The contractor or manufacturer shall

maintain records of the gas manufacturer's certification that the gas or gas mixture is suitable for the intended application and conforms to the dew point required in 4.3.1.

4.4 Preheat Requirements

Preheating is sometimes used for welding thick aluminum sections to avoid cold-start defects, to achieve heat balance with dissimilar thicknesses, or to remove moisture. Special care shall be taken to ensure close temperature control, particularly when fabricating the heat treatable aluminum alloys and the 5000 series aluminum alloys containing more than 3% magnesium.

Preheating temperatures for these types of alloys shall not exceed 250° F. Holding times at this temperature shall not exceed 15 minutes.

4.5 Interpass Temperature

Requirements

When fabricating the heat treatable aluminum alloys and the 5000 series alloys containing more than 3% magnesium, interpass temperatures shall not exceed 275° F to provide optimum weld properties and to decrease the possibility of sensitization to exfoliation and stress corrosion cracking.

4.6 Arc Strikes

Arc strikes outside the area of permanent welds should be avoided on any base metal. Blemishes caused by arc strikes shall be finished to a smooth contour when their presence affects form, fit, or function, and checked to ensure no loss of soundness of the base metal. Cracks caused by arc strikes shall be removed. The cracks shall be repair-welded and the weld finished flush with the metal surface.

4.7 Cleaning Prior to Welding

All joint faces and the surfaces adjacent to the area to be welded shall be prepared in accordance with 3.2.8.

4.8 Weld Termination

4.8.1 Welds shall be started and stopped in a

manner that ensures sound welds. Whenever possible and appropriate, the starting and stopping shall be done by the use of extension bars or run-on and run-off plates.

4.8.2 Extension bars or run-on and run-off

plates shall be removed (preferably by mechanical cutting) upon completion and cooling of the weld. The ends of the weld shall be made smooth and fit flush with the edges of the adjacent parts.

4.8.3 When it is impossible to…