DOD-STD-2185.pdf

DEPARTME:NT OF THE NAVY

NAVAL 5URI'ACe: WAHF-II.RF CENTER

CAJ1DI:OI=lOCK DiVISION

From: Connnandcr. Cardcrock Division, Naval Surface Warfare Center Philaddphja. PA 19112-5083

To: Distribution

CHAI\GE ~OTJCE TO DOD-STD-21S5

Sir:

NAVAl... SHIP SYSTEMS eNGINEERING STAT.ON

PHILADELPHIA. ,",A 19n2·!iOa;J

Ser 9323it98

~~~''' .. Y ",(ii, h 1':"1 oel" (),~ 1.G01

The purpose ofthif> lentr ls to provide interim guidance regarding propelh:r stress rdief requirement .. until DOD· 5TD-2185 is revised. TI1is lcner applies to a1l propellers which require str~ss relief in accordance with DOD-STD· 2185. Stress relief is a critical process til ensure satisfactory perfomlance ofpropeUers in service. DOD-STD·2.lSS, section 5.5.2.3 contains the thermocouple ;f.lcatlon rcquirel'nents for propeller stress relief.

We request thal you take for action to repJace seer-ion 5.5.1.3 of DOD-STD~2185 and all company procedures and instructions for locating thermocouples when performing stress relief with enclosure: (I).

'The technical point of contact for this change' notice i$: Rick Vath, ~.·.215) 897-8506, val h!!g~~~h~@'yE!!!!.

Disnibution:

Wartsila Lips, Chesapeake. VA \Vartsila Lips, Poulsbo. \"VA RR't--TJ\·1 Walpole. 1\'1.'\ R.R."""'1\1 Pas-cagoula, ~1$ Pacific Marine Propellers Inc. San Diego, CA Jolmson Ship Propellers, Chesapeake. VA >JNSY det ~TfPc. Philadelphia. PA (\\.'. Keating) PSNSY 260.17 (M. Celich) ~AVSF.A 05H (P. ~1oort) DCMA Baltimore. )'1D QAR (J. Clark) DCMA S:m DiegQ. CA QAR (K. Gree.n) DCMA Boswn. M;\ QAR (J.lwuc) DCMA Bim'lingham, AL QAR (S. Hudgies) DCIv1A Seattle. \VA QAR (B. Czausz)

End: (1) Change Notice DOD- STD-2185

6A .... ;

/' ~/<C:~ ~

< .. ~.;'in ?1(> L<t:;J RM Zekas C/ Oranch Manager Diesel Engine and Power Transmission By dirtction of the Commanding Officer

5.5.2.3 Temper.ature recording.

Sm:ss Relief Thermocouple Location Requirements 9/26102

A record of furnace alr temperaturc~ as '.vell as propeller krnpcrarul'e.s. ~h31i be obtained during the stress reliefhcat lfeatmeut cycle at inten,lals nol exceeding] hour. Propeller lemperatures shall be monitored by thermocouples ]()catcd in the foHowing positions;

(at On the lOp face of rhe bub.

(b) On the botTOm face of the bub.

(e) At the eenter (mld·lcngth) of the bon:.

(d) On the outside center (mid·1cnb:rth) of the hub.

(e.) At tht I;>~nlcr (O.6R and mid-..:hord) of the pressure and ~m~[ton face~ of 1\\'0 opposite blades.

(1) On the underside of alllhe [)lades within 1 inch from {he tip along the centerline to measure propeller tip lemper:Jture.

fg f Located ill m~Q.surc rurn~cc 21mbl¢lll (;:m} It:rnpaamre .and furnace floor ll:mpl'ranut:.

Enclosure (1)

NOTE: DOD-STD-2185 has been as a Standard Practice. The cover page has been changed for Administrative reasons. There are no other changes to this Document.

AMSC N/A

DEPARTMENT OF DEFENSE

STANDARD PRACTICE

DOD-STD-2185(SH)

28 OCTOBER 1986

SUPERSEDING

NAVSEA 0991-LP-023-3002

15 July 1982 (See 6.4)

REQUIREMENTS FOR REPAIR AND STRAIGHTENING

OF BRONZE NAVAL SHIP PROPELLERS

FSC 2010

Approved for public release; distribution is

DOD-STD-2185(SH)

28 October 1986

DEPARTMENT OF THE NAVY

NAVAL SEA SYSTEltS CXJHHAND

Washington, DC 20362-5101

Requirements for Repair and Straightening of Bronze Naval Ship Propellers

1. This Hilitary Standard 1s approved for use by the Naval Sen Systems Command, Department of the Navy, and 1s available for use by all Departments and Agencies of the Department of Defense.

2. Beneficial comments (~eeommend8t1ons. additions, deletions) and any pertinent data which may be of use 1n improv1ng th1s document should be addressed to:

COmmander, Naval Sea systems Command, SEA SSZ3, Department of the Navy, Washington, DC 20362-5)01 by using the self-addressed Standardi~ation Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter.

c

DOD-STD-218S( SH)

FOREWORD

1. This standard contains information and requirements for the repair of --~ronZ-e· Naval ehl-p propetlers ~ .. - - .--. .r- .

Paragraph 1.

1.1 1.2

2.

2.1 2.1.1 2.1.2 2.2 2.3

4 ..

4.1 4.2 4.2.1 4.2.2

4.2 .. 3

4.2 .. 3d 4.2.3.2 4.2.4 4.3 4.3.1 4.3.2 4.3~3 4.3.4 4.3.5 4.3.6 4.4

5 ..

5.1 .5.1.1 5.1.2 5 .. 1.3 5.1.4 5.1.5 5.1.5.1 5.1.5.1.1 5 .. 1.5.1.2 5.1.5.2 5.1.5.2.1 5.1.5.2.2 5.1.5.2.3

DOD-STD-218S(SH)

28 October 1986

CONTENTS

SCOPE , ... ---------------,-----

Scope ----------------------- Approval --~-------------------

REFERENCED OOCUMENTS ----------------

Government documents ------------------------------ Specifications and standards ----------- Other Government publications --------- Other publications --------------- Order of precedence ---------------------------------

DEFINITIONS -------------------------

General ------------------------------. --- Definitions -----------------------------

CENERAL. REQUtR!KENTS -------------------------- RespOnsibility ------------------------------------- Quallty assurance ------------------ General -------------------------------------------- Quality assurance system --------------------------- Records --------------------------------- Ceneral ------------------------------------------ Record form ---------------------------- Noncompliance ---------------------------------- Welding qualifications ----------------------------- Welding procedure qualification ---------- Welding procedure and qualification approval ----- Alternate process --------------------------------- Procedure requirement ----------------------------- Welder performance qualification ------------------- Welding equipment ------------------------- Atmosphere exposure --------------------------------

DETAILED REQUIREMENTS -------------------------------

Materials ------------------------------ Materials for repair ---------------------- Material substitution approval ----------------~ Specification deviations ------------------ Propeller material identification ----------------- Zinc equivalent and alpha/beta determination ------- Zinc equivalent ---------------- Zinc equivalent requirement ------------- Zinc equivalent sampling plan -------------------- Alpha/beta determination ------------------- Alpha/beta requirement --------------------------- Alpha check sampling plan ---------------- Replica technIque for determination of alpha/beta content -----------, Propeller handling ------------------- General ----.. --~-------------------------iv

Page

I, I

S S S 6 , DOD-STD-218S(SH)

CONTENTS - COntinued

._ Parilyaph _.5.",3._ ..... -- 5.3.1 5.3.2

-Welding ~, , .. -- -------- ' ... _ .. --welding prerequisite ------------------------------- Preheat .... ------------------

1.5

IS

Pigure

Table

' .. J.] 5.3.4

5.3 • .5 S.3.6 5.3.7 5.3.7.1 5.3.8 5.4 5.4.L 5.4.2 5.4.)

5.4.4 5.oS 5.5.1 5 .. 5.1.1 5.5.2 5.S.2.1

.5 .. 5.2.2

5.5.2.3

5.5.2.3 .. 1 5.5.3 S.S.3.1 5.5.3.2 5.5.3.3 5.5.4 5.5.5 welding requirements -----~--------------------- Repairs to critical areas ----------- Joiot design and position ------------ Peening -- .----------- Repair ~ceptlon8 ----------- SlDall defects ----- ... ------------ Weld repair inspection ---------------------------- Straightening ------------~- .------------------

Cold straigbtening ------------------- Hot straightening --------------------------------- Inspection after strsightening -------------- Stress relief ------------------------------------- General ------.... ----------------- Manganese-nIckel-aluminum bronze propel leTs -------- Furn8ce stress relief ----------------------------- FUrnace stress relief of manganese bronze and' nlckel-manganese bronze --------------------------

Furnace stress relief of manganese-nickel-aluminum

Temperature recording ----------------------------- "Ibermocouple attachment ----------... --------- Local stress relief ------------------.-~-----------

Major repairs ------------------------------------- Minot repairs ----.. -----------------------Propeller support --__________________________ w ____ -

Grinding -----------.-------------------------------l8

6. NotES --------.... --------------------------- 18

6.1 Intended use -------------------------- 18

6.2 Data requirements ------------------------~--------- 19

6.4 Subject term (key word) listing --------~-~--------- 20

6.5 Supersession ----------------------------~--------~- 20

1.

2 ..

J.

I.

II.

Ill.

IV.

FIGURES

Blade critical area ----------------------------------- 21 Typical gouge preparation for welding repair ----- 22 typical joint design for blade tip repair ------- 23

TABL-£S

Welding procedure qualification tensile requirements -- 7 Welding processes and filler metals ------- 9 Welding processes ond heat1ng requirements ------------ 13 Heating requirement8 for straightening 15 v/vl

THIS PAGE INTENTIONALLY LEFT BLANK

I. SCOPE

DOD-STD-218S(SH)

28 October 1986

1.1 Scope. This standard eovers the requirements for strai8hcening.

__ -:o ___ weJ.ding...-.and ... heat •. t r.e.atrAent. of .manganese.- bronze, nick.el.-m.anganese bronze t n1ck.el aluminum bronze and manganese-nickel-aluminum bronze propellers used on Naval ships.

1.2 Approval. Facilities 'intending to repair bronze propellers for the U.S. Navy, 1n accordance with this standard. must have prior Naval Sea Systems Command (NAVSEA) approval of their tec.hnical ability for compliance. This approval shall be a part of their contract and may inelude documentation review or facility audits.

2. REFERENCED DOCUMENTS

2.1 Government documents.

2.1.1 S~ecification8 and standards. unless otherwise specified, the following specifications and standards of the issue listed in that issue of the Department of Defense Index of Specifications and Standards (DoDISS) specified in the solicitation form a part of this standard to the extenc specified herein.

SPECIFICATIONS

FEDERAL

QQ-C-390

MILITARY

- Copper Alloy Castings (Including Cast Bar).

HIL-E-278 - Electrodes. Welding. Covered, Aluminum Bronze.

STANDARD

MIL-E-23765/3 - Electrodes and Rods - Welding. Baret Solid COpper Alloy, HIL-a-24480 - Bronze. Nickel-Aluminum (UNS No. C95800) Castings For Seawater Service.

HILITARY

HIL-STD-248 - Welding and Brazing Procedure and Performance

Qualification, KIL-STD-271

HIL-STD-278

- Nondestructive Testing Requirements for Metals.

- Fabrication Weldlag and Inspection; and ca8ti~

Inspectioa and Repair for Machinery, Piping and Pressure Vessels in Ships of the United States Navy.

2.1.2 Othet Government publications, The following other Government publications form a part of this standard to the extent specified herein. r.

PUBLICATIONS

28 October 1986

NAVAL SEA SYSTEMS OOKHAND (NAVSEA)

090o-LP-003-8000 - Ketals, Surface lnspeetion Acceptance Standards.

0944-LP-007-4010 - Karina P~opellers.

(COpies of speCifications, standards, and publleatlona required by con tractors in connection w1th specific acquisition functions should be obtained from the contracting activity or 8S dlrect~d by the contracting officer.)

2.2 Other publications. The following documents form a part of this stan dard to the ext~nt specified herein. Unlees otherwise specified. the issues of the documents which are DoD adopted shall be tbose listed in the issue of the OODISS specified in the solicitation. The issues of documents whtch have not been adopted shall be those in effect on the date of the cited DoDISS.

AMERICAN BUR.IWJ OF SHIPPING (ABS)

Guidance Manual for Bronze and Stainless Steel Propeller casting.

(Application for copies should be 8dd~e88ed to the American Bureau of Shipping, 65 Broadway, New York, NY 10006.)

AMERICAN WELDING SOCIETY (AWS)

A2.4 - Symbols for Welding and Nondestructive Testing

Ineluding Brazing. (DoD adopted) AJ.O - Standard Welding Te~ and Definitions Ineluding

Terms For Brazing, Soldering .. thermal Spraying II and ,'naermal Cutting. (DoD adopted)

AS.7 - Specification for Copper and COpper Alloy Bare Welding Rods and Electrodes. (DoD adopted)

AS.27 - Specification for Copper and Copper Alloy Rods for Oxyfuel Gas Welding.

B~.O - Standard Methods for Mechanical Testing of Welds.

(DoD adopted)

(Application for eo pies shQuld be add~es8ed to the American Welding Society, Inc •• SSO NW LeJeune Road. p.O. Box 351040. Htam1. FL 33135.)

(NongQvernment standards are generally available for reference from libraries. They are also distributed among nongovernment standards bodies and using Federal a.gencies.)

2.3 ~der of precedence. In the event of a conflict between the text of this standard and the reference8 cited herein, the text of thle standard shall tak.e precedence.

3. DEPINITIONS

3.1 General,. Except as noted .. hereio •. ve..l~'pg D9Uleflclature an4 definl.!:,!O.~8" shall conform c·o rAWS A2.4 and AWS AJ.O·.

3.2 Definitions. Tbe following definitions are applicable to this standard:

(a)

(b)

(c)

(d)

Acceptable. Acceptable sball mean complIes with or confo~s to the applicable standard or specification. £

Activitl- An activity Is the physical plant of 00 organl~8tlon performing work in accordance with 8 contract specification which references this document.

Approved (approval). Approved (or approval) shall mean that the item under consideration has been approved by NAVSEA or its authorized representative. Unless otherwise specified.

approval or approved as used hereIn shall be by the authorized representative.

NAVSEA 8uthorize~ rep~esentative. The NAVSEA authorized repre sentative shall be the Government representative specIfIcally authorized to approve equipment, materials, or procedures within the seope of this standard for NAVSEA and who is listed as follows:

(1) Naval Shipyard Commanders.

(2) Supervisors of Shipbuilding (SUPSHIP).

(3) Commanding Officer, Naval Ship Systems

Engineering Station (NAVSSES).

(4) Naval Ship Repair Facilities Commanders.

(5) Delegated representatives of these authorities.

(6) Representatives specIfically authorized by NAVSEA on a case by case basis.

(e) Cavitation erosion. Cavitation erosion is erosion resulting from the rapid formation and collapse of water vapor bubbles aD metal surfaces during high relative motion of the propeller whieh results in a porous, spongy. and pitted metal surface.

Metal surface areas with heavily concentrated porosity. and concentrated porosity associated with cavitated eroded areas, are to be interpreted and treated aa part of the cavitation erosion effect.

(f) Propeller definitions.

(1) Pressure face. The pressure or aft face of the propeller blade Is the blade surface that is usually adjacent to the aft end of the hub •. The aft end of the hub i8 readily identified by the small end of the taper bore and reduced hub outside diameter.

(2) Suction face. The suction or forward foce (sometimes referred to as the back) 1s the blade surface that is usually adjacent to the forward end of the hub. The forward end of the hub 1$ readily identified by the large end of the taper bo~e. a large hub outside dia meter and in g08t CAses 0 bore recess in the forward face to recelve·the shaft sleeve. gland ring, and seal.

J

(l) Leading edJl~. The leading edge of a propeller blade is the blade edge adjacent to the forward end of the hub.

Thie applies to both right hand and left hand propellers.

The leading edge thickness is relatively heQvy when compared with the thinner trailing edge.

(4) Trailing edse. The traIling-edge of the propeller blade is that which is adjacent to the aft end of the hub.

This applies to both right and left hand propellers. The trailing edge is the thin edge when compared to the leading edge.

(8) Minor repair definitions.

(1) Minor bends. Hinor bends are those near the blade tip, norm ally not farther from the edge than one-tenth of the blade section length, or bends outside the 0.95 radius (R). Minor bends should be limited to blade sections under 1-1/4 inches thick and with 8 corrected defleecion of leSB than 15 degrees.

(2) Hinor cracks. Hinor crocks are those located within 2 inches of the blade edges and with lengths less than 2 inches. In addition. 8urf8c~ craeks and cracks not exceeding lIS-Inch 1n depth or one quarter of the locol thickness, ~~ichever Is less, and not greater than 2 inches 1n length shall be defined as minor.

(3) Hinor patches. Hinor patches are those patches applied co 8 blade where a small portion of the blade edge is missing (not over 2 square inches) and repairs may be made entirely by added veld metal.

(4) Hinor cavitation erosion. Weld repair of cavitated OT eroded areas less than 2 square inches in surface area and which are less than 1/2-inch deep.

(b) Maior repair definitions.

(1)

(2)

(3)

(4)

HaJor bends. Major bends are those greater chan listed in 3.2(8)(15 and may involve bending 1n a forward or aft direction across the entire blade section.

Hsjor,c£aeks. Hajor craeks are those greater than listed 1n 3.2(g){2).

Major patches_ Major patches are those greater than listed in 3.2(g)(3), or those ~equlrln8 the use of a sepsTately cast or forged patch piece welded to replace a missing seccion.

Major cavitation eroslon~ Kajor cav1taclon erosion is that which exceeds the limit as specified in 3.2(g)(4).

(1) ~eldl!S proce~ures. Welding procedures are WTitten instructiona deSigned for use in production welding and repair welding.

delineating the essential elements and providing guldan~e to

/ produce reliable welds.

0.

OOD-STD-218S(SH)

28 October 1986

(j) Propeller classifications.

(1) Class 1, hiah precision. Class I propellers are those propellers normally associated with combatant or other high , perfo~Dce sbips or craft. The noise critical type and non-noise critical type are within this classification.

Propelle~ blade sectioD and edge and tip gauges are no~lly required for repairs to these propellers. .

(2) Class lIt mode~a!e pre~1s1on. Class II propellers are normally associated with amphibious) awc.111ary, and non combatant ships. Propeller blade gauges mayor may not be required for manufacture, but the drawing tolerances are generally in agreemenc with the requlre~ents for non combatant ship propellers.

(3) Class lIlt low preci~lon. Class III propellers ore those propellers for service eraft, small boats and similar applications.

4. GENERAL REQUlREHENTS

4.1 ReSponsibility. Each activity that accomplishes work in accordance with this standard ahall be familiar with its provisions and reference specifi cations to the extent that these provisions apply to the work being performed.

Also, each activity shall be:

(8) Capable of welding, straightening and heat treatment of ship pro pellers- Where services of outside suppliers are utilized, the activity Is responsible for assuring that the process is performed in ac~ordance with the requirements of this specification.

(b) Responsible for the quality of workmanship and maintenance of con trols and records necessary to ensure reliability and integrity of the finished propeller.

(c) Responsible for preparation of process procedures specified herein.

in~ludlng ~onductlng welding qualification tests; and maintaining qualification recorda in accordance with HIL-STD-248 and this standard.

(d) Responsible for the proficiency of personnel Bnd equipment to ensure conformance to the design and apeeif1eation requirements.

4 .2 .9!:!.allty aS8uro.nce.

4.2.1 Gene~al. This section contains the minimum requirements for assuring that repaired propellers meet the inspection criteria specified in this standard.

4.2.2 quality assurance system. Each activity shall maintain an inspection system adequate to Bssure NAVSEA or its autnori&ed repreaentative that all of the requirements of this standard have been and are continuously being met. Written procedures shall be prepared to s8s!gn responsibility and provide accountability for performing work and inspection.

4.2.3 Records.

OOD-STD-218S(Sn) 28 October 1986

4.2.).1 General, When specified in the contract or order, the quality control system ahall be prepared for each repaired propeller (see 6.2);

4.2.3.2 Record form. A record fo~ shall be prepared prior to the co~encement of the operation which it covers. Operations shall be recorded prior to the commencement of the next operation. Each operation on the record form shall be signed by the orgoniz8tlonts cognizant supervisor end dated.

When a specific item On the record form is not applicable, the 1~tter8 NN.A.

(not applicable) shall be entered. Final acceptance of a propeller repair shall not be granted until all items on the record forms are prepared and completed a8 specified in 4.2.3.1. ,.

4.2.4 ~ncomplinnce. If NAVSEA or its authorized representative has eVi dence that the requirements of this standard are not being met, he may provide written notification that the use of any questionable materials. equipment, procedures, personnel, and 80 forth is suspended. until compliance with the requirements of thiS standard 1s judged satisfactory.

4.) Weldins qualifieatlons.

4.3.1 Welding procedure q~alificat~on. When specified in the contract or order. prior to produetion welding, written welding procedures certified by the activity as containing the eSSential elements specified in HIL-STD-248 shall be prepared (see 6.2). The welding pro~edure ehall be qualified in accordance with HIL-STD-248 except that!

(a) The lover material thickness limit for test plate thickness quali fied does not apply to propeller repair. No lOWer limit exists.

(b) For procedures qualified on teSt plate thickness less than 1-1/2 inches, th~ upper thickness l1mit for productiOn welding shall be two times the test plate thickness; hovever, for procedure qualified on test plate thickness 1-1/2 inches or greater, the procedure Is qualified for all thicknesses.

(e) The qualification test 8ssembly sball be of sufficient s1ze to permit removal and testing of two transverse tensile specimens (see AWS 84.0), four side bend specimens (see AWS 84.0) and two transverse macrospee1mens. The acceptanee c~1ter1a shall be 1n accordance With HIL-STD-248 exeept that the tensile SpeCi~DS shall meet th~ strength requirements of table 1 herein for the material qualified. Bend specimen failure may not necessarily disqualify a veld procedure. Bend spectmen failure shall be reported to NAVSEA for consideration.

(d) Arc weld procedures qualified with 8 600 degrees Fahrenheit (OF) preheat qualify for repair welding at a minimum of JOO·p preheat.

DOU-STD-218S(SU)

TABLE I. Welding procedure qualification tensile requirements.

Type of propeller Tensile strength (alloy) Welding process Lb/1n2 udn1mum

Manganese (Hn) bronze Oxyfuel 40,000

Manganese (Hn) bronze All are processes 55.000

Nlckel-mangancae (NIKn) bronz.e OXyfuel 4S,OQO

N1ckel-manganeae (NiMh) bronze All ate processes 60,000

Nickel-aluminum (NiAl) bronze All art. processes 72,000

Manganese-niekel-nlumlnum All arc: processes 80,000 (HnNiAl) brooJ;e

4.].2 Welding procedure and qualification approval. The qualification test data shall be submitted to the authorized agent. a8 defined in accordance with HlL-STD-248~ for approval. When apeclfied in the contract or order, the welding procedure shall also be submitted for review and concurrence when qualification test data are submitted or whenever the welding procedure Is prepared (see 6.2).

4.).3 Altern~te pr~cess. Welding processes, procedures and materials, other than those specified in this standard. cay be used on the basis of procedure qualification teats for applications approved by NAVSEA or its authorized representative.

4.3.4 Proeedu~e regulre~~nt. Qualification tests shall be made at each activity wbere it Ie intended to repair bronze propellers. Exceptions (a) end

(b) below are to be detailed in the appropriate qualIty assurance system and demonstrated as controllable during prebid audit.

(a) The Navs! Ship Repair Facllities and Intermediate Maintenance Activities may use weld1ng procedures qualified by U.S. Naval Sh:1.p1a l'ds.

(b) The welding procedures qualified by a commercial establishment may be u8ed by any of its facilities as 10Dg a8 procedural controls are managed by a single entity of the establishment.

4.3.5 Welder performance gualification. The weIdel' who qualified the procedu~e 1s qualified for production welding. Additional veldera shall be requIred to qualify. and their qualification records maintained in accordance with HIL-STD-248. For bead specimen review, Bee 4.J.l(c).

4.3.6 Welding equipment. All manual. 8emi-auto~tict or automatic welding equipment shall, iD)the handa of a qualified velder or welding operator, consis tently produce 8atisfactory welds under production eonditions.

DOD-SrD-218S( SH)

4.4 Atmosphere exposure. Manganese bronze or nickel-manganeae bronze propellers are co be protected from prolonged e.pasure to industrial atmospheres (ammonia gases or solvents). The cycle of repair for these propellers shall be controlled eo as to minimize such exposure. NAVSEA viII consider temporary coatings to act as a barrler to industrial atmospheres. COntrol of exposure time will minimize the pOtential for stress corrosion craCking.

5. DEtAILED REQUIR.F..MENTS

S.J Materials.

5.1.1 Materials for repair. Propeller material and welding filler metal combination shall be 1n 4ccord~nce with table II. Propeller base material and welding filler metal shall conform to the following specifications:

(a) Propeller material:

Manganese broDze - alloy 865 in accordance with QQ-C-390 N1ckel-manganese bronze - alloy 868 in accordance wtth QQ-C-390 Nickel-aluminum bronze - alloy 1 in aecordance with HIL-B-244S0 Manganese-nickel-aluminum bron~e - KIL-B-24480

(b) Welding filler metal:

HIL-!-CuAl-A In 4ceordanee with HIL-E-278 EROuAI-Al tn accordance with AWS AS.' RCuZn-8 in accordance with AWS AS.27 RCuZn-C 1n accordance with AWS AS.27 HIL-CuAl-A2 in accordance with HIL-E-2316S/l HlL-CuN1Al 1n accordance with KIL-E-2376S/3 HIL-OuHnN1Al in accordance with HIL-E-2376S/3 NIHn bronze strips

\D

TABLE II. Welding processes and filler metals.

PlIler meta.l

Alloy type l! Welding process Type Croup 11 Classlfieation ~ Speclfieatlon

Hn broDze Shielded metal ere (SMA) AI bronze A-37A HIL-E-CuAl-A HIL-E-278 S .. l7A Gas metal arc (CHA) Al bron~e A-36B HIL-CuAl-A2 HIL-E-2J76S/l

Gaa tungsten arc (CTA) AI bronze A-36B EROJAl-A2 AWS AS.7 Oxyfuel Low fuming brass A-358 ROlZn-B ASiS AS.27

RCuZn-C AWS AS.27

N1Kn bronze Shielded metal arc (SMA) Al bronze A-37A HIL-E-CuAl-A HIL-E-278 S-378 ~s metal are (CKA) Al bronze A-36B KIL-CuAl-A2 HIL-E-2376S/J

Gas tungsten arc (CTA) AI bronze A-36B ERCuAl-A2 AVS AS.7 Gas tungsten arc (GTA) Sa~ as propeller NA NA NA Oxyfuel or bot flow Same as propeller NA NA NA .

HiA1 bronze Shielded metal arc (SMA) Al bronze A-37 A HIL-E-CuAl-A H1L-E-278 S-36A Cas metal arc (GHA) RiAl bronze A-37B HIL-CuNiAJll MIL-E-2376S/J

Gas tungsten are (eTA) IUAl bronze A-378 HIL-CuNicll HIL-E-23165/3

HnNiAl Shielded metal a~c (SMA) AI bronze A-37A HIL-E-CuAl-A HIL-E-278 bronze Cas metal arc (GMA) HnNIA1 bronze A-37B HIL-CuKnNIAI HIL-E-23165/l S-J6B Gas tungsten a~c (GTA) MaNiA! bronze A-37B KIL-CuHnNiAl KIL-E-23765/l

1/ The "8· and ·A~ designations for alloy type and filler metal group refer to desIgnations 1n accordance

- with tables I and It of KIL-STD-278.

2/ Equivalent AWS electrodes may be used, subject to acceptance by the government representative.

11 HIL-CuAl-A2 may be substituted with NAVSEA approval.

I

I

NC

(1)0

01' n fJ) M'O-;

g.y ~ N

" co - "" ~CX)ttJ 0'\ :::: -

OOD-STD-218S(SH)

5.1.2 Material substitution approval. Unless otherwise specified 1n the Government specifications, material acquired 1n accordance with AWS. ASTH, ABS or ASHE standards (or approved substitution material list) may be used for materials as speeified in 5.1.1 8ubje~t to approval by NAVSEA or its authorized representative.

5.1.3 Specification deviations. Unless otherwise specified in the appli cable contract or specification. deviations from the requirements of governing material specifications must be approved by the contracting agent as concurred with by NAVSEA.

5.1.4 Propeller materia! identification. 00 most propellers, material identification is stamped on the hub. Haterial determination shall be performed prior to any repair operation in the following cases:

(a) When the material identification stamped on the hub has been obliterated.

(b) When the propeller material Is manganese bronze or nickel manganese bronze and repairs by welding are anticipated.

(c) When there is reason to believe the scamped hub data 1s inacc.urate.

(d) At the request of the NAVSEA representative.

5.1.5 Zinc egu1valent and alpha/beta determ1natio~.

5.1.5.1 Zlns~guiv81ent. The amount of aluminum and the 'inc equivalent eKert a major influence on the weldabl11ty of manganese bronze and nlckel manganese bronze. Values of zinc equivalent less tban 45 percent. calculated 4S follows. are indicative of a material chemistry that may be suitable for welding:

Percent zinc equivalent - 100 - (100 X eerce~t copper) (100 + A)

Where A is the algebraiC sum of the follovlng zinc replacement factors:

Tin (So) a + 1 X percent Sn Aluminum (Al) • + 5 X percent At Manganese (HIl) ell -0.5 X perc.ent MIl Iron (Fe) - -0.1 X percent Fe Lead (Pb) - 0.0 Nickel (Hi) G -2.3 X percent Nt Silicon (st)J1 a + 9.0 X percent S1

!f Only that portion of the silicon which 1s in solid 8olution can be counted for zinc replacement. Normal chemical analYSis includes the silicon which 1s present as allica or silicates; rarely will more than half of this total amount be present 8& silicon 1n solid solution.

OOo-STD-2185( SH)

5-1.5.1.1 Zinc equivalent re9ui~ement. A determinacion of zine equivalent is required for manganese and niekel-manganese bron~e propeller.

5.1.5.1.2 Zinc egulvalent sampling plan. For manganese and nickel-manganese bronze propellers, one ~inc equivalent check shall be taken from each blank, or renewal seetion of blank to be repaired. The sample shall be taken in reasonable proximity to the repair. Only one sample 16 required for each blank or section.

If zinc equivalent is greate~ than 45 percent. request guidance from NAVS!A.

5.1.5.2 Alpha/beta determination. When the alpha phase content of 6 manganese bronze or nlekel-manganese bronze specimen taken from an area which is to be repaired by welding, or from tbe end of the acceptance cest bar, ls deter mined by microscope measurement to be~20 percent or more, this 18 indicative of material good weldabl11ty.

5.1.5.2.1 Alpha/beta requirement. Alpha/beta determination 1s required for manganese and nlekel-manganese bronze propellers.

5.1.5.2.2 Alpha check sampling plan. For manganese bronze and nickel manganese bronze propellers, one alpha check shall be taken from each blade, or reneval sectIon of blade, prior to vold repair. the sample ehall be taken 1n base material at a reasonable proximity to the repair. The sample shall be taken in the vicinity of the &lnc equivalent check. Only one sample may be required for each blade or Section In the case of mUltiple repairs per blade or section.

If alpha 18 les& than to percent, NAVSEA guidance sball be required. The recommended method for alpha check shall be the replica technique (see 5.1.5.2.3), although regular metallographic s8U1pllnS may be used. After veld repair and after strese relief, an alpha check shall be taken 1n the vicinity of one weld and in one 3 to 6 lnch resion from that one weld per propeller. It shall be taken in the vicinity of the test prior to welding. Results shall be reported to NAVSEA'in accordance with the data ordering document included in the contract or order (see 6.2).

5.1.5.2.3 ReElies te~hnique for determination of alpha/beta content. The replica technique (or plastic imprint method) Is a step-by-step documentacion procedure of the method 8S developed by Hr. Y. Umezu of Yokosuka Naval Ship Repair Pac111ty. It is used to determine the alpha/beta composition.

(8) Preparation of the blade shall be as follovs:

(I) Rougb grind the regions to be tested to ensure 8 flat surfaee at the area to be sampled. .

(2) Poliah the surfaee of the test regions with a 64 grit sanding paper. Then sand with successively finer grit papers (240, 360, 400. and flnally 600 grit) rotating the dlreetion of eandlog 90 degrees with respect to the direction used vith tbe preced1Q8 grit paper, and continue with one grit until all marks of the previous larger grit are removed.

(3) Prepare 8 poll,bing paste by adding vater to 8 chr~e oxide powder. Apply witb a felt cloth and finish poli8h the three

" surface areas. wrapping the cloth over a wooden paddle may be useful in maintaining an even pressure during polishing.

DOD-STD-2l85(SH)

(b) Etching shall be as follows:

(1) Using a 7X loupe (or higher magnification). locate regions within the poliehed area which have minimal scratches. It is recommended that two samples be taken from each area.

(2) Etch areas with nitric acid leaving the acid on the surface only 2 or 3 seconds followed by 8 water rinse e.aeh time.

Etch the area three or four times, oh8erving the etched region after each rinse. Once the areas are 8uffielently etched, finish rinse with acetone and alr dry.

(e) Plastic imprinting shall be as fOllows:

(1) Apply acetone to one side of a pi~ce of plastic (approxi mately 3/4 by 3/4 by 1/16 inch) wetting it for about 30 seconds. Place pl~8t1e. acetone side down, on the blade surface and ~re8S down approximately 30 seconds. Leave in place for 15 to 20 ~inute8. Carefully re~ove the specimens by prying up an edge and place tbe specimens in indivtdually marked bags.

(d) The Plastic replica 1s placed on the metallograph stage and a mirror 1s placed above it to increase the contrast in the image.

(e) Ie 1s recommended that only one area be etched at a time as the polished area will continue to corrode even after the acetone rinse ..

(f) Alpha/Beta content shall be dete~1ned by scandard metallographlc techniques.

5.2 Proeeller handlina.

5.2.1 General. The haQdling~ lifting. and turning of propellers shall be in accordance with NAVS!A 0944-LP-QQ7-4010.

S .. 3 Welding ..

5.3.1 Welding prerequisite. Prior to performing any repair weldirtg on bronze propellers covered by thiG standard. the welding procedur~ And welding operator shall be qualified 1n accordance with HIL-STD-248 artd 88 specified 1n

4.3.1. 4.3.2, 4.3.3, 4.3.4, and 4.3.5.

5 .. 3.2 Preheat. The pr~heat temperature rsnges for the various welding pro~esaea and propeller allOys shall conform to table Ill. The preheat tempera ture shall be ~asured in tbe area to be welded and Od the opposite side of tbe blade. The difference in temperature between both sides of che blade shall not exceed 506 r. The preheat temperature shall extend 12 lnchee in all direct10ns from the repair area 80 that a maximum temperature gradient of about 100·' per foot can easl1y be maintained in the surrounding area. Soft ga8 torches (soft neutral or sligbtly reducing flame) or ele~tric81 resistance (strip) heaters are recommeDded for preheatins rather thaD oxyacetylene torches. and the temper ature should be cheeked at frequent intervals by meaDS of temperature indieating crayons or contact pyrometers. the preheat temperatuTe ahall be Q81ntelned tb~ougbout the entire welding operation. Adequate support for the propeller shall be provided during the preheat and welding operations.

t 5.3.3 Welding requirements- The processes. filler metal types, and heating proeedures for the repair of bronte propellers shell conform to tables II and III for the alloy type indicated. SKA. CHA and CTA welding processes are satisfactory for all major and minor repairs on all types of propellers. Oxyfuel gas welding is permitted on mangaDese bronze and nickel-maosanese bronze propellers, but it shall be limited to the repair of edges on the outer one-third of the propeller radius and in general to sections under 1-1/4 inches thick. The welding opera tion on manganese-nickel-aluminum b~onze propellers shall be performed as expedi tioualy aa possible to aVOid prolonged heating at the adjacent area, which may cause embrittlement.

TABLE Ill. Weldiea processes and heatipa requirementse

Alloy Preheat Stress relief type Welding process temp (Or) temp "Car)

Hn bronze Shielded metal arc (SMA) lIY 6/725-825 and Gas metal arc (CHA) lIY 6/725-825

NiHn Gas tungsten arc (GTA) J/ 1;/ !l725-825 bronze

Oxyfuel 600-800 !!725-825

HiM Shielded metal arc (SMA) 60 Min!! None bronze

Gas metal arc (CKA) 60 H1n.!1 None

Gas tungsten arc (CIA) 60 Min!! None

KuNiAl Shielded. metal arc (SMA) 3/4/100-300 5/1050-1150 bronze

1/4/100-300 111050-1150 GaB metal orc (GHA)

Gas tungsten arc (etA) 3/4/ 100-300 ~/ 1050-1150

11 A 600 to SOOop preheat shall be required within a I-foot band a~ound the propeller blade outside of the 0.7 radius. The other area will require 8 3000 p preheat.

2/ Cool slowly after welding by wrappfns with insulating blankets_ 3/ Cool in Btill air after welding_ 4/ Interpass temperature 400·' maximum.

5/ Minor repairs, 89 defined 1n 3.2(8) and velds of prairie air channel cover plates need not be stress relieved.

1/ Furnace Btress relief 8S defined 1n 5.5.2.1 18 the only acceptable method •

DOo-STD-218S(SH)

5.3.4 Repairs to critical areas. No welding in way of the critical area of a blade is to be undertaken without prior approval by NAVSEA or authorized rep~esent8tive. As shown on figure 1. the critical area 1s defined 8& the a~e8 In the pressure face of the blade betveen the fillet and O.4R and startiog at the leading edge encompassing 80 percent of the cho~d length taken at 0.4R.

Repairs in these areas shall be ~ade by means of arc welding when approved.

5.3.5 Joint deaiK9. and position. Repairable defects sball be a1r-carbon arced, chipped, or ground to sound metal, and recommended grooves (see figures 2 and 3) provided for velding in the flat (down hand) position.

5.3.6 Peening. All layers of weld metal may be peened to help control distortion or relieve stresses. Adequate propeller support shall be used when peening.of the first layer is performed. Peening of the last layer is permitted provided this layer 1s subsequently ground to remOve all evidence of peening prior to visual and liquid penetrant inspection.

5.3.7 Repair exceptions. The repair of defects by meaas of 80ft solders or silver-brazing alloys shall not be permitted.

5.3.7.1 Small defects. Repair of small defects for sake of appearance shall be avoided. Cavities with 8 maximum depth of l/8-inch shall be left undisturbed (see S.).8).

5.3.8 Weld repair inspection. All welds shall be visually inspected after weld repair and before stress relief (if stress relief is required). Visual inspection 1s sgain required after stress relief. Liquid penetrant lnspeetion.

1n accordance with HtL-STD-271. shall be performed as an aid to visual inspection in locating discontinuities. D1scontinuities located by liquid penetrant inspec tion shall be evaluated for repair based on actual size of the discontinuity and not on the indication size developed during the liqutd penetrant inspection.

Weld repairs shall be evaluated io accordance with table I of NAVSEA 0900-Lp-oOl-8000 with the following exceptions:

(a) Combatant noise critical eropellers. Surface porOSity shall be limited to 0.010 inch in size 1n a 1 loch vide band on each face along the leading edge. and at the break of the knuckle along the trailing edge.

(b) All propellers. A propeller will be considered acceptable even thouSh it exceeds the limits specified 1n table I of NAVSEA 090o-LP-003-8000 under the following conditions:

(1) Service and subsequent inspection has confirmed that there are no cracks in the affected area. This may be in the original casting or prevlou~ veld repair areas.

(2) Provided no actual cracks are detected. existing linear indications outside the weld repair area are acceptable.

(c.) S.3'.8(a) takes precedence over S.l.8(b).

S.4 Straightening.

DOD-ST'D-2185(SH)

28 October 1986

5.4.1 ~n!tal. The appropriate straightening procedures given In table IV shall be followed in Gaking repairs to the types of propeller alloys listed.

5.4.2 Cold 8~rai8hten1ng. Cold straightening (temperature belov 400·P) by meSDS of dynamic loads ahall be used only to repair minor bends. The straight ening operation, 1n the case of m8Qg8nese broDze~ nickel-manganeae bronze and manganeae-nickel-aluminum bronze propellers, shall be followed by a suitable stress relief treatment in accordance with table tv and S.S.l througb 5.5.4.

TABLE IV. Heating requirements for straightening-

Loading!/ Straightening Stre8s relief Alloy type Type of repair tl\ethod telSlp ., temp .p

Hn bronze Kinor Dynamic or 400 me.xJj 8/725-825 slowly applied

NUtn Hinor Dynamic or 400 msxY 8/725-825 bronze &10wly applied

NlAl Hioor DynamIc or 400llUlx None bronze slowly applied

:!:/~./!/140o-1650 Major or minor Dynamic or None slowly applied

MnNiAl Very minor only Dynamic or 400 DUlle: 31 3/4/1050-1150 bronze slowly applIed

1/6/1/1450-1550 1/4/ 1050-1150 Major ot minor Dynamic Or slowly applied 3/4/10S0-1150

11 A dynamic load 1s one which 18 moving prior to contact with the propeller.

A slowly applied load 18 in constant contact with the propeller when 8tress 1s applied.

2/ Cool slowly after straightening- 3/ Cool 1n 8till air after straighten1ng and stress relief operation.

4/ Hinor repairs as defined in 3.2(8) need not be stress relieved.

5/ Temperature must be reached and maintained during the complete straightening operation.

~ In order to obtain B temperature within the 1400 to 16S0°F range the follow ing heat1ng controls are recommended.

(a) Hest with propane torcbes faT Qot less than 3 hours.

(b) Heat should be applied over a large area and should extend

J-l/2 feet beyond the bend area.

(e) Oxyacetylene torches should be used to implement heating for straightening.

l! A generous area in which straightening 1s to be done 1s to be heat soaked prior to applying load. .

8/ Purnace stress relief 4S defined in 5.5.2.1 1s the only acceptable method.

000-51'0-2 Id5( SII)

5.4.3 Hot straightening- Hot straightening ~y only be applied 8S noted in table IV. The portion of the propeller which 1e being straigbtened should be kept within the recom=ended temperature range a9 specified in table IV during the course of the repair by means of soft gas torches (soft neutral or slightly reducing flame). supplemented when necessary with beat from moving oxyacetylene torches. A generous area surrounding the section to be straightened shall be heated tbrough its entire thickness to the required temperature. The required straightening temperature and stress relief requirements shall be 1n accordance with table IV snd 5.5.1 through S.5.4.

S.4.4 lnspe£!i~n after straightening. The straightening repairs shall be Visually inspected after straightening and then again after stress relief (If stress relief is required). Liquid penetrant inspection shall be performed a8 'SD aid to visual inspection in locating di6eont1nuit~es. The acceptance stan dards and exceptions shall be as specified 1n S.3.8.

5.5 Stress relief.

5.5.1 General. Welding or straightening repairs made on manganese bron~e, nickel-manganeae bron&e and manganese-alckel-aluminum bronze propellers shall be stress relieved within the appropriate temperature range shown in tables 11 and IV. Although the stress relieving treatment is ususlly carried out immedi ately after repairing, no harm 1s to be expected if the repaired area OD manga nese bronze or nickel-mart8aneee bronze 18 first allowed to cool slowly to room te~perature by wrapping in an asbestos free insulation blanket. The heating and cooling of manganese-nickel-aluminum bronze ahall be such as to avoid the 660 to 1050·' temperature range which may cause embrittlement. A stress relieving treatment should be given ss soon a8 practicable. A furnace stress relief 1s required for all weld repairs Bnd straightening operations on manganese bronze and nickel-mangsDese bronze base material. For manganese-nickel-aluminum bronze furnace stress relief 18 strongly recommended where repairs in heavy sections or fillet areas have been made. Manganese and nickel-manganese bron~e propellers being reconditioned that have been in service over 7 years or that have been 1n storage and cannot be certified as having been 9tress relieved at the time of reconditioning or prior to storage. to these requirements shall be furnace stress relieved. N1ckel-aluminum bronze propellers do not require the stress relief treatment.

5.5.1.1 Han anese-oickel-aluminum bronze Stress relievlng of

m8DBanese-oickel-aluminuc bronse (supers ton 40 propellers 1s required subsequent to straightening or weld repairs, except for the welds of prairie air channel cover plates and minor defects in noncritical areas (see S.3.4).

5.5.2 Furnace stress relief.

S.5.2.1 !urnace stre~6 relief of manganese bronze and nickel-mangaDese bronze. Furnace stress relief ahall be accomplished by slov uniform beating to a holding temperature of 725 to 82SoF. Application of heat shall be controlled

(a) 80 that the heating rate does not exceed SO·, per hour at soy thermocouple ~D the propeller; aDd (b) &0 that a temperature differential of lOO·P Is not exceeded among any of the attached thermocouples. Time at the holding tempera ture shall begin when all attached thermocouples are within SO·p of each other

OOD-STD-2 J 8!H SH)

28 October 1986

" and are within the 725 to 825·' range. This control (50·F maximum differential within the 125 to 825·P range) shall be maintained for a minimum of 12 hours prior to tbe start of cooldown. COoling shall be controlled (a) so that the coolIng rate does not exceed 500 y per hour at any thermocouple on the propellerj and (b) 80 that a temperature differential of SO·p 1s not e~ceeded among the attached (without welding) thermocouples. Control of coollng and the monitoring of temperatures shall continue until the maximum temperature of the thermocouples attached to the bub Is within 100·P of ambient air temperature outside the furnnce.

S.S.2.2 Furnace stress relief of man,anese-nickel-aluminum bronze. This method is recommended where possible and shall be accomplished by heating the entIre propeller in a furnace. Stress relief shall be effected by Blow uniform heating to a holding temperature 1n the stress relief temperature range as required by table lIar IV. The heating rate shall be controlled 80 that a temperature gradient of lOOoP is not exceeded among the thermocouples Bttacbed to the propeller for monitoring temperatures. In add1tion. the surface on which the propeller 18 placed shall be constructed in such a =anner to pe~t circulation of the hot gases through the propeller bore. Time at the holding temperature shall 8t~rt ~hen all attached the~oeouples read within a t~per8-ture differential of 100·F and are within the stress relieving range. This degree of control shall be maintained during the holding period for a minimum of 12 hours prior to the start of cooling. During the cooling cy~le. control of the temperature ,radiant shall be maintained 60 that the differential does not ezeeed 50·F. Monitoring of propeller temperature shall continue until hub temperatures are within 100·' of ambient air temperature outside the furnace.

5&5.2.3 TempeTa~ure record1!!_ A record of furnace air temperatures 6S veIl as propeller temperatureS shall be obtained during the stress relief be&t treatmen~ cyele at intervals not exceeding 1 hour. Propeller temperatures shall be monitored by thermocouples loeeted in the following positions:

(a) On the top face of the hub.

(b) On the bottom fsce of the hub.

(c) At the cen~er (mid-length) of the bore.

(d) On the outside center (mid-length) of the bub.

(e) At the center (O.6R and mJd-chord) of the pressure and suction faces of tva opposite blsdes.

(f) Within 1 inch of the tip at the centerline on the underside of all blades located to measure furnace ambient (air) temperature.

(g) Located to measure furnace ambient (air) temperature and furnace floor temperature.

5.S.2.3.1 ThermocouEle attachment. The~oeouple6 shall be attached ~o the propeller in such a manner that their removal will not result in damage to cbe attachment areas and tbey shall be insulated from the atmospheric temperature where veld1ng i& utilized in conjunct1on with manganese bronze or niekel manganese bronze appropriate inspection is to be made to ensure that no cracking has developed.

5.5.3 Local stress relief •

DOo-STD-2185(SH) 28 October 1986

. 5.SA3.1 General. Local stress relief may be performed when furnace stress relief Is not practical. or the scope of the weld repair is such that furnace stress relief is not required. Loeal 8tres8~elief may alao be performed if minor repairs are required after furnace stress relieving or when repairs (welding or straightening) have been partially accomplished but repair must be interrupted and set aside for 8 period of time. tn the latter case an interim loeal stress relief prior to furnace stress relief la recommended to minimize In-process cracking. Local stress relief Is not permitted on manganese bronze and nickel-manganese bronze.

5.5.3.2 Kajpr repairs. In order to effect a Bultable local stress relief, a band approximately 24 incbes wide and extending across the entire width and through the entire thickness of the blade shall be slowly heated to the stress relieving temperature $0 that a temperature gradient of 100°F per foot 1s not exceeded outside this band. The band shall be so located that the repair area is on the centerline of the band width and the heating shall be accomplished by means of 60ft gas torches (soft neutral slightly reducing flame) or electrical resistance (strip) heaters rather tban by oxyacetylene torches- The holding (soaking) time at temperature shall be at least 20 minutes per inch of base metal thicknes8 at the repaired area for manganese bronze or nickel-manganese bronze propellers. The holding time for maQgsoese-nickel-aluminum bronze propellers shall be no longer than what is necessary to meet the m1n~ 20 minutes per inch requirement. The repaired section of manganese bronze or nlekel-manganese bronze propellers shall be slowly cooled 80 that a temperature gradient of 500 y per hour is not exceeded. Slow coolIng from the stress relieving temperature Sh3ll be accomplished by wrapping or covering with insu lation blankets. The cooling of ~ngaDese-nickel-alum1num bronze shall be 1n still air at room temperature.

5.5.3.3 Minor repairs. For a local stress relief of minor repairs in areas subject to low working stresses, such 8S the blade edges and tips, the stress relief treatment shall consist of a gradual spreading and maintaining of the heat by…