Scope_of_Work.pdf

SECTION C

DESCRIPTION / SPECIFICATION / WORK STATEMENT

C-1 REQUIREMENTS.

The Contractor shall furnish all labor, materials, services, equipment, facilities, etc., to fabricate, machine, heat-treat, test, inspect, pack, mark, and deliver the items listed in Section B (Supplies or Services and Prices/Costs) in accordance with these specifications and the following drawings:

DRAWING NUMBER ITEM DESCRIPTION

70006-4347-903 105 Shaft, Service Frame 70006-4347-903 106 Bushing, Service Frame 70006-4347-903 109 Shaft, Service Frame 70006-4347-903 110 Bushing, Service Frame 70006-4347-903 111 Bushing, Service Frame

70006-4411-919 004 Bushing, Overside Gimbal Ring 70006-4411-919 005 Bushing, Overside Support Frame/Pivot Arm 70006-4411-919 006 Shaft, Overside Gimbal Ring

70006-4558-909 116 Bushing, Center Draghead 70006-4558-909 607 Shaft, Center Draghead 70006-4558-909 608 Shaft, Center Draghead

70006-4418-912 203 Bushing, Centerwell Support Frame 70006-4418-912 232 Shaft, Center Gimbal Ring 70006-4418-912 233 Bushing, Center Gimbal Ring

70006-4013-907 204 Shaft, For Hopper Door Hinge (See C-2.4 below) 70006-4013-907 207 Bushing, For Bearing Pot (See C-2.4 below) 70006-4013-907 213 Bushing, For Hopper Door Pad Eye 70006-4013-904 402 Shaft, For Hopper Door Pad Eye 70006-4013-907 405 Bushing, Lower Push/Pull Rod w/Fork, Upper End 70006-4013-907 406 Bushing, Lower Push/Pull Rod w/Eye, Upper End 70006-4013-904 407 Shaft, Between Lower and Upper Rods

C-2 MATERIAL.

1. All shafts shall be made of “Astralloy-V” alloy steel (or equal). All shafts (with the exception of 70006-4013-907 -- item 204) shall be Re-normalized after machining (per section C-5, Heat-Treating of Astralloy-V bars – Normalizing Procedure) to obtain a through hardness of 420-470 Brinell. Care shall be taken during the heat treating in order to prevent scaling. After heat treating, all shaft outer diameters shall be smooth and finished to a maximum surface roughness of 125 RMS.

2. All bushings shall be made of “Astralloy-V” alloy steel (or equal). All bushings (with the exception of 70006-4013-907 -- item 207) shall be Re-normalized after machining (per section C-5, Heat-Treating of Astralloy-V bars – Normalizing Procedure) to obtain a through hardness of 420-470 Brinell. Care shall be taken during the heat treating in order to prevent scaling. After heat treating, all bushing inner and outer diameters shall be smooth and finished to a maximum surface roughness of

125 RMS.

3. Material salient characteristics for the “Astralloy-V” (after Re-normalizing) are as follows:

Material Description: High Strength alloy steel possessing the physical properties listed below.

Minimum Ultimate Tensile Strength: 190,000 psi Through Hardness: 420 – 470 HB (Brinell Hardness) Charpy V-notch Toughness: 27 – 45 ft-lbs Minimum Elongation (2 in., %): 11

4. Items 70006-4013-907 items 204 and 207 (shaft and bushing, respectively) shall be furnished in the annealed condition. The procedure for which is as follows:

Heat item to 1250 degrees Fahrenheit for 1 hour per inch of greatest thickness. Furnace cool item;

i.e., furnace is turned off and both furnace and steel are allowed to cool to room temperature at the same rate. Care shall be taken during the heat treating in order to prevent scaling. After heat treating, all bushing inner and outer diameters shall be smooth and finished to a maximum surface roughness of 125 RMS. All shaft outer diameters shall be smooth and finished to a maximum surface roughness of

125 RMS.

Material salient characteristics for the “Astralloy-V” (after Annealing) are as follows (physical properties):

Minimum Ultimate Tensile Strength: 135,000 psi Through Hardness: 240 – 300 HB (Brinell Hardness) Charpy V-notch Toughness: 27 – 45 ft-lbs Minimum Elongation (2 in., %): 18

5. Unless specified otherwise, tolerance on lengths for all items shall be + or – (plus or minus) 1/16 inch. Unless specified otherwise on drawings, tolerance on all diameters shall be + or – (plus or minus) 0.005 inch.

C-3 TEST REPORTS & INSPECTION.

The Contractor shall furnish certified analysis of chemical properties for all items furnished under this contract. Each test report shall be identified by Government Contract Number.

INSPECTION POINT. In the presence of the Government Inspector or contractor in-house quality control personnel (Note: the contractor can hire a qualified inspection company to perform the inspection; all cost for this service shall be included in the total cost of the contract) to verify dimensions, and compliance with these specifications and Contract drawings. The Contractor shall provide micrometer readings of shafts & bushings diameters and lengths. Note: Bushing diameters shall be verified prior to cutting slot.

C-4 DELIVERY.

The Contractor shall deliver the supplies to the Government Services Administration Warehouse located at 400 Edwards Ave., Bay B-1, Harahan, LA 70123. The Government will provide hoisting arrangement at the warehouse. The supplies shall be packed in protective crates with proper identification. Refer to Section D for packaging details.

C-5 ASTRALLOY WEAR TECHNOLOGY

Heat Treating of Astralloy-V ® Bars

Astralloy-V ® Bars are furnished in the normalized and tempered condition at 321 to 388 BHN. In order to achieve this hardness, the mills typically temper the bars near 800ºF to 1010ºF. If full hardness is required in a part, the parts should be renormalized.

It is preferable to turn the surface of the bars prior to normalizing in order to remove any seams that may be present. If seams are present, they could initiate cracking due to transformation stresses during the normalizing treatment. Removal of any seams can be readily verified by a visual inspection on a turned surface. Removal of approximately 2% of the diameter from each side is generally sufficient to ensure freedom from seams.

To minimize likelihood of cracking, especially in large diameters, the bars should be tempered at 400ºF, immediately after normalizing. The effect of the 400ºF temper on mechanical properties is minor, but it will lend to increase the yield strength and slightly decrease hardness. Some customers prefer to use Astralloy-V ® without the temper.

Normalizing Procedures

● Charge bars into furnace preheated to 1200ºF maximum.

● Equalize bars and then heat to 1650ºF (Controlled atmosphere may be used where scaling and decarburization must be held to a minimum).

● Equalize and hold at temperature for 30 minutes per inch of maximum thickness.

● Discharge from furnace and fan cool to 800ºF. (Do not stack parts or place directly on the ground.

Free circulation of air is essential).

● Turn off fans at 800ºF and allow to air cool to hand warm temperature, approximately 90 to 120ºF.

● To minimize likelihood of cracking, especially in large diameters, immediately recharge into a tempering furnace at 400ºF. Hold at one hour per inch of maximum thickness.

SECTION D

PRESERVATION/PACKAGING/PACKING

D-1 Packing. All items shall be packed in a manner in which will insure arrival at destination in a satisfactory condition and will be acceptable to the carrier at lowest rate. Packing shall comply with Freight Classification Rules or other carrier regulations as applicable to the mode of transportation. Surfaces requiring protection against abrasion shall be suitably protected.

D-2 Marking.

D-2.1 All parts must be clearly and permanently identified and marked with part number and applicability. Each small part shall be identified with a stamped metal tag securely wired thereto. The contractor can propose different methods of tagging or marking and submit to the government for approval.

D-2.2 All crates shall be clearly marked with stencil (1/4” high characters, minimum) with permanent ink or paint in at least two locations with the following information completed:

1. Item Name ___________________________

2. Contract No. _________________________

3. Dredge WHEELER.

4. Shipping Weight ______________________

D-3 Parts requiring preservation shall be coated with suitable anti-corrosion material.