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Work anticipated under this requirement consists of testing up to 312 casting coupons for the Fort Randall Major Unit Rehabilitation Project. The coupon material is ASTM A743 Grade CA6NM corrosion resistant stainless steel. An exception to the ASTM requirements is that carbon content shall not exceed 0.030%. The coupon is a rectangular as-cast block approximately 1-inch x 2-inch x 8-inch. On receipt of the coupon from the Government, the laboratory will process the blocks to produce the samples or specimens required for each test (chemical, hardness, tensile, impact). The coupons shall be processed such that as much of the original coupon as possible is preserved. The remnant that is not required for testing shall be packaged for storage with the tested specimens.

TESTING REQUIREMENTS

Requirements for Chemical Analysis:

Perform a chemical analysis according to the requirements of ASTM A751. Report chemical composition (percent) for the following elements: carbon, manganese, silicon, phosphorus, sulfur, chromium, nickel, copper, molybdenum, vanadium and tungsten. The carbon composition (percent) shall be verified using combustion method according to the requirements of ASTM E1019-11, Sections 10-20.The report shall include a comparison to the composition for each element as required by ASTM A743 Grade CA6NM, with the exception of carbon which is limited to 0.030%.

Requirements for Hardness Test:

Perform a hardness test according to the requirements of ASTM A370. Three readings shall be taken. Maximum permissible hardness shall be 285 BHN.

Requirements for Tension Test:

Perform a tension test according to the requirements of ASTM A370. The test specimen shall be machined to the form and dimensions of the standard round 2 inch gage length specimen as shown in Figures 4 and 5 of ASTM A370. Report the following: yield strength (MPa, psi is optional), tensile strength (MPa, psi is optional), elongation in 2 inches (percent), reduction of area (percent). The report shall include a comparison to the mechanical properties as required by ASTM A743 Grade CA6NM.

Requirements for Impact Test:

Perform a Charpy V-notch impact test on three specimens per coupon at 0°C in accordance with ASTM A370. The test specimen shall be machined in the form and

dimensions of the standard full-size specimen as shown in Figure 11 of ASTM A370. For each specimen, report absorbed energy in joules (J) and the average for the three specimens, also in joules (J). The report shall include a comparison to the following material requirements: absorbed energy greater than 54 J minimum for an individual specimen and greater than 61 J average at 0°C.

Metallographic Analysis:

Perform a metallographic analysis of the coupon. Provide a photo and short description of the microstructure present (i.e., tempered martensite, ferrite pools, etc.).

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