Overview of the Specification:
Ordering Information
It is the purchaser’s responsibility to specify necessary information in the order to purchase the needed material. In addition to the ordering information guidelines in Specification A961/A961M, orders may include additional requirements.
General Requirements
Products should conform to the requirements of Specification A961/A961M, including any supplementary requirements that are indicated in the purchase order.
In case of conflict between the requirements of this specification and Specification A961/A961M, this specification should prevail.
Manufacture
The low-alloy ferritic steels should be made by the open-hearth, electric furnace, or basic-oxygen process with the option of separate degassing and refining processes in each case.
The stainless steels should be melted by one of the following processes: (a) electric-furnace (with the option of separate degassing and refining processes); (b) vacuum furnace; or (c) one of the former followed by vacuum or electroslag-consumable remelting.
The materials should be forged as close as possible to the specified shape and size.
Heat Treatment
After hot working, the forgings should be cooled to a temperature below 1000 °F (538 °C) and heat treatment is carried out.
Chemical Composition
A chemical heat analysis per specification A961/A961M should be done to determine whether the materials conform to the prescribed chemical composition.
Mechanical Properties
The materials should conform to the mechanical properties requirements for the grade ordered.
Retreatment
If the results of the mechanical tests do not conform to the requirements specified, the manufacturer may reheat the forgings and repeat the tests.
Nondestructive Test Requirements
Hollow forgings, whose internal surfaces are not accessible to magnetic particle or liquid penetrant examination, should be examined by an ultrasonic test. Hollow forgings, whose internal surfaces are accessible to magnetic particle or liquid penetrant examination, should be examined on their internal surfaces by either a magnetic particle test or by a liquid penetrant examination. An examination should be performed after all the mechanical processing and heat treatment.
Surface Finish, Appearance, and Corrosion Protection
Forgings and finished parts should conform to the requirements of Specification A961/A961M. They should be free of scale, machining burrs, and other imperfections defined here. The forgings and finished parts should have a workmanlike finish, and machined surfaces should have a surface finish not to exceed 250 AA roughness height.
Repair by Welding
Weld repairs should be allowed at the discretion of the manufacturer with the following limitations and requirements: The welding procedure and welders should be qualified. The weld metal should be deposited using the electrodes unless otherwise specified. Defects should be removed before welding by chipping or grinding to sound metal. The defects can be detected by magnetic-particle inspection or by liquid-penetrant inspection. After repair welding, the welded area should be smooth and free of defects. The preheat, interpass temperature, and post-weld heat treatment requirements must be met.
Inspection
Inspection should be done in accordance with the specification A961/A961M
Rejection and Rehearing
The purchaser should comply with the provisions of Specification A961/A961M.
Certification
In addition to the certification requirements of Specification A961/A961M, test reports should be provided to the purchaser. Test reports provide the following information: Type heat treatment, product analysis results, tensile property results, yield strength and tensile strength, elongation and reduction in area, chemical analysis results, hardness results, gain size results, and any supplementary testing required by the purchase order.
Product Marking
In addition to the marking requirements of Specification A961/A961M, the following additional marking requirements are followed: Quenched and tempered low alloy or martensitic stainless forgings should be stamped with the letters QT following the specification designation. Forgings repaired by welding should be marked with the letter “W” following the Specification designation. When repair-welded austenitic stainless steel forgings have not been post weld heat treated, the letters “WNS” should be marked. The markings should be painted or stenciled on the fitting or stamped on a metal or plastic tag. In addition, barcoding is acceptable as a supplemental identification method.
