Реферат

This specification covers a group of common requirements that are mandatory for steel castings produced by the investment casting process for pressure-containing parts. Master heats shall be made by the electric furnace process with or without separate refining such as argon-oxygen-decarburization (AOD), vacuum-oxygen degassing (VOD), vacuum-induction-melting (VIM). Ferritic and martensitic steel shall be cooled after pouring to provide complete transformation of austenite prior to heat treatment to enhance mechanical properties. Chemical, heat, and product analyses shall be performed and the chemical composition thus determined shall conform to the prescribed values in carbon, manganese, silicon, phosphorus, sulfur, nickel, chromium, molybdenum, vanadium, tungsten, copper, and aluminum. Tensile testing shall be done on the castings and shall meet the required yield and tensile strength, elongation, and reduction of area. Each casting shall also be tested after machining to hydrostatic shell pressure test and shall not show any leaks.

Область применения

1.1 This specification covers a group of common requirements that are mandatory for steel castings produced by the investment casting process for pressure-containing parts under each of the following ASTM Specifications:

Title of Specification ASTM Designation Steel Castings, Carbon, Suitable for Fusion Welding, A 216/A 216M for High-Temperature Service Steel Castings, Martensitic Stainless and Alloy, for A 217/A 217M Pressure-Containing Parts, Suitable for High- Temperature Service Castings, Austenitic, Austenitic-Ferritic (Duplex), A 351/A 351M for Pressure-Containing Parts Steel Castings, Ferritic and Martensitic, for Pressure- A 352/A 352M Containing Parts, Suitable for Low-Temperature Service Steel Castings, Alloy, Specially Heat-Treated, for A 389/A 389M Pressure-Containing Parts, Suitable for High- Temperature Service Steel Castings Suitable for Pressure Service A 487/A 487M

1.2 This specification also covers a group of supplementary requirements, which may be applied to the above specifications as indicated therein. These requirements are provided for use when additional testing or inspection is desired and apply only when specified individually by the purchaser in the order.

1.3 When investment casting is ordered, the requirements of this specification shall take precedence over the individual material specification requirements.

1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.