【国外标准】 Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Tubing for General Service

This specification covers standard requirements for grades of nominal wall thickness, stainless steel tubing for services requiring general corrosion resistance, with particular emphasis on resistance to stress corrosion cracking. These steels are susceptible to embrittlement if used for prolonged periods at elevated temperatures. Heat and product analyses shall be performed wherein the steel shall conform to the required chemical composition for carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, nitrogen, copper, and others. All tubes shall be furnished in the heat-treated condition in accordance with the specified temperature and quench conditions. When the final heat treatment is in a continuous furnace, or when heat treated condition is obtained directly by quenching after hot forming, the number of tubes of the same size and from the same heat in a lot shall be determined from the prescribed sizes of the tubes. The material shall conform to the prescribed tensile and hardness properties. Mechanical tests such as tension test, flaring test (for seamless tubes), flange test (for welded tubes), hardness test, and reverse flattening test shall be performed on the steel tubing. Each tube shall also be subjected to the nondestructive electric test or the hydrostatic test.1.1 This specification2 covers grades of average wall thickness, or, if specified on the order, minimum wall thickness, of stainless steel tubing for services requiring general corrosion resistance, with particular emphasis on resistance to stress corrosion cracking. These steels are susceptible to embrittlement if used for prolonged periods at elevated temperatures.1.2 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. Within the text, the SI units are shown in brackets. The inch-pound units shall apply unless the M designation of this specification is specified in the order.1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.