If a weld is allowed to cool prior to the postweld heat treatment, the rate of uniform cooling must be controlled to prevent a detrimental effect in the piping.Partial heat treatment of a piping assembly that cannot be fitted completely into a furnace is acceptable if there is at least a 300 mm (1 f

At all stages of the heat treatment process, the temperature must be accurately monitored and recorded by a thermocouple or other suitable, approved method, to guarantee that the temperatures specified in the WPS are adhered to during the welding process. When necessary these temperatures must be re

Heat treatment is used to avoid or alleviate the detrimental effects of high temperatures, which are unavoidable during the welding process. The heat treatment required and the recommended temperatures and holding times vary among metals. They are specified in ASME B31.3, Table 331.1.1, Requirements

Heat treatment and product forms can have a profound effect on the degree of hydrogen embrittlement for certain types of superalloys with complex microstructures. In general, wrought superalloys, including the PM process, have been found to have a slightly less influence by high pressure hydrogen en

JBK-75 superalloy in solution annealed, with no aging, is negligibly embrittled by hydrogen at 34.5 MPa (5 ksi) pressure. Heat treatment study has shown that aging conditions would dramatically increase the US and UTS for JBK-75. However, such aging conditions would make JBK-75, including A-286 and

Because Inconel 718 has been used extensively for aerospace applications, detailed heat treatment studies were conducted by Walter and Chandler (ref. 16, 23) for rocket engine applications in a high pressure hydrogen environment. Table 17.8 presents the results of HEE Index for Inconel 718 in combin