The weldability and properties of joints welded in new-generation creep resistant steels: HCM12A steel

摘要

HCM12A (ASME T122) steel, containing 10-12 percent chromium and 2 percent tungsten, is made by the Japanese companies Sumitomo Metal Industries and Mitsubishi Heavy Industries, and is intended for fresh steam superheaters. The aim is to increase the resistance to corrosion at elevated temperatures over that of steels containing 9 percent chromium, e.g. P91, P92, and E911. This steel, a modification of HCM12 alloy, has a di-phase structure of tempered martensite and some 30 percent delta ferrite. The resistance to creep of HCM12 steel is higher than that of HCM12 alloy and is close to that of P92 material (see Fig. 8 in Ref. 7). Basic characteristics of HCM12A steel are quoted in an article published earlier. The present article contains results of investigations into the weldability of HCM12A steel and specifies the conditions of welding and the properties of obtained welded joints. This information is provided on the basis of both the available references and the experimentation carried out at the Welding Institute and the Boiler Making RAFAKO Co SA in Raciborz. Information about the performance of steel in the power industry is also provided.