9％-12％Cr高等级耐热钢的IV型开裂研究进展

Research progress on Type IV cracking of 9%～12%Cr high-grade heat-resisting steel

9%～12%Cr高等级耐热钢因其性能优势在超超临界机组中有良好的应用前景,但这些钢在高温、低应力长时间运行时其焊接接头的细晶区有出现IV型开裂的可能性。介绍国外研究机构对铁素体耐热钢IV型开裂的研究成果,分析了IV型开裂的试验应力该如何确定,我国目前投产运行的超超临界机组P92钢焊接接头的服役参数是否会导致IV型开裂从而引起部件失效等,从而为试验研究新型耐热钢的IV型开裂提供依据。

The 9%-12% Cr high-grade heat-resisting steel has bright application prospect in ultra supercritical power units for its remarkable performance. It is still possible for Type IV cracking to take place at the heat affected zone of weld joint after long-period, high-temperature and low-stress operation. The research results on Type IV cracking on ferrite heat-resisting steel of abroad institutes were introduced. Based on this, several problems were discussed, such as the methods to determine test stress of Type IV cracking, the operation parameters of P92 Steel weld joint for the ultra supercritical power units in operation, which leads to the failure of components. This provides great reference for the R＆D of new-type heat-resisting steel.