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ASTM回火脆性研究小组指令各分公司执行了一项共同研究计划,这项计划主要确定NiCrMoV钢转子锻件采用介临界熟处理是否可以使整个锻件的各种性能都保持优异的平衡状态和具有改善其抗回火脆性的效果。其结果表明上述条件只对在脆性范围内工作的转子部件产生良好的作用,对在低温下工作的转子部件则并无效果。介临界热处理的锻件在399℃时几乎没有脆性,但初始FATT值比常规热处理的锻件高22℃,因此在低温下工作的介临界热处理转子锻件的应力很高,在它的整个使用期间的断裂韧性都可能很低。此外,处于介临界温度的大型锻件之均温过程比常规热处理的同类锻件要困难得多,所用时间也比常规热处理的锻件长得多。
The ASTM Teardown Brittleness Research Group directives have conducted a joint research project with each subsidiary to determine whether the use of intercritical treatment of NiCrMoV steel rotor forgings maintains an excellent balance and improved performance for all of the forgings Its anti-temper brittleness effect. The results show that the above conditions only work well for rotor parts working in the friable range and have no effect on rotor parts working at low temperatures. Forged heat treated forgings have almost no brittleness at 399 ° C but an initial FATT value 22 ° C higher than forge-treated forgings so that the critical heat-treated rotor forgings working at low temperatures have high stresses and fracture throughout their service life Toughness may be low. In addition, the average temperature for large forgings at subcritical temperatures is much more difficult than conventional heat forgings and takes significantly longer than conventional heat-treated forgings.