【摘要】 本文研究了６０８钢第二类回火脆性问题。通过实验测得该钢此类脆性的温度区段 约４５０—７００℃．初步探索了通过显微组织鉴别回火脆性的可能性。应用俄歇电子能 谱分析初步确认：回火后缓慢冷却过程中，磷、硼等杂质元素在原奥氏体晶界层的偏 聚，是使该钢产生回火脆性的主要原因；而铬、锰、镍等合金元素的存在及于近晶界 区的偏析，也是促进回火脆化的重要因素。指出了消除该钢回火脆性的途径：当在脆 化温区回火后可施以快速水冷；可在该钢原定成分的基础上附加适量的合金元素相．更多还原

【Abstract】 The secondary temper embrittlement of 608 low alloy cast steel is inves- tigated in this paper. The experimental results show that the temperature of the secondary temper embrittlement range of 608 steel is about from 450°to 700℃.The relation curve between the tempering temperature and the impact va lue is obtained. A method to evaluate the secondary temper embrittlement of 608 steel by microstractural observation is established. Auger electron spectroscopy (AES) analysis shows that the secondary temper embrittlement is caused mainly by the segregation of phosphorous, boron , etc.o at austenitic grain boundary. The existence and segregation of chromium , manganese, nickel, etc. at the austenitic grain boundary are also to increase the brittle tendency of 608 steel. Therefore, it is suggested that quenching through the brittle temperature range or adding enough molybdenum can avoid the secondary temper embrittlement of 608 cast steel.更多还原