摘要
本文研究了残余奥氏体量及其力学稳定性对60Si2Mn 钢氢致开裂敏感性的影响。采用氢脆应力强度门槛值K_■和氢致脆化率 I_H评定材料氢致开裂敏感性。残余奥氏体量(8.4～17.9%)对 K_■值影响不大。经回火和充氢处理,残余奥氏体力学稳定性降低。残余奥氏体力学稳定性对氢脆抗力有很大影响。由块状残余奥氏体应力诱发转变生成马氏体,并氢致开裂,形成孔洞。一方面孔洞能降低裂纹尖端应力和提高氢脆抗力,另一方面,孔洞也可作勾裂纹扩展途径,易于开裂。还讨论了K_■和I_H的变化和不一致性。
Effects of volume and mechanical stability of retained austenite in 60Si2Mnsteel on the resistance to HIC were investigated.The threshold stress intensityof HIC,K_(th) and rate of hydrogen-induced brittleness,I_H were used to assesssusceptibility to HIC.Volume of retained austenite,form 8.4% to 17.9%,didnot effect remarkably K_(th).The mechanical stability of retained austenite,sub-jected to tempered and hydrogen charged,decreased and effected remarkably theresistance to HIC.Martensite transformed form the blocky retained austen iteby stress-induced cracked by hydrogen and void was formed.The void coulddecrease stress intensity in crack fornt and raised the resistance to HIC,onthe other hand,void could serve as the path of crack and make craking easily.The change of K_(th) and I_H in different extent has heen discussed.
关键词
残余奥氏体
力学稳定性
氢致断裂
retained austenite
mechanical stability
hydrogen-induced brittleness
