摘要
本文研究了残余奥氏体量及其机械稳定性对60Si2Mn 钢氢致开裂敏感性的影响.采用氢脆应力强度门槛值(K_(th))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_(th)值影响不大。回火和充氢处理使残余奥氏体机械稳定性降低,并对氢脆抗力有很大影响。块状残余奥氏体应力诱发转变成马氏体,氢致开裂并形成孔洞。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为裂纹扩展途径,易于开裂。讨论了 K_(th)和 I_H 的变化。
Effects of volume and mechanical stability of retained austenitein 60Si2Mn steel on the resistance to HIC were investigated.The thresholdstress intensity of HIC K_(th) and rate of hydrogen-induced brittleness I_H wereused to assess susceptibility to HIC.The volume of retained austenite from8.4—17.9% did not effect remarkably K_(th),The mechanical stability of retai-ned austenite,subjected to tempered and charged,decreases and it effectsremarkably the resistance to HIC.The blocky retained austenite was transfor-med martensite by stress-inducing,crack was induced by hydrogen and voidwas formed.The void could decreased stress intensity in crack front andraised the resistance to HIC.On the other hand the void could serve asthe path of crack and make cracking easy.The change of K_(th) and I_H hasbeen discussed.
关键词
残余奥氏体
硅
锰
合金钢
氢脆
relained austenite
hydrogen-induced cracking
stability of retained austenite
void
