摘要
通过在Ｇｌｅｅｂｌｅ—１５００热模拟试验机上进行热拉伸试验，研究了ＳＣＭ４２０齿轮钢在高温下的热塑性及变形断裂的行为与机制。结果表明，ＳＣＭ４２０钢在７５０～９００℃和在１３５０℃以上时出现沿晶脆性断裂，在９５０～１３００℃为穿晶断裂；在沿晶断裂过程中，晶界处的硫化物粒子作为应力集中核心促进了微孔聚合或晶界滑移，恶化了塑性；拉伸变形前的预相变过程促进了固溶温度较高的（ＭｎＦｅ）Ｓ粒子的大量析出，从而严重恶化了ＳＣＭ４２０钢的热塑性，使塑性凹槽向高温区扩展了约１５０℃左右。
The strength and ductility of a kind of low carbon alloy steel under temperature from solidus to 600 were investigated on thermal stress/strain simulator Gleeble1500, and the behavior and mechanism of crack propagation were studied. The results are as follows: In the temperature range of 750900 and above 1 350 , intergranular fracture is observed, and transgranular rupture is observed in range of 950 1 300 . Sulphide particles at grain boundaries can act as nuclei of microvoid formation and impair hot ductility;phase transformation prior to deformation promotes the precipitate more (MnFe)S particles, whose solution temperature is higher than Fe (SO), and seriously deteriorates the hot ductility of SCM420 steel.
出处
《钢铁》
CAS
CSCD
北大核心
1999年第3期47-52,共6页
Iron and Steel
基金
国家"九五"攻关合金钢连铸项目
关键词
汽车
齿轮钢
热塑性
热拉伸试验
钢
hot ductility, grain boundary sliding, grain boundary migrating, intergranular fracture, transgranular fracture
