大型锻件内部脆性夹杂物边界裂纹是影响其疲劳寿命与冲击性能的主要缺陷,热锻变形下应变速率与应力状态是影响大型锻件内部脆性夹杂物边界裂纹形成的两个主要因素。在Gleeble-3180热模拟试验机上,对试件进行了不同应变速率的热镦粗变形,在扫描电镜上观察了试件内部脆性夹杂物边界裂纹的形成规律。试验表明,在1220℃镦粗变形条件下,当应变速率小于1×10-5s-1时,脆性夹杂物边界没有裂纹形成;当应变速率大于1×10-5s-1时,脆性夹杂物边界易破裂。 The main defects of brittle inclusions in large forgings are the main defects that affect their fatigue life and impact properties. The strain rate and stress state under hot forging are the two main factors that affect the formation of boundary cracks in brittle inclusions in large forgings. On the Gleeble-3180 thermal simulator, the specimens were subjected to hot upsetting deformation at different strain rates. The formation of boundary cracks on the brittle inclusions was observed by SEM. The experimental results show that there is no crack at the boundary of brittle inclusions when the strain rate is less than 1 × 10-5s-1 at 1220 ℃ upsetting deformation. When the strain rate is more than 1 × 10-5s-1, the boundary of brittle inclusions Easy to break.