Ductile fracture, such as micro-cavities and micro-voids, inevitably exist and evolve under tensile stress state in metal forming. Ductile fracture sways the mechanical performance of 52100 bearing steel. It is necessary to investigate the influences of strain rate and deformation temperature on both ductile fracture and microstructure evolution. Uniaxial hot tension tests were performed, in which specimens were stretched to failure in the temperatures range from 950 °C to 1160 °C and in the strain rates range from 0.01 /s to 1.0 /s. Specimens metallographies have been explored after hot tension. Experimental results show that the peak stress decreases when deformation temperature increases and strain rate decreases. The critical strain of stress–strain relationships increases when strain rate increases. Fracture morphology is severe at higher deformation temperatures and lower strain rates. Hot tension deformation capacity is worst at 1160 °C and a strain rate of 0.01 /s, has been caused by a larger and coarser grain structure.

中文翻译：

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热拉伸下轴承钢的延性断裂和组织

在金属成形过程中，诸如微腔和微孔之类的延性断裂不可避免地存在并在拉伸应力状态下发展。韧性断裂影响52100轴承钢的机械性能。有必要研究应变率和变形温度对延性断裂和组织演变的影响。进行了单轴热拉伸试验，其中将试样在950°C至1160°C的温度范围内以及在0.01 / s至1.0 / s的应变速率下拉伸至破坏。在热张力之后已经探索了标本金相。实验结果表明，当变形温度升高而应变速率降低时，峰值应力减小。应力-应变关系的临界应变随着应变率的增加而增加。在较高的变形温度和较低的应变速率下，断裂形态很严重。热拉伸变形能力在1160°C时最差，应变速率为0.01 / s，这是由较大和较粗的晶粒结构引起的。