Uniaxile tensile tests of BH220 bake hardening steel sheet used for the automobile parel were carried out at different temperatures (room temperature-180 ℃). The effect of deformation temperature on tensile properties of the BH220 steel was studied. The results show that the tensile properties of BH220 steel had obviously temperature sensitivity. With the increase of temperature, the yield strength, tensile strength and yield ratio decreased first and then increased, and the critical temperature was about 120 ℃. The strength coefficient K decreased with the increase of temperature, the hardening exponent n decreased first, then increased and decreased again at last. The strain rate sensitivity exponent increased first and then decreased with increasing the temperature,and the critical temperature was about 60 ℃.%对汽车外覆盖件用BH220烘烤硬化钢进行了不同温度(室温～180℃)的单向拉伸试验,主要研究了变形温度对BH220钢拉伸性能的影响.结果表明:BH220钢拉伸性能具有明显的温度敏感性;随着温度的升高,屈服强度、抗拉强度和屈强比呈先降低又升高的规律,其临界温度为120℃左右;强度系数K随温度升高呈下降趋势,硬化指数n呈先降低、后升高和再降低的复杂趋势;应变速率敏感指数随温度的升高先升高后降低,临界温度为60℃左右.
展开▼
