430、444不锈钢连铸坯的高温力学性能研究

Study on high temperature mechanical properties of 430 and 444 stainless steel continuous casting billets

通过Gleeble-1500D热/力模拟试验机对某钢厂生产的430、444两种不锈钢连铸坯进行高温力学性能测试,分析了其高温强度性能和高温热塑性。结果表明,两种不锈钢连铸坯的抗拉强度和屈服强度均随温度的升高而降低,在1 200°C以后抗拉强度<20 MPa,屈服比高达85%~90%,利用率低;430不锈钢连铸坯的第Ⅰ脆性温度区为T_(m)~1 338℃(为常温常压金属熔点),第Ⅲ脆性温度区为800~900℃,在1 050~1 300℃的断面收缩率>60%,塑性较好;444不锈钢的第Ⅰ脆性温度区为T_(m)~1 327℃,在600~1 050℃断面收缩率,塑性较好;另外分别用不同的应变速率进行拉伸比较实验,得出两不锈钢的强度随应变速率的变化关系。

In the paper,the high temperature mechanical properties of 430 and 444 stainless steel continuous casting billets produced by a certain steel plant were tested using thermal/mechanical simulation testing machine,and their high temperature strength properties and high temperature thermos-plasticity were analyzed.The result shows that the tensile strength and yield strength of two stainless steel billets decrease with increasing temperature,above 1 200 °C,the tensile strength is less than 20 MPa,the yield ratio is up to 85%~90%,and the utilization rate is low;The first brittle temperature zone of 430 billet is T_m~1 338 ℃(T_(m) is metal melting point at normal temperature and pressure),the third brittle temperature zone is 800~900 ℃,the section shrinkage of 1 050~1 300 ℃ is more than 60%,and the plasticity is better.The first brittle temperature zone of 444 billet is T_m~1 327 ℃,and the shrinkage rate is more than 60% at 600~1 050 ℃,and the plasticity is better.In addition,tensile experiments were carried out with different strain rates respectively,the relationship change of the strength of two billets with the strain rate was obtained.