钢包材料SM490B钢断裂及中温低周疲劳性能研究

Study on fracture and intermediate temperature low cycle fatigue property of ladle shell material SM490B

针对新型钢包包壳材料SM490B钢,进行了室温断裂韧度、疲劳裂纹扩展速率及350℃(工作状态下,钢包包壳表面的最高温度)下的低周疲劳试验研究。结果表明,SM490B钢的强度和断裂韧度明显高于包壳曾用材料SM41A(Q235)、20g。在试验所取的应力强度因子幅值范围内,与Q235A钢和20g钢相比,SM490B钢的疲劳裂纹扩展速率较快。350℃下的低周疲劳寿命高于压力容器常用钢材16MnR钢300℃下的疲劳寿命。新型钢包包壳材料采用SM490B钢,可大大减少包壳开裂的可能性,提高钢包的承载能力和使用安全性,延长钢包的使用寿命。

Tests on fracture toughness and fatigue crack growth rate at room temperature and low-cycle fatigue at 350 ℃ （maximum service temperature of ladle shell） were carried out for new-type ladle shell material SM490B The results show that the strength and fracture toughness of SM490B steel are much higher than that of SM41A and 20g steel used before. Compared with above-mentioned two materials, fatigue crack growth rate of SM490B steel is relatively higher at the stress intensity factor range in the test. The low cycle fatigue life of SM490B steel at 350 ℃ is longer than that of 16MnR steel at 300℃. Using SM490B steel as ladle material will reduce the possibility of cracking of ladle shell, prolong lifetime and enhance application safety of new-type ladle.