摘要
500 MPa级高强钢-20℃冲击功均值为18 J,针对冲击功不合格的高强钢,利用金相显微镜检测钢板组织,发现铁素体尺寸大小差异大、表面和芯部组织差异大,且芯部有少量珠光体。分析认为铁素体尺寸不均产生的原因是精轧第三机架轧制后发生了部分再结晶,造成奥氏体尺寸不均,并遗传至铁素体。芯部少量珠光体是由于卷取温度较高、冷速慢造成奥氏体发生了珠光体转变。通过提高精轧速度和降低卷取温度解决了500 MPa级高强钢冲击功不合格的问题。
The average impact energy of 500 MPa grade high-strength steel is 18 J at-20 ℃. For the high-strength steel with unqualified impact energy, the microstructure of the steel plate was inspected by metallographic microscope. It was found that the size of ferrite was nonuniform, the microstructure of surface and core was different. Moreover, there were few pearlites in the core. The analysis showed that the reason to cause nonuniform size of ferrite was the partial recrystallization after the third stand of finish rolling, resulting in the nonuniform size of austenite, which was then inherited to the ferrite. Few pearlites in the core were due to the pearlite transformation from austenite under high coiling temperature and slow cooling speed. By increasing the finishing speed and reducing the coiling temperature, the problem of unqualified impact energy of 500 MPa high-strength steel was solved.
作者
申延军
SHEN Yanjun(China Metallurgical News,Beijing 100029,China)
出处
《物理测试》
CAS
2022年第6期33-35,共3页
Physics Examination and Testing
关键词
高强钢
冲击功
部分再结晶
珠光体
high-strength steel
impact energy
partial recrystallization
pearlite
