冷却工艺对Si-Mn系热轧双相钢组织和性能的影响

Effect of Cooling Process on Microstructure and Mechanical Properties of Si-Mn Hot-Rolled Dual-Phase Steel

通过热轧试验研究了3种冷却工艺对传统成分Si-Mn系热轧双相钢组织及性能的影响。试验结果表明:在3种冷却工艺条件下,试验钢的最终组织为铁素体和马氏体双相组织。当终轧后采用空冷+超快冷的冷却工艺时,钢板的屈强比最低,伸长率和n值最大,晶粒尺寸较大,但强度相对最小;当终轧后采用层流冷却+空冷+超快冷的冷却工艺时,钢板的晶粒尺寸最小,强度最大;而终轧后直接采用连续的层流冷却工艺时,得到的钢板性能介于两者之间,但冷却工艺相对简单。

The effect of cooling process on microstructure and mechanical properties of Si-Mn hot-rolled dual-phase steel was investigated hy hot-rolled test. The results show that： under the condition of the three tested processes, the final microstructure of the tested steel is composed with ferrite and martensite. When using air cooling plus ul trafast cooling after finishing rolling, the yield ratio of the tested steel is minimum, and the n-value and elongation are maximum, but the grain size of ferrite is larger, and the strengthen is relative minimum; when using laminar cooling plus air cooling and ultrafast cooling after finishing roiling, the grain size of the steel is minimum, and the strengthen is maximum; when using continuous laminar cooling after finishing rolling, the property of the steel is between other two processes, but the cooling process is relative simple.