微合金钢超细组织的控制轧制

Controlled Rolling of Microalloyed Steels for Ultrafine Ferrite

探讨了采用应变诱导轧制及应变诱导轧制与常规控轧技术相结合获得超细晶铁素体组织的可行性 ,研究了冷却速度对应变诱导铁素体晶粒长大的影响。实验结果表明 ,采用应变诱导轧制可显著细化铁素体组织 ;将应变诱导轧制技术与常规控轧工艺相结合所获得的超细晶组织更为理想。通过实验室模拟轧制 ,已获得体积分数为 97%、晶粒尺寸达 0 .92 μm的超细铁素体组织。TEM分析发现 ,超细晶铁素体内位错密度较低并有少量小角度晶界存在。

The possibilities that ultrafine ferrite is transformed by strain inducing controlled rolling and strain inducing controlled rolling combined with conventional controlled rolling have been researched. The effect of cooling rate on ferrite grain size has been researched too. The results showed that the ferrite grain can be refined by strain induced transformation. The microstructure of the steel processed by strain inducing controlled rolling combined with conventional controlled rolling is more desirable. Ultrafine ferrite with volume fraction of 97 % and 0.92 μm in grain size has been obtained in laboratory. The TEM analysis showed that there are low dislocation density and some low angle boundaries in ultrafine ferrite.