低碳Mn-Mo-Nb-B钢奥氏体晶粒长大倾向性试验研究

研究了低碳Mn-Mo-Nb-B系钢的韧化方向和韧性控制因素中所涉及的主要问题——原始晶粒控制。研究表明:在1250℃左右的加热温度,5min/mm的保温时间内,钢的奥氏体晶粒仍然保持在50μm左右,为奥氏体的再结晶轧制提供了良好的奥氏体晶粒度,但当加热温度高于1250℃后,出现晶粒急骤长大现象。本试验为该类钢制定更合理的加热制度提供了参考。

Experimental Research on Enlargement Tendency of Austenite Gain in Low-carbon Mn-Mo-Nb-B Series Steels

Studied is the major element among those concerning control of the toughening orientation and toughness of the low-carbon Mn-Mo-Nb-B series steels,i.e.,the control of the primitive gains.The result shows that with heating temperature of about 1 250 ℃ and holding time of 5 min/mm,the austenite grain size still remains as about 50 μm,a very appropriate grain size for austenitic recrystallisation-rolling,and that nevertheless,in case of temperature above 1 250 ℃,the grain size shall become bigger rapidly.This conclusion can be used as refer-ence basis for establishing more logic heating schedule for steels of the above mentioned category.