本文選題：車輪鋼　切入點(diǎn)：逆相變　出處：《鋼鐵》2015年07期

【摘要】：針對碳質(zhì)量分?jǐn)?shù)為0.47%中碳高鐵車輪鋼,研究了鈮微合金化對前驅(qū)體為鐵素體-珠光體的組織發(fā)生奧氏體逆相變的影響。結(jié)果表明,鐵素體-珠光體鋼的逆相變是一個(gè)由碳原子擴(kuò)散控制的過程,奧氏體優(yōu)先在珠光體內(nèi)的鐵素體與滲碳體(α/Fe3C)片層界面處形核,并且沿平行于珠光體片層方向的長大速率比垂直于珠光體片層方向更快。含鈮車輪鋼細(xì)化的珠光體組織可以提高奧氏體的形核率,有利于細(xì)化奧氏體晶粒。隨著再加熱溫度的提高,含鈮車輪鋼的奧氏體混晶溫度(960℃)比不含鈮的鋼高80℃,因此通過鈮微合金化可擴(kuò)大再加熱奧氏體化溫度窗口。結(jié)合Thermal-Calc熱力學(xué)計(jì)算和透射電鏡分析,鈮在中碳鋼中主要以析出物的形式存在,析出釘扎作用是其細(xì)化奧氏體晶粒、推遲混晶現(xiàn)象出現(xiàn)的主要機(jī)制。
[Abstract]:The effect of niobium microalloying on the inverse austenitic transformation of the precursor ferrite pearlite was studied for the medium carbon high iron wheel steel with a carbon content of 0.47%. The inverse transformation of ferrite-pearlite steel is a process controlled by the diffusion of carbon atoms. The austenite nucleates at the interface between ferrite and cementite (偽 / Fe _ 3C) lamellar layer. And the growth rate along the direction parallel to the pearlite lamellar is faster than that perpendicular to the pearlite lamellar. The nucleation rate of austenite can be increased by the refinement of pearlite structure of niobium wheel steel. With the increase of reheating temperature, the austenite mixed crystal temperature of the wheel steel containing niobium is 960 鈩，

本文編號：1687712