稀土硼对30CrMn2Si铸钢组织转变的影响

The Effect of RE-B on Structures Transformation of 30CrMn2Si Cast Steel

本文通过光镜、透射电镜、扫描电镜研究了稀土硼对30CrMn2si铸钢组织转变的影响。研究结果表明:稀土硼减缓了奥氏体的分解,使钢的淬透性和临界淬透直径增加,Ms点升高。稀土硼还能使铸态组织细化,铁素体数量增多,并能抑制孪晶马氏体形成,增加位错马氏体比例,改善回火碳化物形状、数量及分布。增加淬火组织中残余奥氏体数量。从而使钢的性能得以改善。

In this paper, effect of RE—B on structure transformation of 30CrMn2Si cast steel has been studied by means of metalloscope, TEM and SEM. The results show that RE—B slow down the rate of austenite transformation. Therefore the hardenability and critical hardening diameter of the steel are increased and Ms temperature is enhanced. RE—B can increase amount of ferrite, refine as cast structures, decrease amount of twined martensite, increase the proportion of dislocated martensite. It improves the shape、amount and distribution of temper carbide as well as the amount of remained austenite in quenched structure. That results are in improving of the properties of steels.