热处理工艺对预硬型塑料模具钢组织与性能的影响

Effects of heat treatment on microstructure and mechanical properties of prehardened plastic mould steel

通过研究预硬型塑料模具钢锻后砂冷、350℃回火、500℃回火、退火及退火后500℃回火等不同状态下组织及力学性能并进行分析。试验结果表明,锻后砂冷工艺与其它工艺相比,综合性能良好,锻后砂冷可取代回火处理工艺。试验用塑料模具钢残留奥氏体较少,残留奥氏体对材料力学性能的改善将有限,回火后力学性能变化的主要原因是渗碳体的析出。

Microstructure and mechanical properties of prehardened plastic mould steel forged and heat treated were investigated.The results show that the mechanical properties of forged and sand cooled steel are more preferable than that of the tempered or annealed steel,the forged and sand cooled mould steel can be instead of the tempered mould steel.The residual austenite in the steel is too less to improve the mechanical properties obviously and the precipitation of carbides is the main cause for mechanical property improvement after tempering.