Cr12冷作模具钢下贝氏体/马氏体复相热处理工艺的研究

Study on Heat Treating of Bainite/Martensite Dual Phase of Cr12 Cold Work Die Steel

研究了下贝氏体／马氏体复相热处理工艺对Cr12钢显微组织与性能的影响。Cr12钢于1030℃加热奥氏体化，在280℃等温1～4h，获得不同百分比的下贝氏体／马氏体组织，测定相应的耐磨性及冲击韧性，并与常规热处理的Cr12钢进行了比较。结果表明，7％～10％贝氏体／马氏体复相显微组织能赋予Cr12钢以良好的韧性与耐磨性配合。本文对这种复相组织进行了分析及讨论。自行车把节头的凸袋模系Cr12钢制的冷镦模，采用贝氏体／马氏体复相热处理工艺代替常规的分级淬火，其使用寿命可提高3～4倍，现已应用于生产。

In this paper the influence of the heat treating of low Bainite/Martensite dual phase on microstructures and properties of Cr12 steel has been studied. After austenitizing at 1030℃,different per cent of low Bainite/Martensitic structure of Cr12 steel can be obtained with 1~4h isothermal cooling at 280℃,then corresponding property of wear resistance and impact toughness compared with normal heat treating of Cr12 steel has been tested. The result showed that the microstructure of 7%~ 10% Bainite/Martensite dual phase has optimal matching of toughness and wear resistance on Cr12 steel. Instead of normal martempering the heat treating of Bainite/Martensite dual phase can increase the punch die life of bicycle,s handle node made of Cr12 steel by more than 3 ~ 4 times.