塑料模具钢4Cr2Mn2Mo厚板的开发

Development of 4Cr2Mn2Mo plastic die steel thick plate

在开发过程中,通过热模拟试验、金相观察确定了塑料模具钢4Cr2Mn2Mo的成分范围和组织构成;通过实验室和大生产试验选取了最佳预硬化工艺制度。研究表明,采用控轧控冷+回火工艺,将终轧温度控制在905℃以上,轧后空冷到300~350℃,缓冷至室温,在560℃下回火的热处理工艺,成功开发出厚度≥150 mm,组织为回火马氏体+贝氏体,硬度均匀且满足钢板预硬态300~350 HBW企业标准要求的模具钢厚板。

Composition ranges and structural constitution of 4Cr2Mn2Mo plastic die steel were determined by thermal modeling test and metallographie observation. A pre hardening process was determined through laboratory test and mass production. The experimental results show that using controlled rolling, cooling and tempering process, die steel plate with thickness above 150 mm is developed successfully by controlling finish rolling temperature above 905 ℃ and air cooling to 300-350 ℃, then cooling to room temperature slowly, finally controlling tempering temperature at 560 ℃. The microstrueture of the steel consists of tempered martensite and bainite, and meet the enterprise standards of uniform hardness between 300 HBW to 350 HBW.