Abstract: The effect of C and V content on hardness of non-quenched-tempered pre-hardening plastic die steel (/% : 0.36-0.45C, 0.42-0.46Si, 1.41-1.49Mn, 0.11-0.15 V) has been tested and researched by a 50 kg medium frequency induction furnace in laboratory, and according to regression analysis the vanadium non-quenched-tempered prehardening plastic die steel 48MnV (/% : 0.45-0.50C, 0.30-0.60Si, 1.20-1.40Mn, ≤0.020P, ≤0.020S, 0.15-0.20V) is developed to replace the quenched-tempered plastic die steel P20 (/% : 0.35-0.40C, 0.40-0.60Si, 0.80 -1.00Mn, ≤0.015P, ≤0.015S, 1.50-1.80Cr, 0.30-0.50Mo ). The production results of 110 heats commercial production by 120t BOF-360 mm x 450 mm casting-≤85 mm flat rolling-inline pre-hardening treated with controled cooling rate 0.6-1.0 °C/s flowsheet show that the HRC hardness value of non-quenched-tempered flat of steel 48MnV is 29.5-33.5 to meet the requirement of relative specificalion.

Key words: Non-Quenched-Tempered Steel 48MnV for Pre-Hardening Plastic Die, Vanadium, Development

摘要： 通过实验室50 kg中频感应炉冶炼试验研究了（/%）:0.36~0.45C，0.42~0.46Si，1.41~1.49Mn，0.11~0.15V非调质预硬型塑料模具钢C、V含量对该钢硬度的影响。并根据回归分析开发含钒非调质预硬型模具钢48MnV（/%:0.45~0.50C，0.30~0.60Si，1.20~1.40Mn，≤0.020P，≤0.020S，0.15~0.20V）以取代调质P20塑料模具钢（/%:0.35~0.40C，0.40~0.60Si，0.80~1.00Mn，≤0.015P，≤0.015S，1.50~1.80Cr，0.30~0.50Mo）。经110炉120t转炉-360 mm×450 mm连铸坯-≤85 mm扁钢轧制-控制冷却速度0.6~1.0℃/s的在线预硬化处理的生产结果表明，非调质48MnV扁钢HRC硬度值为29.5~33.5，满足相关技术条件要求。

关键词: 非调质预硬型塑料模具钢48MnV, 钒, 开发