控轧控冷工艺对冷镦铆螺钢组织和力学性能的影响

试验钢(/%:0.19C,0.17Si,0.44Mn,0.004S,0.007P,0.041Als),由60kg真空感应炉熔炼,锻成120mm×140mm坯,轧成80 mm×80mm坯,再轧成4 mm×100mm成品。试验了950℃、800℃终轧和轧后水冷、空冷对该钢组织和性能的影响。结果表明,实验钢1000℃开轧,经二道次轧制,800℃终轧,以32.33～37.50℃/s的冷却速度水冷,工艺最佳,低碳钢珠光体为89%,铁素体晶粒尺寸38 nm达到了铆螺钢ML45级别。950℃终轧,水冷,力学性能达到了ML40级别。800℃终轧,空冷钢的力学性能也能达到ML30级别。

Effect of Controlled Rolling and Cooling Process on Structure and Mechanical Properties of Mushroom Cold Upsetting Steel

The tested steel (/% : 0. 19C , 0. 17Si, 0. 44Mn, 0. 004S, 0. 007P, 0. 041 Als) is melt by a 60 kg vacuum induction furnace, forged to 120 mm x 140 mm billet, rolled to 80 mm X 80 mm billet and rolled to 4 mm X 100 mm product. The effect of finished rolled at 950 °C and 800 °C water and air cooling process on structure and properties of steel has been tested. Results show that the optimum process is beginning rolling at 1 000 °C , two passes of deformation in hot rolling, finished rolled at 800 °C, water cooling with cooling speed 32. 33 ~37. 50°C /s, best process, the performance of low carbon steel with pearlite 89% and ferrite grain size 38nm is up to rating of mushroom upsetting steel grade ML45, the mechanical properties of steel with finished rolled at 950 °C water cooling is up to steel grade ML40 and the mechanical properties of steel with finished rolled at 800 °C air cooling is up to steel grade ML30.