DT14钢高温临界损伤值测定与计算机模拟

Determination of High Temperature Critical Damage Value and Computer Simulation of DT14 Steel

采用Gleeble Fracture Limit方法对DT14半钢材料的高温临界损伤值进行了测定,基于Normalized Cockcroft&Latham损伤模型,得到了变形温度为750~1200℃、应变速率为0.01 s-1条件下DT14钢的临界损伤值为0.42~0.52。对实际生产的锻造过程进行了计算机模拟研究,模拟结果表明:镦粗时材料的损伤值最大为0.397,材料处于安全范围内;后续拔长及最后出成品时,在坯料圆角处及底部区域、辊颈与辊身的圆角处损伤值超过了材料的临界值,材料开裂的倾向较大。

The high temperature critical damage value of DT 14 steel was determined in this paper in a method of Gleeble Fracture Limit. On a basis of Normalized Cockcroft Latham damage model,the deformation temperature is750 ～ 1200℃,under the condition of strain rate 0. 01 s～（-1）. the critical damage value of DT14 steel is 0. 42 ～ 0. 52.Computer simulation to the forging process of real production has been researched,the simulation result shows that the maximum damage value of material at upsetting is 0. 397,the material stays in a safe range. At the time of stretching and producing the finished product,the damage value at the billet fillet,the bottom area,the roll neck and the fillet of roll exceed the critical value of material,which makes the trend of crack of material more.