Q420qD厚钢板的工艺研制

Development of Technique for Q420q D Thick Steel Plate

利用Q420qD在3800宽厚板轧机上进行厚70mm钢板的TMCP工艺试验。结果表明,采用出炉温度在1050～1150℃,加热时间不超过4h,精轧开轧温度为810～850℃,终轧温度为760～790℃,轧后采用层流冷却,终冷温度为610～630℃,未再结晶区总压下率大于40%的工艺生产Q420qD高强度厚板,其屈服强度达到420MPa以上,伸长率达到20%以上,-20℃冲击功达到100J以上。实现了良好的强度和韧性的结合,工艺上省去了热处理工序,降低了生产成本。

TMCP process test of 70 mm thick steel was carried out by using Q420qD and 3 800 heavy plate mill. The results show that the yield strength, elongation and impact energy at -20℃ of Q420qD high-strength plate can reach to 420 MPa, 20% and 100 J respectively, when the following process conditions are adopted： tapping temperature of 1 050～1 150 ℃, heating time of no more than 4 hours, finishing rolling temperature of 810～850℃, final rolling temperature of 760～790 ℃ , laminar flow cooling after rolling, final cooling temperature of 610～640 ℃ and total reduction rate of unrecrystallized zone of more than 40%. A good combination of strength and toughness is achieved, eliminating the need for heat treatment in the process and reducing the production cost.