不同壁厚筒体锻件平均冷却速率研究

Study on Average Cooling Rate of Cylinder Forging of Different Wall Thicknesses

大锻件热处理的特点是成本高、周期长,通常采用与锻件同材料的小试样进行模拟以确定其热处理工艺参数,但模拟的准确度受淬火冷却速度的影响。为此,采用计算机模拟技术研究了不同壁厚大型核电筒体锻件表面以下1/4和1/2壁度处的温度随冷却时间的变化,绘制了锻件壁厚与平均冷却速度之间的关系曲线,并用产品锻件进行了验证。结果表明,小试样试验获得的性能与要求的大锻件性能比较吻合。

Heat treatment of heavy forgings are characterized by high cost and long cycle,as a rule,their heat treating process parameters are determined by simulation with a small sample made of the same material as the forgings,however,the accuracy of the simulation is afected by the quenching rate.For this reason,variation of temperature at 1/4 and 1/2 wall thickness below surface of a heavy nuclear power cylinder forging of different wall thickness with cooling time was investigated by a computer simulation technology.The relationship between wall thickness and average cooling rate of the forging was drawn into curves,and was verfied by the product forgings.The results demonstrated that performances obtained from the small sample were more consistent with those required for the heavy forgings.