Cr和Al加速亚共析钢层状渗碳体球化的机理

Mechanism of accelerated spheroidization of lamellar cementite in hypoeutectoid steel by addition of Cr and Al

根据亚共析精冲钢的实际生产情况并结合Gleeble热模拟试验,研究发现添加Al的质量分数为0.08%或Cr的质量分数为0.25%时均可加速热轧亚共析钢中层状渗碳体的球化速度。利用内耗技术研究了Cr元素、Al元素对渗碳体球化退火影响的机理。研究表明,Cr可降低C原子的扩散激活能,加速C原子扩散速度从而提高球化效率。Al则主要通过钉扎作用细化渗碳体片层间距,实现球状渗碳体尺寸细化的效果。

According to the actual production situation of hypoeutectoid steel,it is found that the addition of 0.08 mass% Al or 0.25 mass% Cr both can accelerate the spheroidization rate of the lamellar cementite in the hot rolled hypoeutectoid steel studied by gleeble thermal simulation.The internal friction technique was used to study the mechanism of the effect of Cr,Al elements on the cementation annealing of cementite.The internal friction studies reveal that Cr can reduce the diffusion activation energy of C atoms,accelerate the diffusion rate of C atoms,thereby improving the spheroidization efficiency.Al is mainly through pinning effect to refine cementite sheet spacing,achieving the effect of spherical cementite size refinement.