论文部分内容阅读
利用扫描电镜、透射电镜、X射线衍射和电子探针等研究了0.2C--1.51Si--1.84Mn钢在配分阶段组织的演变情况.配分温度为400℃时,碳在10 s时就可以完成配分,得到残余奥氏体最大体积分数为13.4%.随着配分时间的增长,钢中马氏体发生回火现象,奥氏体发生分解,强度、延伸率降低.当配分时间达到1000 s时,屈服强度、延伸率突然升高.分析认为马氏体回火带来的塑性提高抵消了残余奥氏体量减少引起的塑性降低,并且由于渗碳体和碳化物的析出,变形时阻碍位错的运动,从而提高了屈服强度.通过电子探针分析说明配分阶段发生了碳的扩散,随着配分时间的增长,发生了渗碳体和碳化物的析出,降低了残余奥氏体中碳的含量.
The microstructure evolution of 0.2C - 1.51Si - 1.84Mn steel during the compounding stage was studied by scanning electron microscopy, transmission electron microscopy, X - ray diffraction and electron probe. When the temperature was 400 ℃, carbon could be formed at 10 s After completion of the distribution, the maximum retained austenite volume fraction was 13.4% .With the increase of the partitioning time, the martensite in the steel tempering phenomenon, austenite decomposition, strength, elongation decreased.When the dosing time reaches 1000 s , The yield strength and elongation suddenly increased.The plasticity increase due to the martensite tempering was considered to be offset by the decrease in ductility due to the reduction of the retained austenite amount and hindered by deformation due to the precipitation of cementite and carbide Dislocation movement, thereby increasing the yield strength.Analysis by electron probe shows that the distribution of carbon diffusion stage occurred, with the growing time, the occurrence of cementite and carbide precipitation, reducing the residual austenite Carbon content.