镁对冷作模具钢碳化物及热塑性的影响

冷作模具钢Cr12Mo1V1因C含量和Cr含量高,铸态下在晶界析出大量网状共晶碳化物,锻造后仍会存在大量大块长条状碳化物,且呈带状分布,使钢的热塑性降低,易产生裂纹,限制了其应用.本文研究添加Mg对Cr12Mo1V1钢碳化物及热塑性的影响.随着钢中Mg含量增加,铸态下网状共晶碳化物被打断且被细化,使其在后期的锻造中更容易被打散.同时,锻态下碳化物的平均尺寸随着Mg含量增加而减小,呈均匀弥散分布.碳化物尺寸和分布状态的改善提高了钢的热塑性. 

Effect of magnesium on the carbide and thermoplasticity of cold working die steel

Due to high Cr and C contents,there are a mass of network eutectic carbides precipitating at grain boundaries in the as-cast Cr12Mo1V1 cold working die steel. After forging,most of them are long strip-shaped and have a zonal distribution,leading to a decrease in thermoplasticity,easy formation of cracks,and thus the limit of application. The effects of Mg addition on the carbides and thermoplasticity of the Cr12Mo1V1 steel were investigated in the present study. It is found that with increasing Mg content in the steel,network eutectic carbides in the as-cast steel are interrupted and refined,and can be shattered more easily during the later forging procedure. Meanwhile,the average size of carbides in the forged steel decreases with increasing Mg content,and these carbides present a uniform diffuse distribution. The improvement in size and distribution of carbides enhances the thermoplasticity of the steel.