Cr在球铁中的作用探讨——Cr在铸态球铁中的应用(2)

Discussion on the Effect of Chromium in Nodular Iron——Application of Cr in As-Cast Nodular Iron(Ⅱ)

分析了Cr形成碳化物的能力和在球铁中的分布情况,认为Cr在渗碳体中的含量最多,铁素体中只有微量甚至没有Cr元素;基于合金渗碳体的晶体结构和性能特点,建议将自由渗碳体、网状渗碳体的体积分数控制在1%以内;总结指出Cr在球铁中所起的作用为:促生珠光体,提高强韧性,细化基体,等。

The carbide-forming ability of Cr and its distribution in nodular iron was analyzed. The result showed that the content of Cr in cementite was most high, its content in ferrite only of trace or no; and even no Cr was found at some grain boundaries. Based on the crystal structure and property of the alloyed cementite, it’s suggested to control volumetric fraction of free cemetite and net-type cemetite below 1%. The effect of Cr in nodular iron was summarized as follows: promoting pearlite formation, increase...