磷、碳质量分数对粉末冶金高锰无磁钢组织与性能的影响

Effect of phosphorus and carbon mass fractions on microstructure and properties of PM high manganese non-magnetic steels

在高锰钢合金粉中添加不同质量分数Fe3P粉和石墨粉,采用压制烧结方法制备Fe–Mn–P–C无磁钢平衡块零件,研究了磷、碳含量(质量分数)对高锰无磁钢组织与性能的影响,并比较了Fe–Mn–P–C高锰钢与Fe–Mn–Cu–C高锰钢的性能。结果表明:添加Fe3P粉到高锰钢粉末中可以制备出组织均匀的无磁高锰钢。烧结件的密度和硬度随Fe3P添加量的增加而增大,当添加Fe3P质量分数超过2%之后,烧结件的密度基本保持不变;添加质量分数3%Fe3P的烧结件硬度最大,达到HRB 95左右。添加Fe3P质量分数小于1%的烧结件呈现无磁特性,添加Fe3P质量分数为2%时,烧结件呈现弱磁特性,添加Fe3P质量分数为3%时,烧结件呈现强磁特性。烧结件的密度和硬度随着石墨添加量的增加而增大,添加质量分数0.30%石墨时,烧结件的密度超过7.30 g·cm^(-3);石墨添加量小于0.30%时,烧结件呈现无磁特性;石墨添加量为0.60%时,烧结件呈现弱磁特性;石墨添加量超过0.75%时,烧结件呈现强磁特性。与Fe–Mn–Cu–C高锰钢相比,Fe–Mn–P–C高锰钢的密度相对较低,硬度和磁性与Fe–Mn–Cu–C高锰钢相当,但力学性能均优于Fe–Mn–Cu–C高锰钢。

Fe–Mn–P–C non-magnetic steel balance block parts were prepared by pressing-sintering method by adding Fe_(3)P powders and graphite powders in different mass fraction to the high manganese steel alloy powders.The effects of phosphorus and carbon content on the microstructure and properties of high manganese non-magnetic steels were studied,and the properties of Fe–Mn–P–C high manganese steels and Fe–Mn–Cu–C high manganese steels were compared.The results show that,the non-magnetic high manganese steels with the uniform structure can be prepared by adding Fe_(3)P powders to the high manganese steel powders.The density and hardness of the sintered parts increase with the increase of Fe_(3)P content.When the Fe_(3)P mass fraction exceeds 2%,the density of sintered parts remains basically unchanged.The hardness of sintered parts with 3%Fe_(3)P is the highest,reaching about HRB 95.When the Fe_(3)P mass fraction is less than 1%,the sintered part shows no magnetic characteristics;when the Fe_(3)P mass fraction is 2%,the sintered part shows the weak magnetic characteristics;when the Fe_(3)P mass fraction is 3%,the sintered part shows the strong magnetic characteristics.The density and hardness of sintered parts increase with the increase of graphite content.When 0.30%graphite is added,the density of sintered parts exceeds 7.30 g∙cm^(−3).When the graphite mass fraction is less than 0.30%,the sintered part shows no magnetic characteristics;when the graphite mass fraction is 0.60%,the sintered part shows the weak magnetic characteristics;when the graphite mass fraction is 0.75%,the sintered part shows the strong magnetic characteristics.Compared with the Fe-Mn-Cu-C high manganese steels,the density of Fe-Mn-P-C high manganese steels is relatively low,and the hardness and magnetism are equivalent,but the mechanical properties are better than that of the Fe-Mn-Cu-C high manganese steels.