锰对铸铁组织和性能的影响

Effect of Manganese on Microstructure and Properties of Cast Iron

简单阐述了Fe-Mn相图和铸铁中锰的去硫作用及原理;详细介绍了灰铸铁、低锰球墨铸铁中锰对基体组织和力学性能的影响。铸铁中的锰,具有增加白口倾向、减少共晶团数、稳定碳化物和奥氏体等作用,对灰铸铁而言,能提高抗拉强度和硬度、改善淬透性;对球墨铸铁而言,提高抗拉强度和屈服极限的同时降低伸长率,对冲击韧性和脆性转变温度也有不利的影响。此外,锰能与硫化合生成呈致密多角形的硫化锰存在于最后凝固的晶界,从而改善了铸铁的切削性能。

The phase diagram of Fe-Mn and the desulfide action and principle of manganese in cast iron are briefly described.The effect of manganese in gray cast iron and low manganese nodular cast iron on matrix microstructure and mechanical properties was introduced in detail.Manganese in cast iron has the effect of increasing whiteness tendency,reducing eutectic group number,stabilizing carbides and austenite,etc.For gray cast iron,it can improve tensile strength and hardness,improve hardenability;For ductile iron,increasing tensile strength and yield limit while decreasing elongation also has adverse effects on impact toughness and brittle transition temperature.In addition,manganese can be combined with sulfide to form dense polygonal manganese sulfide which exists at the grain boundary of final solidification,thus improving the cutting performance of cast iron.