高Cr铸铁大平板亚临界热处理工艺的探讨

介绍了高Cr铸铁的亚临界处理方法,并以w(Cr)17%的高Cr铸铁大平面端衬板为对象,探讨了亚临界处理获得所需硬度的可能,以及亚临界处理对铸态组织要求和热处理工艺参数的作用规律。结果表明,在铸态基体组织主要为珠光体条件下,调整亚临界处理的温度和时间并不能有效提高铸件的硬度;最后通过将w(Mn)量提高到1.5%~1.8%,w(Si)量降低至0.4%~0.8%,使铸态基体以奥氏体为主,在550℃下保温6 h的亚临界处理工艺下,使43~47 HRC的铸态硬度提高到52~54HRC,改善了产品的抗磨性能,且相对于淬火处理减少了能源消耗,也避免高温处理易引起变形的缺点。

Discussion on Subcritical Heat Treatment Process of A Hi-Cr Cast Iron Large Plate

The heat treatment process used for high Cr cast iron was introduced and,by taking an 17% Cr-containing high Cr cast iron large plate as example,the possibility to reach required hardness through sub-critical treatment as well as the effect rule of heat treatment process parameters was discussed. The results showed that,under the condition of as-cast matrix structure consisted mainly of pearlite,it＇s impossible to effectively increase hardness of the casting by adjusting the temperature and duration. Finally by increasing Mn content to 1.5%-1.8% and reducing Si content to 0.4%-0.8% to change the as-cast matrix structm＇e to be consisted mainly of austenite,thus under the sub-critical treatment condition of holding at 550 ℃ for 6 h,it was reached that the as-cast hardness of 43--47 HRC was increased to 52-54 HRC,the anti-abrading property was improved and the energy consumption was reduced compared with quenching treatment, as well as, the disadvantage that high temperature treating was easy to cause deformation was been also avoided.