破碎机环锤制造工艺及性能研究

Study on Manufacture Process and Mechanical Property of Crusher Ring-hammer

针对环锤在使用过程中易出现裂纹、断裂、耐磨性差及使用寿命短的缺点,通过成分优化、新型铁砂造型—螺旋环冷铁的消失模铸造工艺及沉淀强化热处理工艺设计,成功开发一种以普通高锰钢为基础添加合金元素,经复合变质处理后,初始硬度达210HB,冲击韧度在215J·cm-2以上的高耐磨钢。研究结果表明,该钢经多元微合金化、复合变质处理后,奥氏体基内形成弥散分布的合金碳化物等第二硬质相颗粒,强化了基体,提高了材料的初始硬度。当采用铁砂造型时,铁砂既体现型砂的固有特性又充当金属型的作用,使铸件的晶粒得到细化,组织致密度得到提高。生产实践证明:按此工艺生产的环锤件,经1080℃保温4h水淬+320℃保温3h回火的沉淀强化处理,抗拉强度σb=724MPa,冲击韧度αk=219J·cm-2,断后伸长率δ=37%,布氏硬度210HB,可满足产品使用性能要求,在实际使用中获得良好的耐磨效果,具有明显的市场竞争优势。

In view of the weakness of ring-hammer such as cracks,breakages,poor wear resistance and short service lifet,a high wear-resistant steel with initial hardness up to HB 210 and impact ductility above 215 J·cm^-2 is developed successfully,which is based on the high manganese steel with the addition of alloy agents and composite modification,by designing component,designing processes which include a new lost foam casting process of iron-sand molding spiral-ring chill and a heat treatment for precipitation strengthening.The results show that after multi-element microalloying and composite modification,second hard phase particles such as alloy carbides are formed and dispersively distributed in the austenitic matrix,thereby strengthening the matrix and improving the initial hardness of material.When iron sand is adopted for molding,it not only has the inherent characteristic of molding sand but also plays the function of metal mold,so that the grains of casting are refined,and the microstructure density is improved.The production practice shows that the properties of the ring-hammer produced on the basis of such technique can be obtained as follows：tensile strength σb=724 MPa,impact toughness αk=219 J·cm^-2,percentage elongation δ =37%,Brinell hardness 210 HB respectively after precipitation strengthening treatment by water quenching at 1 080 ℃ for 4 h and tempering at 320 ℃ for 3 h,which can meet the application requirements,the products have good wear-resistant property in practical application and obvious market competitive advantage.