Study on liquid-liquid bimetal composite casting hammers  

作　　者：Rong Shoufan Zhou Haitao ZhuYongchang Wang Junfa Yao Jia Li Chunhong 

机构地区：[1]Jiamusi University [2]Harbin Institute of Technology

出　　处：《China Foundry》2014年第5期412-417,共6页中国铸造（英文版）

基　　金：financially supported by the National Foundation (grant No:51371090);the Science and Technology Support Program of the 12th Five-year Plan (grant No:2011BAD20B03010401);the National Natural Science Foundation of China (grant No:51203061);the College Student Science and Technology Innovation of Hei Longjiang Province (grant No:2012sj001)

摘　　要：Crusher hammers for the mineral processing industry must meet the demands of both high wear resistance at the hammer head and high impact toughness at the hammer handle. The crusher hammers made of Hadfield steel have typical y low service life of less than 40 hours. To solve the problem, a kind of bimetal crusher hammers made of high chromium cast iron （HCCI） and low al oy steel （LAS） has been successful y developed by using liquid-liquid composite casting. The microstructure and composite interface bonding was analyzed using optical microscope, SEM, EDX and XRD. Micrographs indicate that the composite interface is metal urgical y bonded with a zigzag shape across the boundary and without unbound region or void. After heat treatment, the composite hammers have shown excellent properties. The hardness of HCCI is at least 63 HRC and its αk is greater than 3.5 J？cm-2; the hardness of LAS is greater than 35 HRC and its αk is no less than 80 J？cm-2. Diffusion of elements takes place at the interface and forms a transition region. The micro hardness increases from LAS to the interface and then to HCCI. Wear comparison was made separately between the bimetal composite hammer and a Hadfield steel hammer in two quarries of Jilin province and Liaoning province. The results showed that the liquid-liquid bimetal composite hammers did not have the fal ing off of hammer head or impact fracture phenomenon, and their service life was 3.75 times as long as that of the Hadfield steel hammers.Crusher hammers for the mineral processing industry must meet the demands of both high wear resistance at the hammer head and high impact toughness at the hammer handle. The crusher hammers made of Hadfield steel have typically low service life of less than 40 hours. To solve the problem, a kind of bimetal crusher hammers made of high chromium cast iron(HCCI) and low alloy steel(LAS) has been successfully developed by using liquid-liquid composite casting. The microstructure and composite interface bonding was analyzed using optical microscope, SEM, EDX and XRD. Micrographs indicate that the composite interface is metallurgically bonded with a zigzag shape across the boundary and without unbound region or void. After heat treatment, the composite hammers have shown excellent properties. The hardness of HCCI is at least 63 HRC and its αk is greater than 3.5 J·cm-2; the hardness of LAS is greater than 35 HRC and its αk is no less than 80 J·cm-2. Diffusion of elements takes place at the interface and forms a transition region. The micro hardness increases from LAS to the interface and then to HCCI. Wear comparison was made separately between the bimetal composite hammer and a Hadfield steel hammer in two quarries of Jilin province and Liaoning province. The results showed that the liquid-liquid bimetal composite hammers did not have the falling off of hammer head or impact fracture phenomenon, and their service life was 3.75 times as long as that of the Hadfield steel hammers.

关 键 词：HAMMER liquid-liquid composite casting BIMETAL interfacial microstructure 

分 类 号：TF244[冶金工程]