The Research Of Steel Bond Hard Alloy-Cast Steel By Cast-in Process

Composite material is the new material made by two or the more kinds of materials which physics, chemistry, mechanics property are different by firm metallurgy combine in the interface. Despite the property of each kinds of materials remain intrinsic property, the physics, chemistry, mechanics property of composite material are more excellent. This paper through the manufacture of the steel bond hard alloy-cast steel hammerhead, The Cast-in Process between steel bond hard alloy and cast steel was discussed.First, the steel bond hard alloy-iron bimetal composite material is made by powder metallurgy method. In this process, manufacture technics of the steel bond hard alloy-iron bimetal composite material and influential elements are explored, and the experiment conclusion as follows.(1) In the process of steel bond hard alloy-iron bimetal composite material was manufacture by powder metallurgy method, the shrinkage of two different material were not same when liquid phase sintering and cooled.(2) Steel bond hard alloy-iron bimetal composite material should has certain thickness when composite material was manufacture by powder metallurgy method. The stress of the inner of bimetal composite material was great, so anneal and quencher before use for enhancing the rigidity was necessary.(3) In the steel bond hard alloy-iron bimetal composite material, thepolygonal carbide (WC, Cr_21.34Fe_1.66C₆ )and rounded carbide (Fe₃W₃C, Cr_<sub>21.34Fe_1.66C₆)were existent in the sintering body, the strength of bimetal composite the interface was greater than that of steel bond hard alloy.(4) The hardness in interface and the microstructure varied smoothly, the connection of two materials was good.Later, the manufacture technics, principles, influential elements are researched in this paper in the process of hammerhead was manufactured by Cast-in Process between the steel bond hard alloy-iron bimetal composite material and cast steel. At one time, the heat treatment, abrasion, capability were also studied, and draw a conclusion as follows.(1) During Cast-in Process between the steel bond hard alloy-iron bimetal composite material and cast steel, melting, infiltration occurred in the interface. Junction area is thick and the interface was formed by metallurgy.(2) Pouring temperature, the ratio of the weight between liquid and solid, the position of the steel bond hard alloy, the pre-treatment of steel bond hard alloy, the pre-treatment of cavity and so on manufacture process affected the quality of hammerhead during Cast-in Process.(3) The rigidity of the steel bond hard alloy reduced, compare with the one before Cast-in Process. The reason of this phenomenon was the high temperature anneal of the steel bond hard alloy during the Cast-in Process. The carbide in the steel bond hard alloy is steady when heated, so the rigidity of the carbide was not changed markedly. But the rigidity of the base reduced because of the high temperature anneal.(4) The character of the steel bond hard alloy was a mass of carbide was distributed in the base made of martensite, abstruse, exiguous carbide mainly after quenching then tempering. The intensity and the toughness were high after tempering. The high rigidity of the steel bond hard alloy owe to both the high intensity of the base and the distributing of a mass of carbide.(5) As for the steel base of the steel bond hard alloy-cast steel hammerhead, thestructure of surface was martensite and abstruse and the structure of middle was P+F.(6) The abrasion of the composite hammerhead was fast in the first phases, and the speed of the abrasion reduced then remains stability in the second. In the third phases, the speed of the abrasion quickened, entering another fast abrasion phases.(7) Manufacturing the steel bond hard alloy-cast steel hammerhead by Cast-in Process was doable, the composite hammerhead had excellent property of resisting abrasion and rupture.