| Nowadays,low-alloy wear-resistant cast steel,has so low alloy composition,comprehensive mechanical properties,flexible production methods that it is widely applied in sectors such as mining machine,steel,metallurgical and other industries.Which plays a significant role in the domestic metal wear-resistant materials industry.Silicon manganese steel as a low alloy wear-resistant steel,takes place of high manganese steel,used as the materials of a tractor track plate,excavator bucket teeth and other equipment materials.With the continuous development of industrialization,and continuous improvement of equipment requirements,the traditional Si-Mn steel gradually cannot meet the demand for the use of equipment spare parts.In order to better take its cost-effective advantages,this subject is based on silicon-manganese steel,through the optimization of components,process improvement,and the development of new Si-Mn low alloy cast steel,which is meaningful for product upgrading of enterprises lining,bucket teeth and other wear-resistant materials,to provide certain reliable technical support.In this paper,the melting of high purity alloy raw material with industrial pure iron or Q235 steel was used to research the effect of the content of Si and P on the microstructure and mechanical properties of Si-Mn low alloy cast steel.On the basis above,by improving of bottom blowing argon for medium frequency induction furnace,the effect of argon blowing treatment on the microstructure and mechanical properties of Si-Mn low alloy steel was studied in the late stage of melting.What's more,the microstructure and mechanical properties of Si-Mn low alloy steel at different carbon contents were evaluated,and the optimum composition was determined.The effects of quenching temperature and tempering temperature on the microstructure and mechanical properties of Si-Mn low alloy steels were studied after the composition and smelting process.Finally,the optimum performance of Si-Mn low alloy steel was studied by impact abrasion and abrasive wear test,compared with high manganese steel and high chromium cast iron.Research showed that with the increase of S and P content,the hardness of low alloy steel is not changed greatly,and the impact toughness decreased significantly;the later stage of the smelting process of molten steel bottom blowing argon,the hardness of low alloy steel increased lower and the impact toughness increaseed greatly.With the increase of carbon content,the hardness of Si-Mn low alloy steel continued to increase,and increased slowly after 0.4%C.The impact toughness reached the optimum at 0.33%C content,and then decreased with the increase of C content.microstructure was mainly composed of lath martensite,and some residual austenite and lower bainite distribution,the best comprehensive mechanical properties,that is,hardness was HRc 48 and the impact value was Akv42J/cm2.With the increase of quenching temperature,the hardness of the specimen increases and the impact toughness decreases.At 890 ? quenching,the comprehensive mechanical properties of the samples were the best.With the increase of tempering temperature,the hardness was decreased obviously and the impact value was increased slightly,what's more,the mechanical properties of the samples were optimized at the temperature of 220 ?.The best heat treatment process of Si-Mn low alloy cast steel is 880 ? normalizing + 890 ? quenching + 220 ? tempering.The impact wear and abrasive wear tests showed that the hardness of Si-Mn alloy low alloy cast steel was better than that of high manganese steel,and the toughness better than that of high chromium cast iron,which was dense,with better wear resistance in the impact of the environment or abrasive wear environment.The Si-Mn low alloy cast steel has the advantages of lower cost,simple heat treatment process and better comprehensive mechanical property,and can be used for replacing traditional materials such as abrasion resistant lining plate,bucket teeth,etc.and achieved good economic benefits. |
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