Study On The Process And Optimal Conditions Of Smelting High-quality H13 Steel From High-alloy Scrap Steel

As a high-value recyclable resource,high-alloy steel scrap mainly contains more metals such as Cr,Mo,V,W,Ni,etc.,so it is a high-value recyclable resource.However,the current research level of comprehensive utilization of this kind of resources in our country is still at the preliminary level.It is mixed with ordinary scrap steel and is smelted through ordinary smelting equipment LD converter and EAF electric arc furnace.The existing steelmaking processes are all oxidizing atmospheres.A large amount of high value-added alloy elements are burnt out,and high value-added utilization is not realized.Therefore,it is particularly important to explore a high alloy steel smelting process with high alloy recovery rate and low energy consumption.Based on the existing research and preliminary exploration,this paper systematically studies the alloying element burning loss,molten steel purification,steel structure and properties during the production of high-alloy steel by using high-alloy steel scrap as raw material and adopting the " melting furnace +electroslag remelting" smelting process.And other issues.The results of the smelting experiment show that the high-alloy scrap alloys smelted by the melting furnace have lower alloy burning loss,and the optimal yields of W,Cr,Mo,Ni,and V are: 100.00%,96.89%,100.00%,95.98%,88.73%,respectively.After the molten steel is treated with calcium,the inclusion properties are improved: the maximum length is reduced from 18.54μm to 10.96μm,the average length is reduced from 3.41μm to 2.8μm,and the circularity is increased from 0.2-0.4to 0.8-1.The molten steel ingot is processed by the subsequent electroslag remelting process,and the content of harmful elements H,N,O,P,S in the steel meets the requirements of the national standard.After the smelted H13 alloy steel is processed at different quenching and tempering temperatures,the changes in its structure and properties are analyzed and tested.The experimental results show that the microstructures of quenched at different temperatures are both martensite and ferrite;tempered at 520℃,the crystalline structure is both martensite and ferrite.After the second tempering,the structure is all tempered martensite.That is,after two tempering,ferrite is completely transformed into martensite,and carbides are completely precipitated.This paper uses high-alloy scrap steel as raw material,melting furnace +electroslag remelting short process to smelt H13 alloy steel,and discusses the smelting and heat treatment conditions for obtaining high alloy yield,low harmful element content,and excellent steel texture.The direct smelting of high-quality alloy steel with high-alloy steel scrap provides a process route and a direction for the efficient utilization of high-alloy steel scrap.