Effect Of EAF-ESR Metallurgy Process On The Purity And Performance Of 35CrMo Steel

35CrMo steel has an extremely important position in the machinery manufacturing industry and is a steel with very promising prospects.In order to improve the metallurgical quality of 35CrMo steel and meet the requirements of higher strength,it is necessary to obtain the purity of steel,that is,the content of inclusions in steel,the composition and distribution of inclusions,and the control of C,N,O,S,H are focused on.This topic explores the inclusions and performance comparison of electric furnace steel and electroslag steel in 35CrMo steel EAF-ESR metallurgical process,and the chemical composition of 35CrMo steel by ingot-type protective atmosphere electroslag furnace and conventional electroslag furnace remelting.A comparative study of mechanical properties reveals a superior smelting process for 35CrMo steel.Through the experimental analysis,the following conclusions are drawn(1)From the metallographic statistics of inclusions before and after electroslag remelting,the average maximum diameter of inclusions in electroslag steel decreased from 1.52 um to 1.46 ?m,and the number of inclusions per unit area decreased from 679/mm2 to 545/mm2.The area percentage of inclusions decreased from 0.21%to 0.16%,and electroslag remelting can improve the cleanliness of 35CrMo steel.(2)After remelting of " three-seven" slag electro-slag,the inclusions are dominated by Al2O3 and inclusions containing Al2O3,and the content of Al2O3 in composite inclusions is significantly higher than that in the electrode.Under scanning electron microscopy,the inclusions containing S element in the steel after electroslag remelting were reduced,and the larger composite inclusions were also reduced.(3)The impact energy was increased from 96.6J to 122.1J,and the tensile strength was increased from 782.3MPa to 800.1 MPa through electroslag remelting.The improvement of purity after electroslag remelting was the main reason for mechanical property increase.(4)Due to the use of Ar gas to protect electroslag remelting,the H,O and N contents of the 35CrMo steel filling end and the bottom pad end produced by the ingot-type protective atmosphere electroslag furnace are significantly higher than those of the conventional electroslag furnace(non-protective atmosphere).35CrMo steel is low.(5)Due to the use of Ar gas to protect electroslag remelting,the 35CrMo steel produced by the ingot-type protective atmosphere electroslag furnace has less C,Mn and Si burning loss than the 35CrMo steel produced by the conventional electroslag furnace(non-protective atmosphere).The chemical composition is more uniform.(6)The steels manufactured by retractable atmosphere protective ESR furnace have better level of B type inclusion(oxide stringers),D type inclusion(globular oxides),and DS inclusion(large globular oxide)compared to that manufactured by conventional ESR furnace.(7)Due to the influence of electroslag filling ratio and melting rate on the crystallization of electroslag ingot,35CrMo steel produced by ingot-type protective atmosphere electroslag furnace,whether it is room temperature mechanical properties or low temperature impact energy of-20?-120?,It is clearly superior to 35CrMo steel produced by conventional electroslag furnace(non-protective atmosphere).