Study On Hot Rolling Forming And Heat Treatment Of 40Cr/Q345 Bimetal Ring

With the development of industry,the requirements for ring parts increase,the performance of single metal ring parts is often unsatisfactory,and bimetal ring parts are paid more attention.Bimetallic ring is a kind of ring which combines two kinds of metals with different physical and chemical properties by a certain technology,so that the ring has the advantages of both metals.Bimetallic ring can replace precious material and improve performance.In order to solve the problems of complicated production process and poor combination of inner and outer layers,our team put forward a short process.The process has high production efficiency,energy saving and emission reduction,metallurgical bonding layer and high bonding strength.Through theoretical research,the technological parameters of rolling were selected and the hot rolling experiment of bimetal ring was carried out.The ring after rolling was tested by flaw detection,metallographic structure,element diffusion and mechanical properties test.After ring rolling,the ring was quenched at different temperatures(860 ℃,890 ℃,920 ℃,950 ℃)and tempered(520 ℃,550 ℃,580 ℃,610 ℃).The final conclusion is as follows:(1)Bimetallic ring with qualified flaw detection and good bonding was obtained after rolling.The hot rolling process of bimetal ring is feasible.(2)With the increase of rolling ratio,the tensile strength of bimetallic rings increases first and then decreases.With the increase of initial rolling temperature,the tensile strength of 40 Cr decreases,the tensile strength of bond layer and Q345 first increases and then decreases,and the plasticity of 40Cr/Q345 bimetallic ring decreases.(3)With the increase of initial rolling temperature,the diffusion degree of bonding layer elements increased.With the increase of rolling ratio,the diffusion degree of bonding layer increases.(4)890 ℃ is the best quenching temperature.With the increase of tempering temperature,the overall strength of bimetallic ring decreases and the plasticity increases.After tempering at 550 ℃,the strength and ductility of the ring are high,which meet the requirements of use.890 ℃ quenching 550 ℃ tempering is the best heat treatment process parameter for 40Cr/Q345 bimetallic ring,under which the comprehensive performance of40Cr/Q345 bimetallic ring is the best.