The Effect Of Tempering Behavior Of Microstructure Modifications And Properties In 45 Steel By High Current Pulsed

In order to improve wear-resisting performance and corrosion resistance of 45 steel surface,45 steel surface is irradiated by HCPEB,than 45 steel surface is conducted by tempering after HCPEB irradiation.By studying microstructure and mechanical properties of the surface of 45 stee after HCPEB irradiation,to discuss the effect of tempering on microstructure and mechanical properties of the surface of 45 stee after HCPEB irradiation and to clarify the effect of tempering on wear resistant and corrosion resistant performance of 45 steel after HCPEB irradiation.The results show that,remelting layer which is about 4-5 microns is formed on the surface of 45 steel after HCPEB irradiation.With the increase of energy density and irradiation times,the number of melt holes on the surface of 45 steel rises then decreases.With the increase of energy density and irradiation times,the number of residual austenite on the surface of 45 steel increases,the main reason is that martensitic transformation stop by the speed of cooling at the end of irradiation.With the increase of energy density and irradiation times,the wear resistance of the surface of 45 steel decreases then rises.With the increase of energy density and irradiation times,corrosion resistance performance of 45 steel is better,the main reason is that irradiation makes the the carbide of the surface dissolute and reduces the formation of pitting corrosion.With the increase of tempering temperature,the remelting layer on 45 steel surface will disappear and substrate.With the increase of tempering temperature,the surface hardness of 45 steel of 4.9 % retained austenite rises then decreases.In the tempering temperature of 200? the surface hardness is max,the main reason is that all residual austenite on the surface dissolves and it makes surface hardness increases.For 45 steel of 19.9 % retained austenite,the surface hardness is min in the tempering temperature of 200?,the main reason is that temper to reduce the internal stress produced by the irradiation and to eliminate dislocation,at the same time tempered martensite is generated.The surface hardness is max in the tempering temperature of 300 ?,the main reason is that all residual austenite resolves on the surface of the 45 steel.For 45 steel of 4.9 % retained austenite,the surface wear rate in 150? tempering is bigger than the surface wear rate without tempering and the surface wear resistance in 150? tempering is worse than the surface wear resistance without tempering.When the tempering temperature to 200 ?,wear rate decreases and wear resistance increases.The main reason is that all residual austenite resolves on the surface of the 45 steel.Along with the tempering temperature continues to rise,wear rate first increases then decreases.For 45 steel of 19.9 % retained austenite,the surface wear rate in 150? tempering is bigger than the surface wear rate without tempering and the surface wear resistance in 150? tempering is worse than the surface wear resistance without tempering.When the tempering temperature to 300?,wear rate decreases and wear rate is min,at the same time the wear-resisting performance is the best.The main reason is that all residual austenite resolves on the surface of the 45 steel.When the tempering temperature is 400 ?,wear rate increases and wear-resisting performance becomes poor.For 45 steel of 4.9 % retained austenite,the surface corrosion resistance after tempering is worse than the surface corrosion resistance without tempering,this is mainly due to the precipitation of surface carbide after tempering.When the tempering temperature is 200?,the corrosion resistance of 45 steel surface is excellent.For 45 steel of 19.9 % retained austenite,with the increase of tempering temperature,the surface corrosion resistance rises then decreases.When the tempering temperature is 300?,the corrosion resistance of 45 steel surface is excellent.