阀片钢3Cr13的热处理工艺研究

Research on Heat Treating Processes for Valve Plate Steel 3Cr13

研究了阀片钢３Ｃｒ１３经两种热处理后组织和性能的变化规律。试验结果表明，要求高硬度（５２ＨＲＣ）的阀片可采用１０５０℃油淬、２５０℃×２ｈ回火，或采用１０００℃加热、于２４０℃等温１５ｍｉｎ、３００℃×２ｈ回火；要求较低硬度（４０ＨＲＣ）的阀片，则可采用１０５０℃油淬、５５０℃×２ｈ回火的调质处理，或１０００℃加热、于２４０℃等温１５ｍｉｎ、５５０℃×２ｈ回火。弯曲疲劳模拟试验表明，高硬度的等温处理具有最长疲劳裂纹萌生期Ｎｏ和最高的疲劳强度，较低硬度的调质工艺也同样获得很高的Ｎｏ和良好的疲劳性能。

The relationship between microstructures and properties of the valve plate steel 3Cr13 after undergoing two heattreating processes has been studied in this paper According to experimental results,the available heat treating processes have been chosed as follows:heating to 1050℃,quenching in oil and tempering at 250℃×2h or heating to 1000℃,isothermally cooling in 240℃ bath within 15min,and tempering at 300℃×2h for the valve plate required the higher hardness(52HRC).Otherwise,for the valve plate required the lower hardness(40HRC),the similar quenching processes and tempering at 550℃×2h respectively may be used The analogoue bending fatigue experiments show that the longest period of the fatigue crack initiation( N o)may be obtained by the higher hardness valve plate using the isothermal heat treating process The high N o and good fatigue strength of the lower hardness valve plate using quench hardening and tempering are also obtained