15-5 Ph Martensitic Precipitation Hardening Stainless Steel Friction And Wear Properties Of The Research

15-5PH (OCr15Ni5Cu3Nb) is a kind of martensite precipitation hardening stainless steel, after solution, it forms the martensite with low carbon, during ageing treatment, the carbide and rich of ε-Cu compounds precipitate as lattice hardening phase, thus the matrix is strengthened. Because of the excellent comprehensive mechanical properties,15-5PH steel is particularly suitable for the manufacture of high strength corrosion resistance of precise components, it is also the ideal mold material. But the fly in the ointment is the low hardness after ageing treatment, meanwhile its wear resistance is low, which restricts its use of performance and lifetime. In this paper, through observing the microstructure morphology of15-5PH at different solution and ageing temperature with the help of metallurgical microscope and SEM, then researching the influences of heat treatment on the hardness of15-5PH; Examining the composition of wear surface and wear debris by EDS, in order to study the influence on microstructure and wear resistance of15-5PH after different solution and ageing temperature, and then find the heat treatment when the15-5PH have the best wear resistance; At the same time, researching how the different experimental conditions (such as load, sliding speed, the environment temperature) effect on the friction and wear properties of15-5PH steel, and then the wear mechanism of15-5PH steel was explored on the above basis.The results show that:the hardness of15-5PH rises obviously after ageing compared with the state of solution, in100℃to600℃ageing range, with the increases of ageing temperature, the hardness of the steel increases first and then decreases, in450℃shows a maximum value.Different solution temperature and ageing temperature has a remarkable effect on the wear performance of15-5PH steel. Solution temperature too high or too low all will make the microstructure uniformity and decreases the wear resistance of15-5PH; In the condition of1040℃solution, from the ageing temperature450℃to600℃, with the ageing temperature increases, the hardness of the material gradually decreases, but its wear resistance increases first and then decreases. It’s proves that the wear resistance and hardness are not as absolute proportional relationship. When the material has good strength and good toughness, the wear resistance achieves the best state. The experiments indicate that15-5PH has the best wear resistance at the heat treatment of℃solution+480℃ageing.At room temperature, when the other experimental conditions are the same, with the load increases, the wear volume increases and the friction coefficient decreases; With the speed increases, the wear volume increases and the friction coefficient decreases. The main wear mechanism of15-5PH steel at room temperature is adhesive wear and particle wear.Compared with room temperature, at high temperature wear conditions, the wear surfaces of the tested samples have more serious adhesive and plastic flow traces, the energy spectrum can find that the wear surfaces and wear debris generate large amounts of oxygen. High temperature accelerates the oxidize of friction surface, thereby promoting the wear debris’ oxidation and adhesion, the wear surface forms a more serious oxide film and oxide particles. As the temperature increases, the friction coefficient increases gradually, the wear volume increases too. The main wear mechanism of15-5PH steel at high temperature is adhesive wear and oxidative wear.