Research Of Austenitic Stainless Steel Low Temperature Plasma-Gas Recombination Hardening Treatment

To compensate for the lack of a single low temperature austenitic stainless steel surface hardening treatment, overcoming the defects that it is difficult for low temperature gas hardening treatment to remove the stainless steel passive film and that the temperature of sample is not homogeneous when using low temperature plasma carburizing. In this paper, adopting austenitic stainless low temperature plasma-gas recombination hardening new technology. First, with H ion bombardment sample to remove the passive film of austenitic stainless steel and improve surface active. Then close the DC glow discharge power supply, passing into the blended gas of H2+CO, treating the sample with low temperature gas carburizing at low press. In order to keep the surface active of sample and increase the speed of carburizing, adopting the process of ion bombardment and gas carburizing multiple cycles at low temperature, the purpose is to obtain thick and high corrosion resistance hardened layer. The test results show that in the critical temperature range during which the corrosion resistance does not reduce, as the carburizing temperature rises, the surface hardness of stainless steel and the thickness of carburized layer also rises; Increasing the process cycle also can improve the hardness and thickness of the surface of austenitic stainless steel.Austenitic stainless steel after low temperature plasma-gas processing complex, the stainless steel surface hardness, wear resistance, fatigue strength has increased significantly.In this paper, studying the austenitic stainless steel low temperature plasma-gas complex treatment process, its process and theory was made a systematic research. It was discussed about the effect of proportion of H2:CO, gas pressure and time of ion bombardment on the carbonized layer.The results show that the low temperature carburization temperature is lower than 550℃, the heating temperature is higher than the austenitic stainless steel causes precipitation of chromium carbides, the compound constituting the electrochemical corrosion of the stainless steel substrate, thus reducing the corrosion resistance of stainless. Within the scope of the test period, the number of cycles increases ion bombardment and the cycle gas carburizing process can improve the surface of hardness and thickness of austenitic stainless steel.Orthogonal design method of austenitic stainless steel low temperature plasma-gas complex hardening process parameters were optimized, and the orthogonal experiment to optimize the process parameters prediction was verified. Integrated thickness and hardness of the two indicators, austenitic stainless steel cold plasma-gas complex hardening process optimization of process parameters: carburizing temperature is 500℃, carburizing cycle 6T; H2:CO = 1:5, the gas pressure is-0.04MPa; ion bombardment time of 30 min.