Surface hardening method for martensite stainless steel

Abstract

The invention relates to a surface hardening method for martensite stainless steel. In the technical scheme, the surface hardening method comprises the following steps of: putting a processed martensite stainless steel workpiece on a workbench of a vacuum chamber of an ion implanter, vacuumizing until the pressure is between 2.0*10<-3> and 3.0*10<-3>Pa, and removing a passivation layer on the surface of the workpiece by using an ion cleaning source; and implanting nitrogen ions to the martensite stainless steel workpiece of which the surface passivation layer is removed under the conditions that: the vacuum degree is between 5.0*10<-4> and 5.0*10<-2>Pa, the accelerating voltage of the ion source is between 10 and 100 kV, and the implantation dose is between 5.0*10<15> and 5.0*10<19> ions / centimeter<2> to obtain the surface-hardened martensite stainless steel, wherein the operating conditions of the cleaning source include: filament current is between 6 and 10 A, arc voltage is between 40 and 70 V, extraction voltage is between 0.6 and 1.5 kV, and extraction current is between 40 and 70 mA. The surface hardening method has the characteristics of simple process and no pollution in the processing process; and the abrasion performance and hardness of the surface of the product processed by the method are improved substantially, the combination between a hardening layer and a stainless steel substrate is firm, and the service life is long.

Description

technical field [0001] The invention belongs to the technical field of surface hardening. Specifically relates to a method for surface hardening of martensitic stainless steel. Background technique [0002] Martensitic stainless steel has high strength and corrosion resistance, so it has been widely used in industrial production. It can be used to manufacture machine parts such as steam turbine blades (1Cr13), steam equipment shafts and tie rods (2Cr13), and parts working in corrosive media such as valves, bolts, etc. (4Cr13); alloy steel with high carbon content (4Cr13 , 9Cr18) are used in the manufacture of medical equipment, table knives, measuring tools, springs, etc. However, since the surface hardness of martensitic stainless steel is not high, scratches are easy to occur on the surface during use, and the wear resistance is poor, which affects the service life. In order to overcome these problems, stainless steel is usually nitriding, carburizing or carbonitriding ...

AI Technical Summary

Problems solved by technology

[0006] Although the above surface treatment methods can change the surface characteristics of stainless steel and improve its service life, the disadvantages are: ① the high temperature treatment process causes deformation of the workpiece, and the low vacuum degree during work causes surface oxidation; ② heat treatment and carburizing treatment cause surface deformation of the workpiece. The appearance changes, which affects the precision and surface finish of the workpiece; ③ There are many conditions that need to be controlled for infiltration, and the infiltration amount of carbon and nitrogen is not easy to control, which affects the quality of the product; ④ It takes a long time to remove the passivation layer, the process is complicated, and the use of halogen gas , strong acid, etc. cause serious pollution to the environment