Influence of alloying elements on gas nitriding process of high-stressed machine parts of weapons

Abstract

The chemical composition of the steel is one of the primary characteristics that influence the mechanical properties of high-stressed machine parts such as barrels of small arms weapon. Heat treatment is the most important technology to reach requested mechanical properties. By a suitable combination of mechanical and tribological properties, it is possible to improve the surface of highly stressed parts as to improve the wear resistance of barrel surface. Thus, surface technology is next step for obtaining new properties as tribological properties or preferable mechanical properties. Due to obtain suitable microstructure and wear resistance the samples of C35, 34Cr4, 37Cr4 and 42CrMo4 were heat-treated with following chemical heat treatment by gas nitriding process, for 6 hours. This paper deals with the influence of alloying elements of structural steels on surface microhardness and depth of diffusion layer. The gas nitriding process caused the creation of a compound layer on the surface of the steel. This layer leads to significant improvement in wear resistance. The concentration of alloying elements was analysed by OES methods. The technology of nitriding was applied to annealed, tempered and quenched steels. After chemical heat treatment, new surface morphology was created. The surface layers of the samples were analysed by microhardness method; surface morphology was evaluated by SEM method. Experimental part concerns structural steels with a concentration of alloying elements to 1 wt.%. In experimental part, the influence of alloying elements on the diffusion process in Fe-C system and the microhardness of the surface was proved.K e y w o r d s : gas nitriding, microhardness, chemical composition, diffusion, barrel

The influence of the post-weld heat treatment on the microstructure of Mangalloy – carbon steel clad-plate obtained by explosive welding

“…Wear resistance of materials can be improved in many ways, including chemical heat treatment, coating, cladding, and cold working (e.g., shot peening) [1,[4][5][6][7]. The obtained modification of material surface should provide good wear resistance, as well as coherency with the base material and low economic cost of the process [5,8,9]. One of the most promising technologies, which combines low cost and excellent properties of the product, is the explosive welding technique [10][11][12].…”

The Influence of the Post-Weld Heat Treatment on the Microstructure of Inconel 625/Carbon Steel Bimetal Joint Obtained by Explosive Welding

“…As it was mentioned previously, the potential solution of this problem is to clad steel P355NH with a layer of corrosion resistant material, e.g., Inconel 625, high-temperature creep resistant nickel alloy which is characterized by high resistance to oxidizing and reducing environment as well as pitting and crevice corrosion and it also displays tolerance to a wide range of the operating temperature (from −150 • C to 982 • C) [7]. Materials cladding or modifying their surface layer are widely used technologies in the production of industry equipment and machinery, but not all of this process can provide sufficient properties in terms of the formability of the cladded material [8][9][10]. The technology which allows to produce such bimetal clad-plate and provide both high quality of joint and formability is the explosive welding technique [11][12][13][14].…”

Application of Linear Optimization on Parameters of 3D FDM Print

“…The frequent requirement is cutting the costs on the 3D print and keeping the demanded quality parameters at the same time as known in case of special parts of high-stressed parts, esp. of ball screws [17,18]. In terms of the 3D printing costs, the costs of operating, the production equipment maintenance and material costs are significant [19,20].…”