Various carbonitriding processes have been applied to low-carbon steel. The carbon and nitrogen contents in the case of carbonitrided low-carbon steels have been evaluated, and their influences on microstructure, distortion, hardness, and strength have been investigated. The factor limiting the ferrite and pearlite formations with increasing nitrogen content was a mechanism that resulted in more retained austenite in the case of low-carbon steel treated using a high flow rate of ammonia. The high-nitrogen content and high amount of retained austenite in the case of carbonitrided low-carbon steel slightly reduced the hardness, case depth, and strength. However, the elongation was improved, and the distortion was reduced. In the case zones, fractures occurred along the grain boundaries, i.e., intergranular fractures, whereas the fracture surfaces in the core regions were typical ductile fractures, i.e., dimples were observed.

Effects of Carbon and Nitrogen on the Microstructure and Mechanical Properties of Carbonitrided Low-Carbon Steel

Weld techniques give powder metal a different dimension

Powder metallurgy (PM) technology is an ideal manufacturing process to produce near net shape parts i.e. part that requires little or no machining, examples of PM processes are spark plasma sinteri...

The synergy between powder metallurgy processes and welding of metallic alloy: a review

Stainless steel (SS) powders are used in the preparation of sintered SS products. One of the applications of sintered SS products is as filters in the petrochemical and food processing industries. In these industries, the SS filters are subject to severe conditions associated with the removal of solid particles from the fluid. Hence, SS filters should have adequate mechanical strength and high corrosion resistance. Welding can be used to manufacture SS filters. In this study, sintered AISI 316L specimens were welded using the TIG (Tungsten Inert Gas) process. The weld joints were examined by optical microscopy and by scanning electron microscopy. Electrochemical polarization measurements were carried out to evaluate the influence of welding on the corrosion resistance of sintered filters.

Jack A. Hamill

Papers

Fusion Welding P/M Components for Automotive Applications