It is a common practice that a normalizing is performed between hot forging and carburizing to make carburized steel parts for car use. Here, the austenite grain growth behavior on carburizing was investigated, in the case where the austenite (γ) γ-ferrite (α) transformation was completed after hot forging and a normalizing was carried out, and in the case of performing the normalizing without completing γ-α transformation after hot forging. We clarified that the grain growth of the former was smaller than that of the latter, comparing those behavior from viewpoint of α grain size and precipitation of AlN precipitate before carburizing.

The effect of the intermetallic compound layer formed by atmospheric-controlled induction heating fine particle peening （AIH-FPP） treatment on the wear resistance and high-temperature oxidation resistance of titanium alloys was investigated. To form an intermetallic compound layer on a titanium alloy by AIH-FPP treatment, pure titanium, aluminum, and nickel particles were mechanically milled using a planetary ball mill, and the prepared particles were used as shot particles in the AIH-FPP treatment. The results showed that intermetallic compound layers, consisting of Ti₃Al and Ti₂NiAl₃, were formed on titanium alloy by AIH-FPP treatment using the prepared particles. The wear resistance and high-temperature oxidation resistance of the AIH-FPP treated specimen were higher than those of the untreated ones.

By using a low temperature plasma carburising process combined active screen and DC plasma methods at 773 K under an atmosphere of CH₄／H₂ gas mixture, an expanded-austenite phase （called the S phase） that has both high hardness and high resistance to corrosion can be efficiently formed at the surface of austenitic stainless steels. In this paper, effects of the S phase formed in SUS304 and 316 steels on microstructure, tension, and oscillation wear properties were investigated by optical microscopy, x-ray diffraction （XRD） analysis, transmission electron microscopy （TEM） observation, a tensile test, and reciprocating ball-on-disc tribometer （SRV） test. The results show that the S phase includes high-density dislocations, has a high amount of twins and stacking faults, and improves tensile strength while decreasing the elongation. The S phase was also found to improve frictional wear and fretting wear resistances of austenitic stainless steels.