放電浸炭の特性

抄録

The purpose of this paper is to clarify the character of spark carburization for iron, and characteristics of the spark carburized layer which is not found in other carburizing treatments, and also to investigate the effect of superposing magnetic field and high frequency current. Through microscope and by X-ray diffraction, the following conclusions have been drawn:
(1) Glycerine-25% Potassium acetate is extremely excellent for the carburizing solution, and the caburized layer of 0.2∼0.5 mm can be obtained by 5∼10 min carburization.
(2) As for the structure of the carburized quenching layer, the surface shows structure including carbide, residual austenite and martensite, and moreover the inner part shows a martensite structure like fine needles. This is because the surface layer contains a large amount of carbon, and from this it can be estimated that the mechanical properties, especially wear resistance, is excellent.
(3) In the carburization the high frequency current has the effect of unifying diffusion. In this case, the frequency of 350 KHz is effective. The magnetic field has the effect of increasing the carburizing ability by 50∼80% on the surface in parallel with the magnetic flux.