SONGKLANAKARIN JOURNAL OF SCIENCE & TECHNOLOGY

Volume 41, No. 03, Month MAY, Year 2019, Pages 539 - 544

Microstructural alteration and oxidation behavior of boronized stainless steel aisi 440c after heat treatments

Patcharin Naemchanthara and Patiphan Juijerm

Abstract Download PDF

The martensitic stainless steel AISI 440C was boronized at a temperature of 950 °C for about 4 hr. Heat treatments at a temperature of 850 °C for about 2-8 hr were performed to eliminate the FeB phase of the boride layer. The oxidation investigations were carried out at a given temperature of 900 °C on different surface conditions. It was found that the FeB phase was completely dissolved and transformed to the Fe2B phase after a heat treatment at a temperature of 850 °C for about 8 hr. The oxidation behavior of the non-boronized, boronized and boronized with heat treatment of 8 hr conditions exhibit a parabolic manner, while the specimens boronized with heat treatments of 2 – 6 hr show a linear manner. The single-phase (Fe2B) boride layer on the martensitic stainless steel AISI 440C possesses a lowest oxidation rate as compared to other investigated surface conditions

Keywords

oxidation resistance, thermochemical surface treatment, heat treatment, martensitic stainless steel, boronizing

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