Anticorrosion nitrided layers on unalloyed and alloyed steels

4th International Conference Recent Trends in Structural Materials

Wach, P.^1 ; Michalski, J.^1 ; Burdyski, K.^1 ; Ciski, A.^1

Institute of Precision Mechanics, Duchnicka 3 St., Warsaw

01-796, Poland^1

关键词: 42crmo4 steels;    Anti-corrosion;    Controlled gas nitriding;    Corrosion property;    ELectrochemical methods;    Neutral salt spray;    Salt spray chambers;    Unalloyed steels;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/179/1/012069/pdf
DOI  :  10.1088/1757-899X/179/1/012069

来源: IOP

【 摘 要 】

In the paper, nitrided layers on unalloyed and alloyed steels and their corrosion properties are presented. Nitrided layers in the controlled gas nitriding process on C10 and 42CrMo4 steels were formed. Two types of nitrided layers are presented: with nitride iron layers above and below 15 μm. Nitrided layer with nitride layer above 15 μm has good corrosion resistance, but after nitriding of machine parts were subsequently oxidised and impregnated. In the second type of nitrided layer, the surface layers of iron nitrides had a thickness of 3.0 to 11.0 μm. Nitrided layers with a surface layer of iron nitrides with the γ' (Fe4N) structure were formed on unalloyed steel and investigated. The so-formed layers were subject to basic metallographic, X-ray diffraction and corrosion resistance studies carried out by electrochemical methods and in a neutral salt spray chamber. It was found that the layers consisting only of γ' phase had a good corrosion resistance. Necessary requirements for achieving an enhanced resistance comprise their complete tightness and thickness not lower than 9.0 μm. Thinner layers had good electrochemical properties but did not exhibit corrosion resistance in the salt spray chamber.