Modification of Steel Surface Using the Laser Energy Olga Chudina

Olga Chudina

Moscow Automobile and Road Construction State Technical University (MADI), Moscow, Russia.

DOI: 10.4236/jsemat.2014.44021                

Abstract

The article is devoted to surface hardening of steels by alloying with the use of laser energy. Two combined technologies were proposed: first—laser alloying by nitride-forming elements followed by nitriding, and second—the local laser alloying followed by metallization in atmosphere of ammonia. It is shown that laser alloying in continuous radiation forms a layer with a homogeneous fine-grained structure with thickness of 600 microns. The subsequent nitriding increases the microhardness of the surface layer of low-carbon steels to 20,000 MPa, increases wear-resistance in a 3 - 15 times and crack resistance in a 1.5 times. Two-stage technology of metallization allows getting diffusion layer on the surface of steels with the thickness, which is 1.5 - 2 times higher than after traditional metallization. In addition, this method of surface modification can significantly reduce the temperature of diffusion metallization and reduce the processing time to 3 hours. The optimal regimes of both technologies, which provide homogeneous multiphase diffusion layers with high hardness and wear resistance, were determined.

Keywords

Laser Alloying, Nitriding, Metallization, Diffusion Layer

Conflicts of Interest

The authors declare no conflicts of interest.

References

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