TITLE:
Modification of Steel Surface Using the Laser Energy Olga Chudina
AUTHORS:
Olga Chudina
KEYWORDS:
Laser Alloying, Nitriding, Metallization, Diffusion Layer
JOURNAL NAME:
Journal of Surface Engineered Materials and Advanced Technology,
Vol.4 No.4,
June
13,
2014
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.