Laser heat treatment as a method of improving corrosion resistance of steel 40Х9С2

Author(s):  
E.V. Shlyakova
2013 ◽  
Vol 712-715 ◽  
pp. 403-406
Author(s):  
Li Yuan Niu ◽  
Yi Chang Su ◽  
Zi Mu Shi ◽  
Ji Xing Lin ◽  
Guang Yu Li

An Al coating and black passive film technique was developed in this research. Meanwhile, a fine and uniform Al coating with good binding force on steel surface was prepared. And a black passive film was used as a post-treated film of the electroplated Al coating. The result proves that the corrosion resistance of electroplated Al coating was over one time higher than that of zinc coating by black passivation. Besides, Al coating was less brittle with good ductility and, it could be used as a pretreatment layer before conducting laser heat treatment to significantly improve the efficiency of laser heat treatment.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Hui Gon Chun ◽  
Tong Yul Cho ◽  
Jae Hong Yoon ◽  
Gun Hwan Lee

High-velocity oxygen-fuel (HVOF) thermal spray coating with WC-metal powder was carried out by using optimal coating process on an Inconel718 surface for improvement of the surface properties, friction, wear, and corrosion resistance. Binder metals such as Cr and Ni were completely melted and WC was decomposed partially to W2C and graphite during the high temperature (up to 3500°C) thermal spraying. The melted metals were bonded with WC and other carbides and were formed as WC-metal coating. The graphite and excessively sprayed oxygen formed carbon oxide gases, and these gases formed porous coating by evolution of the gases. The surface properties were improved by HVOF coating and were improved further by CO2laser heat treatment (LH). Wear resistance of In718 surface was improved by coating and LH at 25°C and an elevated temperature of 450°C, resulting in reduction of wear trace traces, and was further improved by LH of the coating in reducing wear depth. Corrosion resistance due to coating in sea water was improved by LH. HVOF coating of WC-metal powder on a metal surface and a LH of the coating were highly recommended for the improvement of In718 surface properties, the friction behavior, and wear resistance.


2021 ◽  
Vol 6 (1 (114)) ◽  
pp. 72-80
Author(s):  
Oleksandr Danyleiko ◽  
Vitaliy Dzhemelinskyi ◽  
Dmytro Lesyk

A technique is presented for hardening metal products, in particular, the main tools (hammers) and cases of core drilling bits made of steel 30HGSA, using thermomechanical surface treatment according to a separate scheme. The method of combined laser thermomechanical hardening used in the study consists in the use of shot peening followed by laser heat treatment. Its use makes it possible to increase the operational properties of steel products, in particular, their wear and corrosion resistance. Based on the results of theoretical and experimental studies, the paper substantiates the features of dynamic surface plastic deformation for the analysis of impact during shot peening. The advantages of using laser hardening without surface melting are presented. Experimental research methods are proposed for determining the structural-phase composition, structure of the surface layer, hardness and microhardness of the hardened zones of steel 30HGSA. The range of rational modes of impact shot peening and thermal laser treatment has been determined. A device for testing samples for wear resistance has been developed. Methods of testing for wear and corrosion resistance of the surface of samples are proposed for assessing the tribological properties and contact interaction of materials under quasi-static and dynamic loading conditions. It is concluded that rational technological modes of hardening tools made of steel 30HGSA using combined laser thermomechanical treatment allow increasing the depth of the hardened layer by ~1.5 times compared to laser heat treatment. In addition, they provide the microhardness of the surface layer of ~5400 MPa, which is ~2.5 times higher than the microhardness of the base material


Author(s):  
Rachid Fakir ◽  
Noureddine Barka ◽  
Jean Brousseau

This paper presents a numerical model able to control the temperature distribution along a 4340 steel cylinder heat-treated with Nd: YAG laser. The numerical model developed using the numerical finite element method, was based on a study of surface temperature variation and the adjustment of this temperature by a control of the heat treatment laser power. The proposed analytical approach was built gradually by (i) the development of a numerical model of laser heat treatment of the cylindrical workpiece, (ii) an analysis of the results of simulations and experimental tests, (iii) development of a laser power adjustment approach, and (iv) proposal of a laser power control predictor using neural networks. This approach was made possible by highlighting the influence of the fixed (non-variable) parameters of the laser heat treatment on the case depth, and has shown that it is possible by controlling the laser parameters to homogenize the distribution of the maximum temperature reached on the surface for a uniform case depth. The feasibility and effectiveness of the proposed approach leads to a reliable and accurate model able to guarantee a uniform surface temperature and a regular case depth for a cylindrical workpiece of a length of 50-mm and with a diameter of between 16-mm and 22-mm.


2010 ◽  
Author(s):  
Byungki Jung ◽  
Jing Sha ◽  
Florencia Paredes ◽  
Christopher K. Ober ◽  
Michael O. Thompson ◽  
...  

2019 ◽  
Vol 743 ◽  
pp. 294-300 ◽  
Author(s):  
Kun Wang ◽  
Aiping Wei ◽  
Zimu Shi ◽  
Xizhang Chen ◽  
Jixing Lin ◽  
...  

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 379 ◽  
Author(s):  
Wei Zhang ◽  
Tao Jiang ◽  
Jing Li ◽  
Liqiang Liu

The effects of laser heat treatment on the microstructure and properties of alloy 800H were investigated. The fracture morphology, elemental changes, and phase composition of the specimens were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffractometry (XRD). The results show that the long-lasting life of the specimen after laser heat treatment increased by 28.6%, and the elongation after fracture increased by 20.7%. The macroscopic morphology of the fracture specimen exhibited obvious ductile fracture morphology, and the changes in the elemental content and grain size significantly affected the ductility and toughness of the alloy. This study has certain guiding significance for the optimization of the heat treatment process of this type of alloy.


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