Effects of tungsten carbide thermal spray coating by HP/HVOF and hard chromium electroplating on AISI 4340 high strength steel


Autoria(s): Nascimento, Marcelino P; Souza, Renato C; Miguel, Ivancy M; Pigatin, Walter L; Voorwald, Herman J.C
Contribuinte(s)

Universidade Estadual Paulista (UNESP)

Data(s)

27/05/2014

27/05/2014

16/04/2001

Resumo

In cases of decorative and functional applications, chromium results in protection against wear and corrosion combined with chemical resistance and good lubricity. However, pressure to identify alternatives or to improve conventional chromium electroplating mechanical characteristics has increased in recent years, related to the reduction in the fatigue strength of the base material and to environmental requirements. The high efficiency and fluoride-free hard chromium electroplating is an improvement to the conventional process, considering chemical and physical final properties. One of the most interesting, environmentally safer and cleaner alternatives for the replacement of hard chrome plating is tungsten carbide thermal spray coating, applied by the high velocity oxy-fuel (HVOF) process. The aim of this study was to analyse the effects of the tungsten carbide thermal spray coating applied by the HP/HVOF process and of the high efficiency and fluoride-free hard chromium electroplating (in the present paper called 'accelerated'), in comparison to the conventional hard chromium electroplating on the AISI 4340 high strength steel behaviour in fatigue, corrosion, and abrasive wear tests. The results showed that the coatings were damaging to the AISI 4340 steel behaviour when submitted to fatigue testing, with the tungsten carbide thermal spray coatings showing the better performance. Experimental data from abrasive wear tests were conclusive, indicating better results from the WC coating. Regarding corrosion by salt spray test, both coatings were completely corroded after 72 h exposure. Scanning electron microscopy technique (SEM) and optical microscopy were used to observe crack origin sites, thickness and adhesion in all the coatings and microcrack density in hard chromium electroplatings, to aid in the results analysis. © 2001 Elsevier Science B.V. All rights reserved.

Formato

113-124

Identificador

http://dx.doi.org/10.1016/S0257-8972(00)01148-8

Surface and Coatings Technology, v. 138, n. 2-3, p. 113-124, 2001.

0257-8972

http://hdl.handle.net/11449/66497

10.1016/S0257-8972(00)01148-8

2-s2.0-0035897255

Idioma(s)

eng

Relação

Surface and Coatings Technology

Direitos

closedAccess

Palavras-Chave #Abrasive wear #Corrosion #Fatigue #Hard chromium electroplating #HP/HVOF #Tungsten carbide thermal spray coating #Chemical resistance #Chromium #Coatings #Fatigue testing #Optical microscopy #Scanning electron microscopy #Tungsten #Wear of materials #Abrasive wear test #Tungsten carbide thermal spray coatings #Electroplating #coating #corrosion #electroplating #fatigue #spray #tungsten carbide
Tipo

info:eu-repo/semantics/article