Corrosion wear of BW450 martensitic wear-resistant steel in 3.5wt% NaCl slurry containing high concentration of quartz s

Corrosion and wear are two of the most common and destructive damage mechanisms of mechanical components used in marine, off-shore and industrial applications. The combination of corrosion and wear intensifies the degradation of metallic components resulting in premature failure and capital loss. Therefore, it is crucial to determine the corrosion wear of components used in such harsh environments.
    
The martensitic wear-resistant steel (MWRS) grade BW450 was investigated for its corrosion wear behavior in a laboratory-scale test using a 3.5wt% NaCl slurry containing a high concentration of quartz sand. The steel grade was selected due to its well-known high wear-resistance and good corrosion resistance behavior. In this article, the influence of the corrosive environment on the wear rate is highlighted and the tribological performance of the steel grade is discussed.
   
Microstructure of martensitic wear-resistant steel (MWRS) grade BW450.
    
Materials & Methodology
The martensitic wear-resistant steel (MWRS) grade BW450 was used for the laboratory-scale test. The microstructure of the steel is shown in Figure 1.
    
The test was implemented in a 3.5wt% NaCl slurry containing high concentration of quartz sand. The slurry was prepared in a specified concentration and pH according to the ASTM G93 Standard. The test was run for 100 hours and the wear rate of the steel was calculated from the weight loss of the specimens.
    
Results & Discussion
The results for the corrosion wear of the BW450 steel in the 3.5wt% NaCl slurry containing a high concentration of quartz sand show a steady wear rate of 0.05 mm/hr. This steady wear rate occurs despite the aggressive chemical attack present during the test. This suggests that the corrosion/abrasion damage mechanism is predominant as opposed to the wear caused by abrasion and friction. The chemical attack leads to the dissolution of surface elements and an increase in surface roughness. This in turn leads to an increase in friction and wear.
    
Wear rate of martensitic wear-resistant steel (MWRS) grade BW450 in a 3.5wt% NaCl slurry containing high concentration of quartz sand.
    
Conclusion
The laboratory-scale test to investigate the corrosion wear of martensitic wear-resistant steel (MWRS) grade BW450 in a 3.5wt% NaCl slurry containing a high concentration of quartz sand has shown that the corrosion wear rate of the steel is steady, despite the aggressive environment. The wearing behavior is mainly caused by chemical attack which leads to an increase in friction and consequent wear.
    
The wear-resistant performance of the steel grade is providing acceptable service life, even in aggressive environments where corrosion is dominant. This demonstrates the capability of the material to maintain its properties as well as to improve the service life of components operating in harsh environments.

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