Corrosion tests in artificial atmospheres. Salt spray tests

2012 ◽  
Keyword(s):  
2016 ◽  
Vol 60 (2) ◽  
pp. 46-49
Author(s):  
T. Prošek

Abstract Accelerated corrosion testing is indispensable for material selection, quality control and both initial and residual life time prediction for bare and painted metallic, polymeric, adhesive and other materials in atmospheric exposure conditions. The best known Neutral Salt Spray (NSS) test provides unrealistic conditions and poor correlation to exposures in atmosphere. Modern cyclic accelerated corrosion tests include intermittent salt spray, wet and dry phases and eventually other technical phases. They are able to predict the material performance in service more correctly as documented on several examples. The use of NSS should thus be restricted for quality control.


2021 ◽  
Author(s):  
Venkatesh R ◽  
S Manivannan ◽  
Kumaresh Babu S P

Abstract Weathering steel, a low carbon alloy steel, most widely used in marine transportation and construction fields like bridges, sculptures where corrosion resistance is the main concern. Weathering steel creates an adhering protective coating on its surface in the right environmental conditions. The protective layer which is formed on the surface weathering steel known as patina. It protects the structure from further corrosion to occur. When these weathering steels are continuously exposed to moisture environment its corrosion resistance decreases. So, our investigation deals about the studies of the coatings used on weathering steel to increase its corrosion resistance in marine conditions. The coatings applied on the substrate were poly urea, polyurethane, epoxy and black enamel. Corrosion tests were performed on these coated samples to evaluate their corrosion behaviour in different environments. Corrosion tests that were performed are immersion test, salt spray test and potentio-dynamic test. The profilometry test is investigated and it confirmed the depth of the corrosion on the coatings. Based on the corrosion studies, we conclude that poly urea is the excellent coating followed by polyurethane, black enamel and epoxy.


2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Ashok Kumar M ◽  
Thirumalaikumarasamy D ◽  
Paventhan R ◽  
Thirumal P

An investigation was carried out to quantify and characterize the corrosion behaviour of AZ31B magnesium alloy joints. Extruded Mg alloy plates of 6 mm thick of AZ31B grade were butt welded using a solid state, environmentally cleaner welding process, friction stir welding process. The weld specimens were underwent immersion, salt spray, pitting and galvanic corrosion tests in order to quantify and characterize the corrosion rates of the welds with the influence of different pH values, chloride ion concentration and the corrosion time. The corrosion rates, microstructure, scanning electron microscopy and X-ray diffraction analysis concludes the optimum parameter for the usage of the magnesium alloy welds for the best service applications. Keywords: Keywords: EDM, Alumina and Genetic Algorithm


2021 ◽  
Vol 63 (2) ◽  
pp. 151-156
Author(s):  
Lihua Gong ◽  
Weimin Guo ◽  
Feng Pan

Abstract The influence of metal inert-gas arc welding (MIG) on the corrosion behavior of 6061-T6 aluminum alloy in a simulated tropical marine atmospheric environment (related to high temperature, high humidity and high salt spray) were examined by dry-wet alternate immersion corrosion tests. The equivalent conversion was used to design the accelerated test time. The results show that in the initial stage, the intermetallic compound, rich in Fe, Si and Cu, had little influence on corrosion resistance in the heat-affected zone. For a corrosion time of 3 days in a tropical marine atmospheric environment, the corrosion rate of the welded joint increased rapidly, even reaching 3.5 times that of the base metal. Though the corrosion products had significant impact on slowing down the corrosion rate, as with the base metal, the corrosion rate of the welded joint was nearly double that of the base metal during the longest cycle period involving alternate immersion corrosion tests for 20 days.


Sign in / Sign up

Export Citation Format

Share Document