Kinetics of atmospheric corrosion of mild steel, zinc, galvanized iron and aluminium at 10 exposure stations in India

Corrosion behavior of metals and alloys in marine-industrial environment

“…Many environmental changes have occurred due to industrialization, population growth and climatic changes. A new corrosion map of India is being prepared by the Central Electrochemical Research Institute, Karaikudi, India, and some data have already been published [34][35][36][37][38][39].…”

Inversed Phosphorus Segregation in Twin Roll Cast Strips for Improvement of Mechanical Properties and Weathering Resistance

“…If the value of n is greater than 0.5, it indicates that there are cracks in the rust to accelerate the corrosion process, while the value of n smaller than 0.5 indicates that the diffusion process is blocked due to the formation of dense layer in the rust. 30) In the first 60 cycles, the values of n for both strips were regressed to be about 0.60, indicating that cracks had been formed in the rusts at the early stages of corrosion. In the last 60 cycles of the corrosion exposure, the value of n was regressed to be 0.46 for the 0.08P HCA strip, showing that the corrosion process was controlled by diffusion.…”

“…The values of n for both 0.15P and 0.26P TRSC strips, however, were only half of 0.5, implying that dense layers could have been formed at the interfaces between rusts and substrates to block the diffusion. 30) According to the ternary Fe-P-O phase diagram, the critical P concentration in steel for the formation of phosphate is greater than 0.24 % by weight, 31) implying that the bulk concentration of P in a conventional slab must be higher than this value if the steel is to be weathering resistant, which could deteriorate the mechanical properties due to severe central segregation. In the present work, it has been shown by the accelerated corrosion tests that phosphate enriched layers could have been formed beneath corrosion scales on 0.15P the TRSC strip, and the scale thickness was reduced by about 60 % as compared with the HCA strip with 0.08 % P. As indicated by the quantitative analysis, the P concentration near the surfaces of the 0.15P TRSC strip was measured to be higher than 0.24 % by weight, being just enough for the formation of phosphate enriched layer between corrosion scale and substrate during corrosion exposure.…”

Correlation Studies between Outdoor Exposure and Accelerated Laboratory Corrosion Tests for Galvanic and Non-Galvanic Ceramic-Aluminum Couples

“…This kind of model is usually good in predicting the corrosion rate over a period time for various atmospheric conditions. Natesan et al [95] mapped India by exposing mild steel, galvanized iron and Al at 10 different test sites. The k and n values were obtained using linear regression and the 10 different test sites were ranked based on their corrosivity index.…”