Low use of galvanised steel speeds up car corrosion

Lesser usage of galvanised steel in cars for domestic consumption is leading to faster corrosion in vehicles used in coastal areas. Automobile manufacturers are using lesser quantum of galvanised steel in cars meant for the domestic market compared to those produced for the export market.

The studies done by IIT Bombay on hatchback and some of the sedan cars in Mumbai and Chennai have shown that higher usage of uncoated steel in the body parts of cars increases the incidence of visible perforations, paint blisters, and surface red rust within five years of use. With Indians spending nearly 12 hours more of their time behind wheels on an average every day, there is a higher risk of life due to corrosion, the study found.

Corrosion mainly occurs due to higher levels humidity and chloride content in the air in coastal areas. Cars with higher galvanised steel content took around 10 years to corrode. Vehilces used in interior areas with lesser humidity too had higher life.

 “The study is an eye-opener for car owners as it clearly indicates the causes for imperfection that arise owing to climatic conditions. Currently, there is almost zero awareness about how these imperfections over the years grow into life-threatening hazards for car owners and we are confident that this study will create an impact by creating the desired awareness among the public,” said Anand Khanna, former professor, department of metallurgy engineering, IIT – Bombay, who spearheaded the survey in Chennai. International Zinc Association also participated in the survey which was completed recently. IIT Bombay had conducted the study in Mumbai cars costing less than Rs 10 lakh in 2015 and had found similar results, indicating that the phenomenon is prevalent across the coastal belt of the country. 

On an average, Indian car manufacturers use about 20-25 per cent galvanised steel for the vehicles manufactured and sold in the domestic market. However, the same Indian car manufacturers use over 70 per cent galvanised steel for the same models they export to markets in Europe, Asia and Africa and produced from the same stamping and assembly facilities.

“The car companies are not presently using galvanised steel for the domestic market because Indian consumers are not demanding it. In India they use it only in the chassis, while it is used all over the body in costlier cars and those meant for exports. A car would cost only Rs 5,000 to Rs 8,000 more by replacing uncoated steel with galvanised steel. Considering the safety issues and life of the vehicle, this is not a big cost,” said Khanna.