A Light-Weight Achievement
It’s the same cost, same production line, but better performance. The goal is to develop lightweight automotive steel that has much better properties and is easy to use in industrial production.
Parts in red can be made by high-strength lightweight steels
Carmakers around the world are trying to reduce the weight of their vehicles to help offset environmental and fuel usage impacts. Work by Dr Mingxin Huang of the Department of Mechanical Engineering has helped to move them towards that goal.
Working with Baosteel Group, one of the largest steel providers in the world, and General Motors, he modified a known but previously-unworkable method for making strong thin steel into an application that was ready to use with existing production lines and reduced the weight of the steel by 20 per cent.
“It’s the same cost, same production line, but better performance,” he said. “Using existing production lines makes it easier for quicker application. Otherwise it costs billions of dollars in investment to change lines.”
Dr Huang got involved in this project after being approached by Baosteel. The firm had encountered difficulty in adopting a steel-making process invented in the US in 2003 that heats the steel to 900 degrees Celsius then quickly cools it to 180 degrees Celsius to create a single crystal structure. While the process worked well in the laboratory, it was not working in the steel plant where steel sheets are hundreds of metres long.
Dr Huang pinpointed the problem to the cooling process and tried heating the steel to a lower temperature and cooling it more slowly. This produced two crystal structures, but the steel was still thinner and as strong as conventionally-produced steel – meaning it could withstand crashes and compressions (the steel in question is used to build the skeleton of the car body). The findings were published in 2013.
Baosteel began to produce steel using this method almost immediately and has seen output rise exponentially from 414 tonnes in 2014 to 10,000 - 15,000 tonnes this year. The steel is mostly used by carmakers in Mainland China and Japan.
General Motors was also involved in the study and in 2015 rolled out the first car using the steel, the Chevrolet LOVA RV.
Dr Huang is continuing to work with Baosteel and has just started a major project looking at “Q&P” (for quenching and partitioning) steel, which has higher strength meaning thinner parts can be used. He has been investigating this steel for more than a decade, including doing projects with another major steel maker, Ansteel Group. “The goal is to develop steel that has much better properties and is easy to use in industrial production,” he said.
Dr Mingxin Huang of the Department of Mechanical Engineering received the Faculty Knowledge Exchange Award 2017 of the Faculty of Engineering for the project ‘High-strength Lightweight Steels for Low Emission Automobiles’.