Evaluation of Joining Performance of Different Coated Steel Sheets Used in Automotive Applications

<div class="section abstract"><div class="htmlview paragraph">To meet the corrosion target of automotive vehicles, different coated steel sheets are used in various parts of the body in white (BIW), chassis, and powertrain. Hot dip galvanized (GI) and hot hip galvannealed (GA) are the two most commonly used steel sheets worldwide. Other coatings, such as Zn-Ni, Al-Si, Zn plating, and electro-galvanized zinc coating, are application-specific coatings that are used suitably to meet different performance requirements. To meet the robust corrosion and performance requirements, there is a trend of increasing the use of coated steel sheets in automotive vehicles. While different coated steels have different corrosion performance, they also exhibit different joining and paint adhesion performance. Spot welding is one of the most common technique used for joining automotive parts. Joint strength majorly depends on steel base material grade, chemistry and properties. However, coating on base material also influence joining performance. Major challenge is faced when different coated steel is used in same joint. Joint strength ultimately contributes to vehicle’s durability and crash performance, hence play a very important role. It is very important to know the characteristic and joint performance of different coated steel under different joint combinations. This paper discusses joining of different combination of GA, GI and bare steel, identification of suitable joining parameters & process, study of mechanical properties & microstructural characterization of joint.</div></div>