Automotive applications

This document compiles information about the Next Generation Vehicle (NGV) project “Stainless steel for lightweight automotive applications”, which was pursued by a consortium of European stainless steel producers, automotive manufacturers and other industrial partners specializing in tooling, coatings and numerical modeling. Stainless steel – specifically work-hardened material in the tensile strength levels C800 and C1000 – are considered for applications in B-pillars, bumper beams, rollover bars, crash boxes, suspensions, wheel housings and subframes. Testing included grades: the manganese austenitic stainless steel 1.4376, the chromium-nickel austenitic stainless steel 1.4318 – a classic in rail applications – and the lean duplex stainless steel 1.4162. In respect of tooling, punch and blank holder forces were identified. Further objects of the investigation included the interaction of the workpiece with the tools – usually coated with TiAlN, AlCrN and TiC -, as well as the influence of lubricants. Research into the welding properties led to the conclusion that a combination of spot-welding and bonding performed particularly well. Also mixed-material tailored blanks were investigated. The B-pillar of a Volvo S40 was test-produced using stainless steels in deep-drawn and hydroformed variants. The component was then crash-tested and the results compared with those of simulations.

The demand for bigger, faster and lighter moving vehicles, such as ships, trains, trucks and buses has increased the importance of efficient structural arrangements. In principle two approaches exist to develop efficient structures: either application of new materials or the use of new structural design.
Source: Stainless Steel World

A short description of the various grades of stainless steel used in automotive applications. It has been written primarily from a European perspective and may not fully reflect the practice in other regions.

Stainless steel is widely used in car exhaust systems and for auto parts such as hose clamps and seatbelt springs. It will soon be common in chassis, suspension, body, fuel tank and catalytic converter applications. Stainless is now a candidate for structural applications.

One of the most promising areas for stainless steel in the automotive sector would seem to be in structural applications. This explains the launch at the end of 2004 of the “Next Generation Vehicle” project. The aim of the project was to demonstrate to the automotive industry that stainless steel can be used to reduce weight and cost in the manufacture of motor vehicles, and at the same time improve safety and sustainability in automotive body structures.
Source: Stainless Steel Focus

There is a growing interest for stainless steels in structural automotive applications. As a consequence, more questions are raised regarding the sensitivity of stainless steels to strain rate. This document attempts to summarize the published results for strain rates from 0,2 to 10%.
Source: Outokumpu