The visual appeal of polished stainless steel is regularly used to good effect in enhancing the outward appearance of modern road vehicles of all types. Where quality and durability are the primary considerations, stainless steel is often chosen in preference to other metallic materials and coatings.

Less widely known, however, is the important functional role that stainless steel has to play in automotive construction which, in volume terms, greatly outstrips the market for decorative trim. Here, the unique properties of the material make it the optimum choice for unseen, but vitally important component parts. This is easily illustrated by selecting two out of many examples:

§         The material’s outstanding corrosion resistance provides a solution to the age-old problem of rotting exhaust silencers and catalytic converters. The problem is double-edged, as hot exhaust gases attack the inner surfaces while water, salt and general road dirt attack the exterior. Where carbon steel and various coatings have failed, stainless steel has provided the modern, cost-effective solution.

§         Significant future growth is foreseen in the use of stainless steel for key structural components in automotive construction. Due to its unique mechanical properties, stainless steel can add an extra dimension of passenger safety, especially in the way that a large part of the energy produced in a collision is absorbed as the material deforms under impact. This property is already put to good effect in the design of modern large passenger vehicles such as buses, but the future potential in all types of road vehicle is immense.

The publications in this section offer information on the practical, economic and safety advantages of using stainless steels in the field of automotive transport, one of the fastest-growing end-use sectors for the material.

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.

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.

Spot welded, adhesive bonded, weldbonded, laser welded and clinched joints of stainless steel sheets - a review of their fatigue properties.

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.

Filtration is part of our daily life … and stainless steel is the material of choice for filtration. In this animation you can find out how, why and where!

Silencer wool is used in automotive exhausts to reduce noise emissions from the vehicle. Stainless competes with glass and direct-cast metallic fibres in this application.

Hydrogen-powered cars will require high pressure (+700 bar) hydrogen tanks. The tanks must be reliable under all conditions and at temperatures ranging between -60 and +60° C.

Exhaust valves in combustion engines operate at high temperatures. However, the gas temperature of intake valves is much lower. This dictates the use of different stainless grades for the intake and exhaust valves. Stainless steel provides optimum performance at the lowest cost.

A short description by Tony Newson of Eurofer, of the various grades of stainless steel used in automotive applications.

This excerpt from the Book of New Applications 2009, gives more information on applications from the automotive sector.

The following are included here:

·         Motorcycle Exhaust System

·         Silencer Wool

·         Truck Protector

·         Bicycle Rim

·         Folding Moped and Bicycle

·         Vespa Silencer

Paper originally delivered at the BSSA Conference 'Stainless Solutions for a Sustainable Future' held in Rotherham on 3rd April 2003. This paper describes a study where 2 high strength austenitic stainless steels and 3 carbon steels used at Volvo Cars Body Components, were compared. Component stamping trials are described and analysed.

Significant petrol savings, longer service life, lighter tare weight and reduced maintenance costs are just a few features of Australia's first stainless steel bus.

This excerpt from the ISSF Book of New Applications 2006, gives more information on applications from the automotive sector.

Included here are a motorcycle wheel rim, the Nido safe car and bus bodies.

This excerpt from the ISSF Book of New Applications 2007, gives more information on applications from the automotive sector.

The following are included here:

·         Conti Support Ring

·         Exhaust system

·         Motor shaft

·         Timber truck and trailer

·         Motorcycle

Next Generation Vehicle is a research project. The conceptual vision is to provide solutions for building cars that are not only better from the environmental point of view, but better from every point of view. The project's main research field is the usability of stainless steel in automotive applications.

Paper on the occasion of the Euro Inox presentation Stainless Steel in Structural Automotive Applications – Properties and Case Studies – at the Paris Motor Show Mondial de l’Automobile, 2nd October 2000

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%.

In Stainless Steel, the passive film has the advantage, compared, for example, to a paint layer, being self-healing. Chemical or mechanical damage to the passive film will heal or repassivate in oxidising environments. Physical and mechanical properties (toughness, strength and ductility), ease of fabrication (particularly ease of forming) excellent fatigue resistance and energy absorption capability are some of the properties of Stainless Steel which enable the specific requirements of structural components to be met.

CD Rom for PC and Macintosh including:

·         Material Properties

·         Design

·         Joining

·         Service Performance

·         Finishing

·         Case Studies

This CD-ROM reflects an investigation into the use of stainless steels in the body structure of passenger cars. Specifically, it identifies the weight reduction potential in side members and cross members, which can be achieved by using this group of alloys.

To illustrate the case of novel applications, a few practicable design examples shall be discussed, which are taken from the Euro Inox CD-ROM Stainless Steel in Structural Automotive Applications? Properties and Case Studies. They were selected in view of demonstrating the combined advantages of mass saving, safety enhancement and ease of formability.

This paper discusses the influence of material selection on the improvement of the passive safety of passenger cars.

The title of this presentation contains two terms that may require further explanation: 'new' and 'light material'.