Stainless steel for buses and coaches
Framing the future with stainless steel
Outokumpu stainless steels help designers to create buses and coaches with reduced weight, less maintenance, longer lifetime, improved CO2 footprint and increased safety for passengers. From frame structures and sidewalls to battery housings and electric engines for state-of-the-art electric buses, our stainless steels have the features to enable all this. We offer a variety of grades in plate and sheet, coil, strip and precision strip. Our stainless steels for bus manufacturing include the latest purpose-designed fully austenitic ultra-high strength stainless steels, as well as lean duplex and ferritic grades to meet the specific needs of our customers.
Seven reasons to put stainless steel in the frame for buses
The bus frame provides the structural backbone of a bus. This is where high strength stainless steels offer exciting possibilities to create safer and lighter buses while remaining cost competitive. This article describes how stainless steels help designers of next generation buses solve the key challenges regarding light weight, passenger safety, sustainability and cost. The article includes the latest third-party simulation test results, which show a potential of over 1,000 kg weight reduction in a bus frame when using ultra-high strength stainless steel.
Why choose stainless steel?
It's strong and lightweight
High-strength stainless steel grades developed by Outokumpu provide outstanding yield strength and energy absorption characteristics. This helps design lighter and smaller structures that still meet rigorous safety standards.
High strength of stainless steels make it possible to reduce the weight e.g. in tubular frame bus structures. Test programs have shown, that by replacing S355 grade carbon steel with duplex and ferritic stainless steels in a standard coach body, it is possible to reduce the all-up weight by around 500 kg. Outokumpu's fully austenitic nickel-free Forta H-Series offers even greater weight-saving potential with over 1,000 kg. For more information and details, please download the article "Seven reasons to put stainless steel in the frame for buses".
There is a perception that stainless steel is an expensive material to use in comparison with traditional carbon steel. That is why it is currently used in only a small percentage of buses. The reality is that making the switch to stainless steel allows designers to create safer and lighter buses while staying cost-competitive and there is very significant potential for it to be used much more widely.
When selecting a material for a bus structure, it is important to go beyond its initial purchase cost and to consider the wider implications on the total cost throughout the life of the bus. A switch to stainless steel could reduce the total life-cycle cost of a bus frame by 12% according to an analysis by International Stainless Steel Forum, see Figure 1.
Figure. 1. A switch to stainless steel could reduce the total LCC of a bus frame by 12% (ISSF, webinar 2021).
Stainless steel is the ultimate sustainable material. It is produced using a high level of scrap. As one example, Outokumpu uses over 85% scrap; the highest proportion of recycled content on the market. And at the end of its life, stainless steel is 100% recyclable.
The high durability and corrosion resistance of stainless steel means it has a much longer lifetime than carbon steel and requires much less maintenance. Furthermore, using high-strength stainless steel can reduce the overall weight of the vehicle, helping to lower energy consumption and emission levels.