Stainless steel as the common ferritic and austenitic stainless steels due to their low chromium content. Duplex stainless steels have a mixed microstructure of austenite and ferrite, the aim usually being to produce a 50/50 mix, although in commercial alloys the ratio may be 40/60. They are characterized by high chromium (19–32%) and molybdenum (up to 5%) and lower nickel contents than austenitic stainless steels. Duplex stainless steels have roughly twice the strength compared to austenitic stainless steels. Their mixed microstructure provides improved resistance to chloride stress corrosion cracking in comparison to austenitic stainless steels Types 304 and 316. The properties of
Stainless steel grades typically EN1.4913 or 1.4923 are used in parts of turbochargers, other heat resisting grades for EGR (Exhaust gas recirculation) and for inlet and exhaust valves. In addition, common rail injection systems and particularly the injectors rely on stainless steels. Stainless steel has proved to be the best choice for miscellaneous applications, such as stiffeners for windshiel wiper blades, balls for seat belt operation device in case of accident, springs, fasteners, etc. The aft body panel of the Porsche Cayman model (2-door coupe hatchback) is made of stainless steel. It was discovered during early body prototyping that conventional steel could