Stainless steel alone. Stainless steel, due to its superior corrosion resistance relative to most other metals, including steel and aluminum, becomes the cathode accelerating the corrosion of the anodic metal. An example is the corrosion of aluminum rivets fastening stainless steel sheets in contact with water. At elevated temperatures all metals react with hot gases. The most common high temperature gaseous mixture is air, and oxygen is the most reactive component of air. Carbon steel is limited to ~ in air. Chromium in stainless steel reacts with oxygen to form a chromium oxide scale which reduces oxygen diffusion into the material. The
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