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
Martensitic stainless steel and internal clamps). Untempered martensite is low in toughness and therefore brittle. The characteristic body-centered tetragonal martensite microstructure was first observed by German microscopist Adolf Martens around 1890. In 1912, Elwood Haynes applied for a U.S. patent on a martensitic stainless steel alloy. This patent was not granted until 1919. Martensitic stainless steel can be nondestructively tested using the magnetic particle inspection method, unlike austenitic stainless steel. Also in 1912, Harry Brearley of the Brown-Firth research laboratory in Sheffield, England, while seeking a corrosion-resistant alloy for gun barrels, discovered and subsequently industrialized a martensitic stainless steel alloy. The discovery was