Martensitic stainless steel Martensitic stainless steel Martensitic stainless steel is a specific type of stainless steel alloy. Stainless steels may be classified by their crystalline structure into three main types: "austenitic", "ferritic" and "martensitic". Martensitic stainless steels can be high- or low-carbon steels built around the Type 410 composition of iron, 12% chromium, and up to 1.2% carbon. They are hardenable by heat treatment (specifically by quenching, or by quenching and tempering). The alloy composition, and the high cooling rate of quenching enable the formation of martensite. Tempered martensite gives steel good hardness and high toughness; used largely for medical tools (scalpels, razors
Stainless steel in London in 1929. Brearley applied for a US patent during 1915 only to find that Haynes had already registered a patent. Brearley and Haynes pooled their funding and with a group of investors formed the American Stainless Steel Corporation, with headquarters in Pittsburgh, Pennsylvania. In the beginning, stainless steel was sold in the US under different brand names like "Allegheny metal" and "Nirosta steel". Even within the metallurgy industry the eventual name remained unsettled; in 1921 one trade journal was calling it "unstainable steel". In 1929, before the Great Depression hit, over 25,000 tons of stainless steel were manufactured