Stainless steels are most notable for their corrosion resistance, which increases with increasing chromium content. Additions of molybdenum increase corrosion resistance in reducing acids and against pitting attack in chloride solutions. Thus, there are numerous grades of stainless steel with varying chromium and molybdenum contents to suit the environment the alloy must endure. Stainless steels resistance to corrosion and staining, low maintenance, and familiar luster make it an ideal material for many applications where both the strength of steel and corrosion resistance are required.
Stainless steel is an alloy of Iron with a minimum of 10.5% Chromium. Chromium produces a thin layer of oxide on the surface of the steel known as the 'passive layer'. This prevents any further corrosion of the surface. Increasing the amount of Chromium gives an increased resistance to corrosion. Stainless steel also contains varying amounts of Carbon, Silicon and Manganese. Other elements such as Nickel and Molybdenum may be added to impart other useful properties such as enhanced formability and increased corrosion resistance.
Stainless steel is a generic term for a family of corrosion resistant alloy steels containing 10.5% or more chromium. All stainless steels have a high resistance to corrosion. This resistance to attack is due to the naturally occurring chromium-rich oxide film formed on the surface of the steel. Although extremely thin, this invisible, inert film is tightly adherent to the metal and extremely protective in a wide range of corrosive media. The film is rapidly self repairing in the presence of oxygen, and damage by abrasion, cutting or machining is quickly repaired.
The global stainless steel market size is expected to reach USD 133.8 billion by 2025 at a 5.2% CAGR, according to a new report by Grand View Research, Inc. The market is anticipated to expand mainly due to advantages such as increased formability, weldability, corrosion resistance, and aesthetic appearance.
The market for stainless steel is forecasted to increase by 3 percent until 2020. The increase in urbanization and modernization globally are the main reasons for this growth. Moreover, the growth in the automotive industry along with the growing demand for energy and water will likely maintain the demand for stainless steel in near future. The key driver of the stainless steel industry is the increasing demand from downstream industries such as agriculture, processing industry, consumer products, and construction industry.