The chromium in stainless steel reacts with oxygen in the air to produce a protective chromium oxide layer across the surface. Also, environments with salty water can accelerate corrosion on stainless steel.įinally, maintenance will have an effect on the metals ability to resist rust. Environments with chlorine like swimming pools are highly corrosive. The environment where the metal is used is another factor that can amplify the chances of stainless steel rusting. The elements in the different grades of stainless steel can have adverse effects on corrosion resistance. The composition of the steel is the single biggest concern when it comes to corrosion resistance. Various factors can affect the ability of stainless steel to resist corrosion. Factors Affecting Rust on Stainless Steel The higher the chromium content, the less likely the metal will rust.īut, over time and if not maintained correctly, rust can and will develop on stainless steel. Some types of stainless steel are more prone to corrosion than others, depending on the chromium content. At the moment, there are over 150 varieties of stainless steel in the market.īecause of its low maintenance nature, resistance to oxidation and staining, stainless steel is preferred in many applications, particularly those where aesthetics matter.Įven with these impressive features, stainless steel can and does rust after all, it’s 'stainless' not 'stainfree'. The chromium reacts with the oxygen in the air and forms a protective layer that makes stainless steel highly resistant to corrosion and rust. U.S.Stainless steel is a steel alloy that contains a minimum chromium content of 10.5%.OSHA requirements for protecting workers from hexavalent chromium exposure are found in specific OSHA standards covering general industry ( Chromium (VI) - 1910.1026), shipyards ( Chromium (VI) - 1915.1026), and construction ( Chromium (VI) - 1926.1126). The most toxic form of chromium is hexavalent chromium. OSHA sets enforceable permissible exposure limits (PELs) to protect workers from the health effects of exposure to chromium metal and various chromium compounds under 1910.1000 Table Z-1 Limits for Air Contaminants. Workers involved in welding, cutting, brazing, soldering, torch and other hot work operations.Workers involved in the maintenance and servicing of copying machines and the disposal of some toner powders from copying machines.Occupations that may involve chromium exposures include: Occupational exposure to chromium can occur in the following industries and operations:
Occupational exposures to chromium occur primarily in the metal and chemical manufacturing industries, although exposures are also possible in other industries where chromium compounds are used. Who is exposed to the common forms of chromium? OSHA's hexavalent chromium safety and health topics page provides comprehensive information on health effects, exposure controls, OSHA standards, and additional resources on this toxic substance. Chromium VI (hexavalent chromium) is the oxidized state of principal concern in occupational safety and health and the environment because of its extreme toxicity and designation as a human carcinogen. Chromium III is an essential trace element in humans but chronic exposure may be harmful. The oxidized states of chromium III and chromium VI are the most important forms of the chemical. Elemental chromium is seldom found naturally in the environment. In addition, chromium is used in the pigment and dye, tanning, and glassmaking industries, in reflective paints, for wood preservation, to anodize aluminum, to produce synthetic rubies, as a catalyst in chemical manufacturing and as an isotope in medicine. It is most often used as an alloy (ferrochrome) in stainless steel and in chrome plating. Chromium is valued for its high corrosion resistance and hardness. imported 430,000 metric tons of chromium, primarily from South Africa, Kazakhstan, Russia and China. production of chromium was estimated at 160,000 metric tons, coming almost entirely from recycling stainless steel scraps. Chromium is a steel gray, lustrous, hard metal extracted from chromite ores.
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