Stainless steel is an alloy of iron which contains more than 10% chromium. Stainless steel cannot be stained but occasionally dulls or will show oily finger prints. This steel is noted for its hardness and is used for utensils, tableware, sinks, counter tops, and small appliances. In the process of making it, a little of the chromium in the alloy is used to form the hard oxide coating on the surface. If this is taken off, through corrosion or wear, the steel rusts like regular steel.

Weldability
Usage of different welding performance requirements are also different. A general class of cutlery on the welding performance is not required, even including some pot enterprises. But most products require materials welding performance is good, like second-class cutlery, mug, steel, water heaters, drinking fountains, etc.

Corrosion Resistance
The vast majority of stainless steel products require good corrosion resistance , like a second class tableware, kitchen utensils, water heaters, drinking fountains, and some foreign businessmen corrosion products also do test: NACL solution heated to boiling, pour some time after solution off , washed dried and weigh loss , to determine the degree of corrosion ( NOTE: the product is polished by sandpaper or emery cloth containing Fe component, the surface can cause rust test ).

Polished Performance
Today’s society is generally in the production of stainless steel products are polished in this process, only a few products such as water heaters, drinking fountains, etc. does not require polishing liner. Therefore, the performance of which requires a good polishing materials. The main factors affecting the polishing performance are the following:
① raw surface defects. Such as scratches, pitting, excessive pickling.
② raw material problem. Hardness is too low, it is not easy to throw light (BQ is bad ) when polished , and the hardness is too low, in the deep stretch prone to orange peel surface, thus affecting BQ sex. BQ relatively high hardness like.
③ After deep drawing of products, the deformation of the surface area will be a great little black dots and RIDGING, thus affecting BQ sex.

Heat Resistance
Refers to a high temperature heat resistance of stainless steel can maintain its excellent mechanical properties.
The impact of carbon: carbon in austenitic stainless steel is a strong and stable. Austenite and expanded set of elements austenite. The ability of carbon to austenite is about 30 times of nickel, carbon, is an interstitial element, solid solution strengthening can significantly improve the strength of austenitic stainless steel. Carbon can also improve the performance of austenitic stainless steel in a high concentration of chloride (e.g., boiling 42% MgCl2 solution) resistance to stress corrosion.
However, in austenitic stainless steel tube, carbon is often seen as harmful elements, mainly due to the corrosion of the stainless steel under some conditions of use ( such as by welding or heating 450 ~ 850 ℃ ), with carbon steel Cr23C6 type carbon chromium compounds leading to the formation of high chromium chromium partially depleted , especially the corrosion resistance of the steel is decreased resistance to intergranular corrosion. Therefore. Chrome-nickel austenitic stainless steel is mostly carbon content of new developments since the 1960s, less than 0.03 %, or 0.02% of ultra-low carbon type, known as the carbon content can be reduced susceptibility to intergranular corrosion of steel decreases when the carbon content of less than 0.02% that has the most significant effect, some experimental pearl also noted that carbon will increase the tendency of pitting corrosion of austenitic stainless steel chrome. Due to the harmful effects of carbon, not only in austenitic stainless steel smelting requires control over and shall be as low carbon content , but also in the subsequent heat, cold and heat treatment process also prevents the surface of carbon steel and chromium free carbide precipitation.

Corrosion Resistance
When the number of atoms of chromium content in the steel is not less than 12.5%, the electrode potential of steel can be mutated, by the negative potential of the positive electrode potential rises. Prevent galvanic corrosion.

Applications

Stainless steels find use in a very wide variety of applications. Some typical examples are:
 
Consumer goods: Applications here include domestic kitchenware and tableware, kitchen sinks, laundry equipment and electrical and electronic appliances.
 
Architecture, building & construction: Stainless steel has been used in numerous famous buildings. The Chrysler Building in New York, the world’s tallest building when it was built in 1929, used Type 302 (similar to Type 304) for the roof and upper structure. Type 316 is used to clad the outside of Petronas Twin Towers in Kuala Lumpur, currently the world’s tallest buildings, and Jin Mao Tower in Shanghai, the third tallest. More common applications are balustrades, column wraps, roofing and guttering, signage, curtain wall supports, light poles, elevator doors and public seating. Stainless steel rebar is used in bridges, barrier walls and decking to extend the life of critical areas of roadways and marine structures.
 
Food and beverage industry: Type 304 and, in more aggressive situations, Type 316 are widely used in this industry for food and beverage production (milk silos, cheese vats, beer and wine fermenters, fruit juice tanks and piping), storage (wine tanks, beer kegs), cooking (large commercial kitchens) and serving (display cabinets, bench tops). Stainless steel equipment is easy to clean (sanitize) and also preserves the purity of the food.
 
Transportation: A wide range of both decorative and functional components are fabricated from stainless steel, such as automotive exhaust systems, fasteners, trim, wheel covers and windscreen wiper arms; passenger railcars, coal wagons, bus frames and milk tankers; and seagoing chemical tankers.
 
Chemical, petrochemical, oil and gas, pulp and paper industries, and power generation: This field represents a very diversified market for stainless steel with many specialised applications such as heat exchangers, vessels for various types of chemicals, pipe, fittings, valves, pumps, mixers, high temperature furnace equipment, components for nuclear reactors, and gas and water turbines.