Application

Due to its exceptional qualities,stainless steel has taken a leading place among other construction materials in modern life. It is used for everything from pots and cutlery to exclusive equipment in medicine, chemical and nuclear industries. It should be noted its undoubted hygienic qualities. Stainless steel has no effect on drinking water. If chlorides or bromides up to 200 mg/l are present in water, stainless steel containing molybdenum should be used. If you compare stainless steel with copper alloys or galvanized iron, it has a higher potential in the electrochemical series. Stainless steel does not affect the taste of food, so it is the most widespread in the food industry. On the smooth high-quality surface of stainless steel, microorganisms, fungi and bacteria do not breed.

Structure features

When the remarkable properties of stainless steels are used, it is also taken into account that during technological processing they differ greatly from conventional carbon alloys. This can be explained by the peculiarities of their metastable austenitic structure, which has a number of differences. In conventional carbon ("black") steels usually achieves a stable alloy structure. When chromium is added to steel, qualities such as chemical resistance and heat resistance can be achieved. The high presence of chromium in the steel provides high oxidation resistance. If the amount of chromium is greater than 12%, a thin oxide film will form on the surface and protect the steel from corrosion.

Cr18N9 (EJ1)

This grade is considered to be the most common. It contains 0.005-0.15% C, 8-11% Ni and 18% Cr. Its tensile strength is 80 ^kg/mm2, when forged, it has an austenitic or austenitic-carbide structure, it has elongation up to 20% and impact resistance up to 10 ^kg/cm2. After quenching at 1050-1150°C with cooling in water or air, the tensile strength decreases to 60 ^kg/mm2... Despite this, elongation increases to 45-50% and impact resistance significantly increases. Quenching gives the austenitic steel a non-magnetic structure. Repeated heating of X18H9 austenitic steel to above 600°C and cold working can give partial breakdown of austenite. In addition, the steel acquires magnetic properties. Repeated heating can cause the release of chromium carbides, these make the nearby areas of the metal malochromic and therefore not very resistant to corrosion.

Intergranular corrosion

Intergranular corrosion develops when carbides are released at the grain boundaries of steel. If the steel is attacked by deep corrosion, it becomes very brittle and can break on bending, and it loses the familiar metallic sound on impact. Thus, the "knife-like" corrosion near welding seams can also be explained. If the tendency to intercrystalline corrosion is to be prevented, some titanium and niobium are added to the steel. During the formation of stronger carbides TiC, NbC, these elements bind carbon and all chromium remains in solution, thus eliminating intergranular corrosion.

Chemical resistance

A big plus is the high resistance of all stainless steel grades to organic acids, weak mineral acids and especially nitric acid. But sulfuric or hydrochloric acids can dissolve these steels. There are also very resistant grades. They include purely austenitic chromium-nickel steels that are usually rolled. These are 12X18H10T (AISI 321), 08X18H10 and 12X17 (AISI 430).

Buy, price

Evek GmbH sells high-quality stainless steel products at the best price. It is formed taking into account the technological features of production and does not include additional costs. With us you can buy in bulk a variety of products for large-scale production. We also offer good terms for retail buyers. The high level of service and delivery in the shortest possible time define the face of the company. On our site you will find all the necessary information. Our online consultant is always ready to answer your questions. Preferential discounts are available for bulk orders.