The material of stainless steel

Introduction to Stainless Steel Materials

Stainless steel is a kind of high-alloy steel that can resist corrosion in air or chemically corrosive medium. Stainless steel has beautiful surface and good corrosion resistance. It does not need to undergo surface treatment such as color plating, and the inherent surface performance of stainless steel is 12%. Chromium above. Therefore, many machinery factories often do not do any paint treatment in order to show that they are stainless steel, and the black material (the so-called black material is the name of general steel) must be treated with anti-rust.

Stainless steel material composition

The corrosion resistance of stainless steel depends on the alloying elements contained in the steel. Chromium is the basic element for stainless steel to obtain corrosion resistance. When the content of chromium in steel reaches about 12%, the action of chromium and oxygen in corrosive medium forms a thin oxide film on the surface of steel, which can prevent the matrix of steel. further corrosion. In addition to chromium, the commonly used alloying elements are nickel, molybdenum, titanium, niobium, copper, nitrogen, etc., to meet the requirements of various uses for the structure and properties of stainless steel.

Models in stainless steel

301—Good ductility, used for molded products. It can also be hardened by mechanical processing. Good weldability. Wear resistance and fatigue strength are better than 304 stainless steel. Model 302—corrosion resistance is the same as 304, but the strength is better due to the relatively high carbon content. Model 303 - It is easier to cut than 304 by adding a small amount of sulfur and phosphorus. Type 316 - the second most widely used steel after 304, mainly used in the food industry and surgical equipment, adding molybdenum to obtain a special structure that is resistant to corrosion. Compared with 304, it has better resistance to chloride corrosion, so it is also used as a community letter box.

Types of stainless steel materials

The types of stainless steel materials include martensitic stainless steel, austenitic stainless steel, ferritic stainless steel, austenitic-ferritic duplex stainless steel, etc.
1. Martensitic stainless steel: high strength, but poor plasticity and weldability.
2. Austenitic-ferritic duplex stainless steel: It has the advantages of both austenitic and ferritic stainless steel, and has superplasticity.