Common Stainless Steel Wire Material Types and Applications

Commonly used stainless steel wire material types and applications
Steel wire that is resistant to corrosion by weak corrosive media such as air, steam, and water, and chemically corrosive media such as acids, alkalis, and salts is also called stainless acid-resistant steel wire. In practical applications, steel wire that is resistant to corrosion by weak corrosive media is often called stainless steel wire, and steel that is resistant to corrosion by chemical media is called acid-resistant steel wire. Due to the difference in chemical composition between the two, the former is not necessarily resistant to corrosion by chemical media, while the latter is generally rust-resistant. The corrosion resistance of stainless steel wire depends on the alloying elements contained in the steel wire. Chromium is the basic element that makes stainless steel wire corrosion-resistant. When the chromium content in steel reaches about 12%, chromium reacts with oxygen in the corrosive medium to form a very thin oxide film (self-passivation film) on the surface of the steel, which can prevent further corrosion of the steel wire matrix. In addition to chromium, commonly used alloying elements include nickel, molybdenum, titanium, niobium, copper, nitrogen, etc., to meet the requirements of stainless steel wire organization and performance for various uses. 0.4mm stainless steel wire.

　　Stainless steel wire is usually divided into the following types according to the matrix structure: ① Ferritic stainless steel wire, containing 12%-30% chromium. Its corrosion resistance, toughness and weldability increase with the increase of chromium content, and its resistance to chloride stress corrosion is better than other types of stainless steel wire. ② Austenitic stainless steel wire, containing more than 18% chromium, about 8% nickel and a small amount of molybdenum, titanium, nitrogen and other elements. It has good comprehensive performance and can resist corrosion from a variety of media. ③ Austenitic-ferritic duplex stainless steel wire. It has the advantages of both austenitic and ferritic stainless steel wires and has superplasticity. ④ Martensitic stainless steel wire. It has high strength, but poor plasticity and weldability. 0.2mm stainless steel wire.

　　300 Austenitic stainless steel wire
　　Model 301-Good ductility, used for molded products. It can also be hardened quickly by machining. Good weldability. Wear resistance and fatigue strength are better than 304 stainless steel wire.
　　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.
　　Model 304-General model; that is, 18/8 stainless steel. GB grade is 0Cr18Ni9.
　　Model 309-Better temperature resistance than 304.
　　Model 316-After 304, the second most widely used steel grade, mainly used in the food industry and surgical equipment, adding molybdenum to obtain a special corrosion-resistant structure. Because it has better chloride corrosion resistance than 304, it is also used as "marine steel". SS316 is usually used in nuclear fuel recovery devices. 18/10 grade stainless steel usually also meets this application level. 0.1mm stainless steel wire.
　　Model 321-Similar to 304 except that the risk of weld corrosion is reduced due to the addition of titanium.

　　400 series - ferritic and martensitic stainless steel wires
　　Model 408 - good heat resistance, weak corrosion resistance, 11% Cr, 8% Ni.
　　Model 409 - the cheapest model (British and American), usually used as automobile exhaust pipes, belongs to ferritic stainless steel (chrome steel).
　　Model 410 - martensitic (high-strength chrome steel), good wear resistance, poor corrosion resistance.
　　Model 416 - sulfur is added to improve the processing properties of the material.
　　Model 420 - "cutting tool grade" martensitic steel, similar to Brinell high chromium steel, the earliest stainless steel. It is also used for surgical knives and can be made very bright.
　　Model 430 - ferritic stainless steel, for decoration, such as for automobile accessories. Good formability, but poor temperature resistance and corrosion resistance.
　　Model 440 - high-strength cutting tool steel, with a slightly higher carbon content, can obtain a higher yield strength after proper heat treatment, and the hardness can reach 58HRC, which is among the hardest stainless steels. The most common application example is "razor blades". There are three commonly used models: 440A, 440B, 440C, and 440F (easy to process).

　　500 Series - Heat resistant chromium alloy steel.
　　600 Series - Martensitic precipitation hardening stainless steel.

　　Model 630 - The most commonly used precipitation hardening stainless steel model, also commonly called 17-4; 17% Cr, 4% Ni., 18-20 chromium.

　　304 is a versatile stainless steel that is widely used in the manufacture of equipment and parts that require good comprehensive properties (corrosion resistance and formability).

　　Type 316 stainless steel contains molybdenum, so its pitting corrosion resistance in marine and chemical industrial environments is much better than that of 304 stainless steel. Among them, type 316 stainless steel consists of variants including low-carbon stainless steel 316l, high-strength stainless steel 316n containing nitrogen, and free-cutting stainless steel 316f with a high sulfur content.

　　304 and 316 stainless steel are grades of stainless steel produced according to the American ASTM standard. 304 is equivalent to my country's 0Cr19Ni9 (0Cr18Ni9) stainless steel. 304 contains 19% chromium and 9% nickel.

　　316 is equivalent to my country's 0Cr17Ni12Mo2 stainless steel. 316 contains 17% chromium, 12% nickel and 2% molybdenum.