As a universal stainless steel, 304 is widely used to make equipment and components that require better overall performance. 304 stainless steel is produced by the United States ASTM standard stainless steel, the national standard is 0Cr19Ni9 stainless steel. 304 stainless steel chromium content is 19%, nickel content is 9%. Because the stainless steel needs to maintain inherent corrosion resistance, so the chromium content in its chemical composition must be above 12%. Now 304 is the most widely used stainless steel, heat-resistant steel, practical steel.
In the case of 304 stainless steel pipes, as stainless steel, they are widely used in food storage equipment, general chemical equipment and atomic energy industrial equipment.
In addition, 304 stainless steel pipe rust resistance is better than the 200 series stainless steel pipe, its high temperature performance is relatively good, can be as high as 1000-1200 degrees.
304 stainless steel pipe in the air or chemical corrosive medium corrosion and corrosion and intergranular corrosion resistance are very good, this kind of material at a concentration of more than 65% of boiling temperature following nitrate, with strong corrosion resistance. And the alkali solution and most organic acids and inorganic acids also have very good corrosion resistance.
The current mainstream 304 stainless steel pipe many categories, can be divided into a seamless pipe and welded pipe, can also be classified according to the structure of the basic structure, divided into 304 stainless steel and 304 stainless steel pipe for fluid transport industry, also can according to GB, JIS, the division of the 304 stainless steel standard pipe.
304 stainless steel pipe processing flow mainly has two kinds. One is hot rolling, that is, extruded seamless steel pipe, one is cold drawn (rolling) processing.
304 stainless steel pipe weight formula is [(outer diameter – wall thickness) wall thickness]0.02491=kg/ meters (per meter weight), its theoretical weight formula is (outer diameter wall thickness) * wall thickness * 0.02491= per meter weight (kg).
In addition to the 304 stainless steel pipe, in fact, a lot of 304 – line stainless steel derived from 304 as a pipe material is appropriate. Among them, there are 304L stainless steel. 304L stainless steel is a variety of 304 stainless steel with low carbon content. It is mainly used for occasions where welding is needed. A lower carbon content minimizes the amount of carbide precipitated in the heat affected zone near the weld, while the precipitation of the carbide may result in intergranular corrosion (welding erosion) in certain environments. So, 304L stainless steel pipe is also called ultra low carbon stainless steel pipe.
By comparison of chemical composition and 304 stainless steel shows that main components of 304 stainless steel and 304L stainless steel are containing 18% chromium, 8% nickel; the main difference is that 304L stainless steel is low carbon steel 304, in normal condition, corrosion resistance of 304L stainless steel and 304 stainless steel is similar, but after welding or eliminate after stress, resistance to intergranular corrosion of 304L stainless steel is more excellent ability. So, in terms of price, 304L stainless steel is higher than 304 stainless steel,
According to the standard of stainless steel hardness, 304 stainless steel is better than 304L stainless steel, this is because the carbon content directly affects the hardness of stainless steel. There is also a 304H stainless steel series, H, which means high carbon content.
The development of 304L stainless steel, the 304L stainless steel corrosion resistance, appearance, workability, strength and other properties than other materials, and through a variety of surface treatment methods of stainless steel, can also get the color and shape of rich and colorful, rich in the development of stainless steel industry.
Source: China Stainless Steel Pipe Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)