A, stainless steel profile
Weak corrosive medium such as air, steam, water resistant and chemical etching media such as acid, alkali, salt corrosion of the steel. Also known as stainless acid-resisting steel. In the practical application, often called the weak corrosive medium corrosion resistant steel, stainless steel, corrosion of steel and resistance to chemical media referred to as the acid resistant steel. Due to the chemical composition on the difference between the two, the former not resistant to chemical corrosion medium, while the latter are generally not rust. The corrosion resistance of stainless steel depends on the alloy elements contained in steel. Chrome is the basic element to stainless steel for corrosion resistance, when about 12% chromium content in steel, chromium and oxygen corrosion medium, in the steel surface to form a very thin layer of oxide film (since the passivation film), can prevent steel substrate further corrosion. Besides chromium, commonly used alloying elements are nickel, molybdenum, titanium, niobium, copper, nitrogen, etc, to meet the various USES of stainless steel organization and performance requirements. Stainless steel usually according to the matrix was divided into: (1) ferritic stainless steel. Chromium containing 12% ~ 30%. Its corrosion resistance, toughness and weldability with chromium increases with the increase of chloride stress corrosion resistance is superior to other types of stainless steel. (2) the austenitic stainless steel. Chromium is more than 18%, also contains 8% of nickel and trace elements such as molybdenum, titanium and nitrogen. Good comprehensive performance, corrosion resistant to a variety of media. (3) austenitic, ferritic duplex stainless steel. The advantages of both austenitic and ferritic stainless steel, and has the superplasticity. (4) martensitic stainless steel. The intensity is high, but the plasticity and poor weldability.
Second, the history of stainless steel
Stainless steel is a 60 year development course of modern material
3, stainless steel
Since the invention of stainless steel at the turn of the century, the stainless steel sent the image of modern materials and construction application of reputation, make its competitors envy. Stainless steel does not produce corrosion, pitting, corrosion or wear and tear. Stainless steel is used in one of the highest material strength of metallic materials. Due to the stainless steel has good corrosion resistance, so it can make structure parts permanently maintain the integrity of engineering design. Chromium stainless steel also has high mechanical strength and extensibility, easy parts processing and manufacturing, to meet the needs of architects and structural designers.
4, stainless steel nameplate grouping
Series 200 - chrome - nickel - manganese austenitic stainless steel
Series 300 - cr - ni austenitic stainless steel
Model 301 - good ductility, used for forming products. Also can rapid hardening by mechanical processing. Good weldability. Abrasion resistance and fatigue strength is better than 304 stainless steel.
Model 302-304, corrosion resistance due to the carbon intensity of relatively high and better.
Model 303 - by adding a small amount of sulfur and phosphorus to make it easier to 304 machining.
Model 304 - gm model; The 18/8 stainless steel. GB brand of 0 cr18ni9.
Model 309 a better temperature resistance than in 304