202 202 stainless steel Chinese name belongs to a series of 200 series stainless steel nickel content in the chemical composition of the general 2 Introduction 3 4 4 percent in the mechanical properties of the manganese content of about 8 percent below a directory owned a series of five stainless knowledge belongs to the series 202 stainless steel 200 series stainless steel one, GB model 1Cr18Mn8Ni5N. A low-nickel 200 series stainless steel high-manganese steel, nickel content of about manganese content of 8%, is the section of nickel stainless steel. 2 Introduction 202 stainless steel is widely used in building decoration, municipal engineering, highway guardrail, hotel facilities, shopping malls, glass handrails, public facilities and other places. By precision automated system of equipment, pitting itself dissolved by welding, rolled forming, in the absence of any metal filler, the filled gas (outside of the tube) welded for TIG welding process, and for the vortex line solution testing. 3 Chemical Composition Chemical Composition /% Grade C Si Mn PS Ni Cr Mo Cu N other 202 ≤0.15 ≤1.0 ≤7.5 ~ 10.0 ≤0.060 ≤0.03 4.00 ~ 6.00 17.0 ~ 19.0 - - ≤0.25 4 grade heat treated mechanical properties of yield strength psi psi tensile modulus of elasticity psi HBS HRB HV 202 1010 ~ 1120 fast-cooling ≥2450000 ≥5900000 ≥400000 ≤207 ≤95 ≤218 5 Knowledge stainless steel (Stainless Steel) refers to the resistance of air, steam, water and other corrosive medium and weak acid, alkali, salt and other chemical etching medium corrosion of steel, also known as acid-resistant stainless steel. Practical applications, often the weak corrosion resistance as stainless steel corrosion media, while the chemical resistance of steel known as acid corrosion of steel. As the two differences in the chemical composition, the former is not necessarily resistant to chemical corrosion, while the latter generally has a stainless steel sex. The corrosion resistance of stainless steel depends on the alloying elements contained. Types of stainless steel is often divided by organizational status: martensitic steels, ferritic steels, austenitic steel. In addition, according to the ingredients into: chrome stainless steel, chrome-nickel stainless steel and chrome manganese nitrogen stainless steel. 1, ferritic stainless steel: chromium 12% to 30%. Its corrosion resistance, toughness and weldability with the increase of chromium content increased resistance to chloride stress corrosion better than other types of stainless steel. Fall into this category have Crl7, Cr17Mo2Ti, Cr25, Cr25Mo3Ti, Cr28 and so on. Ferritic stainless steel because of high chromium content, corrosion and oxidation resistance are relatively good, but poor mechanical properties and process performance, and more for large discontinuity acid structure and antioxidant for steel. Such steel is resistant to corrosive atmosphere, nitric acid and saline solution, and has good oxidation resistance, thermal expansion coefficient, etc., for the nitric acid plant equipment and food, can also be produced parts at high temperatures, such as gas turbine parts, etc. . 2, austenitic stainless steel: more than 18% chromium, it also contains about 8% nickel and a small amount of molybdenum, titanium, nitrogen and other elements. Good overall performance, corrosion resistant variety of media. Common austenitic stainless steel grades are 1Cr18Ni9,0Cr19Ni9 like. 0Cr19Ni9 steel wC <0.08%, steel marked "0." This kind of steel contains large amounts of Ni and Cr, the steel at room temperature was austenitic state. Such steel has good ductility, toughness, weldability and corrosion resistance, corrosion resistance are good in oxidizing and reducing medium, used to produce acid and equipment, such as containers and equipment corrosion lining, pipelines, corrosion equipment parts, such as nitric acid. Austenitic stainless steels commonly used solution treatment, is about steel heated to 1050 ~ 1150 ℃, and then cooled to obtain a single-phase austenite. 3, austenitic - ferritic duplex stainless steel: the advantages of both austenitic and ferritic stainless steel, and has superplasticity. Austenitic and ferritic stainless steel accounts for about half of each organization. In the case of containing a lower C, Cr content of 18% ~ 28%, Ni content of 3% to 10%. Some steel further contains Mo, Cu, Si, Nb, Ti, N and other alloying elements. Both austenitic class steel and ferritic stainless steel features, higher compared with ferrite, ductility, toughness, brittle at room temperature, resistance to intergranular corrosion and welding performance are significantly improved, while also maintaining a ferritic stainless steel 475 ℃ brittle and high thermal conductivity, with superplastic characteristics. Compared with the austenitic stainless steel, high strength and resistance to intergranular corrosion and chloride stress corrosion has significantly improved. Duplex stainless steel has excellent resistance to pitting corrosion, but also a section of nickel stainless steel. 4, martensitic stainless steel: High strength, but poor ductility and weldability. Martensitic stainless steel grades are commonly 1Cr13,3Cr13 etc., due to higher carbon, it has a high strength, hardness and wear resistance, corrosion resistance, but somewhat less, the requirements for high mechanical properties, corrosion resistance General requirements on the part of some, such as springs, turbine blades, valves and other hydraulic press. Such steel is after quenching, tempering use. Stainless steel does not produce effects corrosion, pitting, corrosion or wear. One of the highest strength of the material with metal or stainless steel construction materials. Because stainless steel has good corrosion resistance, so it can maintain a permanent structural component engineering design integrity. Chromium stainless steel is also set mechanical strength and high elongation in one, easy-to-parts manufacturing, to meet the needs of architects and structural designers. Typical uses most of the requirements is to maintain long-term building of the original appearance. In determining to choose the type of stainless steel, the main consideration is the aesthetic standards required by the system to be used to clean the corrosion and the location of the atmosphere. However, a growing number of other applications, or just looking for the integrity of the structure is not permeable. For example, industrial building roof and side walls. In these applications, the construction cost of ownership may be more important than the aesthetic, the surface is not very clean and can be. Effect of using 304 stainless steel in dry indoor environment is quite good. However, in rural and urban outdoors in order to maintain their appearance, they need regular cleaning. In heavily polluted industrial areas and coastal areas, the surface will be very dirty, and even rust. But to get the aesthetic effect of the outdoor environment, it requires the use of nickel-containing stainless steel. So, 304 stainless steel is widely used in curtain wall, side walls, roofs and other construction purposes, but in severe erosion of industrial or marine atmosphere, the best use of 316 stainless steel. Stainless steel sliding door now, it has been fully aware of the use of stainless steel in structural applications superiority. There are several design criteria are included in the 304 and 316 stainless steel. Because "duplex" 2205 has already good resistance to atmospheric corrosion and high tensile strength and elastic limit of integration, so that the European criteria also included the steel. In fact the shape of the product, stainless steel is the whole shape and size of the standard metal manufacturing, and there are many special shapes. The most commonly used products are made with sheet and strip, and plate production with special products, for example, the production of hot-rolled structural steel and structural steel extrusion. And there are round, oval, square, rectangular and hexagonal welded or seamless steel tubes and other forms of products, including profiles, rods, wire and castings. As will talk about the state of the surface, in order to meet the aesthetic requirements of architects, has developed a wide variety of commercial surface processing. For example, the surface can be highly reflective or matte; may be glossy, polished or embossed; may be colored, color, plating or etching a pattern in a stainless steel surface, can also be performed, such as drawing, in order to meet the various requirements of the designer appearance. Easier to keep the surface state, simply can occasionally be washed to remove dust. Because of good corrosion resistance, can be easily contaminated surfaces to remove graffiti or the like other surface contamination.