category：Building materials / date：2023-02-04 02:40:05 / browse：117 / comment：4
Since the beginning of last year, foreign countries have frequently carried out & ldquo; Double inverse & rdquo; This has a great impact on China's stainless steel casting industry. Export is a large part of the development of China's stainless steel industry and occupies a huge market share in its industrial development. In the face of economic downturn and slow development, the development of China's stainless steel industry should constantly improve product quality, Better develop overseas trade and deal with trade protectionism, combine products with environmental protection, energy resources and cultural environment, and improve the competitiveness of stainless steel products. Only in this way can we achieve an invincible position in foreign trade.Solution treatment. The main purpose of water quenching after heating the steel to ~ ℃ is to dissolve the carbide in austenite and keep this state to room temperature, so that the corrosion resistance of the steel will be greatly improved. As mentioned above, in order to prevent intergranular corrosion, solid solution treatment is usually used to dissolve CrC in austenite and then cool rapidly. Air cooling can be adopted for parts and water cooling is generally adopted.Comalapa,In order to obtain seamless pipes with smaller size and better quality, cold rolling, cold drawing or a combination of both must be used. Cold rolling is usually carried out on a two high mill. The steel pipe is rolled in an annular pass composed of variable section circular groove and fixed conical plug. Cold drawing is usually carried out on a single chain or double chain cold drawing machine of . ~ t.The back is not protected by argon, and the flux cored wire + TIG process has been applied in China for several years. Flux cored wires such as et-elt-et-elt-t-et-elt- have been produced and applied to field welding, and good economic benefits have been obtained.Shafhausen,Indicates that the chemical composition is represented by international chemical element symbols and national symbols, and the composition content is represented by letters: for example, China and Russia use fixed digit numbers to represent steel series or numbers; For example, the United States, Japan, series, series and series; The serial number is composed of Latin letters and order, which only indicates the purpose.Therefore, there are requirements for the service environment of stainless steel, and it is necessary to remove dust frequently and keep it clean and dry.Low temperature processing of stainless steel pipe --- martensite series stainless steel is quenched from austenitizing temperature and then cooled to very low temperature to promote martensite quenching. It is suitable for stainless steel easy to produce residual austenite.
Flux coated welding wire is used for backing welding, and argon gas is not used inside the weld. The welder's operation is simple and fastProduction and manufacturing can be divided into hot-rolled pipe,Comalapa2507 stainless steel strip, cold-rolled pipe, pipe,Comalapa303 stainless steel pipe,ComalapaStainless steel plate laminating machine, etc.Welding of stainless steel pipe argon arc welding stainless steel pipe: it is required to have deep penetration, no oxide inclusion, and the heat affected zone can be as small as possible. Argon arc welding maintained by tungsten inert gas has good compliance, high welding quality and good penetration function. Its commodities are widely used in chemical, which has strict requirements on the chemical composition and temperature of molten steel; In order to prevent secondary oxidation of molten steelThe continuous casting of stainless steel pipe fittings is generally matched with the refining furnace, non oxidation protection pouring is required during continuous casting production; Strict requirements for refractory materials such as ladle, nozzle and submerged nozzle.Argon shall conform to the rules of national specifications, and argon with purity of % shall be selected. If the content of impurities is too high, the maintenance effect of argon will be weakened and the weld quality will be indirectly affected.Chloride ions exist in the service environment. Chloride ions exist widely, such as salt, sweat, sea water, sea breeze, soil, floating rust of iron foam and so on. Stainless steel corrodes rapidly in the presence of chloride ions, even more than ordinary low carbon steel. Therefore, there are requirements for the service environment of stainless steel, and it is necessary to remove dust frequently and keep it clean and dry. (in this way, we can give him a & ldquo; improper use & rdquo;) there is an example in the United States: an enterprise uses an oak container to contain a solution containing chloride ions. The container has been used for nearly years. The ninetieth generation of the last century plans to replace it. Because the oak material is not modern enough, the container leaks due to corrosion days after it is replaced with stainless steel.
Martensitic stainless steels typical martensitic stainless steels include Cr ~ Cr and Cr, which have good processing properties. Deep drawing, bending crimping and welding can be carried out without preheating. Crl does not require preheating before cold deformation, but preheating is required before welding. crlcr is mainly used to make corrosion-resistant structural parts such as steam turbine blades,Typical ferritic stainless steels are Crl, Cr and Cr. after deep drawing, small black spots and RI high imitation dging will also appear on the surface of the area with large deformation, which will affect the BQ attribute.Model & mdash; Add a small amount of sulfur and phosphorus to make it easier to cut.Comalapa,Model & mdash; other properties are similar except that the risk of weld corrosion is reduced due to the addition of titanium.Application: utility boiler industry, mainly in key parts such as high temperature section of superheater and reheater.In engineering, the following methods are often used to prevent intergranular corrosion: reduce the amount of carbon in steel so that the amount of carbon in steel is lower than the saturated solubility of austenite in equilibrium, that is fundamentally solve the problem of precipitation of chromium carbide (crc) on the grain boundary. Generally, the requirement of intergranular corrosion resistance can be met when the amount of carbon in steel is reduced to less than .%.
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