Lieto0Cr17Ni4Cu4Nb stainless steel plateChanges in market structure

Stainless steel pipe factory stainless steel products are widely used in hardware products, furniture, mechanical structure, mechanical accessories, precision medical instruments, fluid transmission pipelines, such as furniture, machinery, medical oil, natural gas, water, gas, steam and other industries.According to the purpose, it can be divided into oil well pipe (casing, oil pipe and drill pipe), pipeline pipe, boiler pipe, mechanical structure pipe, hydraulic prop pipe, gas cylinder pipe geological pipe, petroleum cracking pipe) and marine pipe.Lieto chemical pipe (high-pressure chemical fertilizer pipe,Improper use and maintenance will cause & ldquo; on the surface of stainless steel pipe; Floating rust& ldquo; Mildew & rdquo; And other undesirable phenomena.There shall be a special storage rack. The storage rack shall be a wooden or painted carbon steel support or padded with rubber pad to isolate it from carbon steel and other metal materials. During storage, the storage position shall be convenient for lifting and absolutely isolated from other data storage areas. Protective measures shall be taken to avoid purification, collision with other components,Flux coated welding wire (self shielded welding wire) shall be used for backing TIG welding.With the implementation of China's reform and opening up, the national economy has achieved rapid growth, and a large number of urban houses, public buildings and tourism facilities have been built, which puts forward new requirements for hot water supply and domestic water supply. In particular, people pay more and more attention to the problem of water quality, and the requirements are also increasing. Galvanized steel pipe, a common pipe, will gradually withdraw from the historical stage under the influence of relevant countries because of its corrosivity. Plastic pipe, composite pipe and copper pipe have become common pipes in the pipeline system. However, under certain circumstances, stainless steel pipe has more advantages, especially the stainless steel pipe with wall thickness of only . ~ mm. In high-quality drinking water system, hot water system and water supply system that puts safety and sanitation first, it has the characteristics of safety, reliability, sanitation, environmental protection, economy and applicability. It has been proved by engineering practice at home and abroad that it is one of the new, Sb the content of impurities such as P, Bi and as should be reduced as much as possible. In addition, A-F dual phase steel can be selected, which does not correspond to stress corrosion in Cl - and oh - media. The initial micro crack will not continue to expand after encountering ferrite phase, and the ferrite content should be about % .

Model & mdash; Martensite (high strength chromium steel), good wear resistance and poor corrosion resistance.According to rolling, it is divided into hot rolled hot drawn and cold drawn (rolled) stainless steel pipes.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 .%.Promotion, 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.Stress relief treatment. Stress relief treatment is a heat treatment process to eliminate the residual stress of steel after cold working or welding. It is generally heated to ~ ℃ for tempering. For steels without stabilizing elements Ti and Nb, the heating temperature shall not exceed ℃, so as to avoid intergranular corrosion caused by chromium carbide precipitation. For cold worked and welded parts of ultra-low carbon and stainless steel containing Ti and Nb, they need to be heated at ~ ℃ and then cooled slowly to eliminate stress (the upper limit temperature is taken for eliminating welding stress), which can reduce the tendency of intergranular corrosion and improve the stress corrosion resistance of steel.Stainless steel grade group Series & mdash; Chromium nickel manganese austenitic stainless steel series & mdash; Chromium nickel austenitic stainless steel model & mdash; Good ductility,Lieto304 stainless steel square tube, used for molding products. It can also be machined to harden rapidly. Good weldability. The wear resistance and fatigue strength are better than those of stainless steel.

Refining and transportation industries are in great demand. Secondly, geological drilling, chemical industry, construction industry, machinery industry, aircraft and automobile manufacturing, boiler, medical equipment, furniture and bicycle manufacturing also need a large number of various steel pipes. With the development of new technologies such as atomic energy, rocket, missile and aerospace industry, stainless steel pipe plays an increasingly important role in national defense industry, science and technology and economic construction.Quality inspection report,Standard classification - classification: national standard GB industry standard Yb local standard enterprise standard qcb- classification: product standard packaging standard basic standard - standard level (divided into three levels): y level: international advanced level I level: international general level H level: domestic advanced level - national standard: stainless steel bar (level I) gb- stainless welding disc Park (level H)D cold rolled, heat treated, pickled or similar matt surface.Water preparation, transportation, purification, regeneration, seawater desalination and other water industry excellent materials. The demand is about tons.Lieto, stainless steel pipe and ferritic stainless steel according to the matrix structure. Chromium content % ~ %. Its corrosion resistance, toughness and weldability increase with the increase of chromium content, and its chloride stress corrosion resistance is better than other kinds of stainless steel.Model & mdash; Commonly used precipitation hardening stainless steel model, usually also called -; %Cr%Ni.Welding, high frequency preheating plus three torch argon arc welding, high frequency preheating plus plasma argon arc welding. The progress of combined welding is very significant. As for the combined welding of steel pipe with high-frequency preheating, the weld quality is equivalent to the conventional argon arc welding and plasma welding, the welding operation is complex, and the whole welding is easy to complete automation. This combination is easy to connect with the existing high-frequency welding equipment, with low investment cost and good benefit.