Adjust the ratio of austenite forming elements to ferrite forming elements in the steel to make it have austenite + ferrite dual phase structure, in which ferrite accounts for % - %. This dual phase structure is not easy to produce intergranular corrosion.Inspection: after crimping, check the crimping size with a special gauge.Mesa,The large electric clamping tool is V power supply, and the motor drives the oil cylinder to clamp. The connecting oil pipe and quick connector must not be contaminated, otherwise the dirt entering the oil circuit system will affect the normal use of the tool. Connect the main engine and hydraulic cylinder, turn on the power supply first, then tighten the pressure relief valve, wait until the pressure gauge rises to about MPa, then open the pressure relief valve, turn off the power supply, and remove the tong head after complete pressure relief.At low temperature, ferritic stainless steel pipe has low-temperature brittleness like carbon steel, but austenitic steel does not. Therefore, ferritic or martensitic stainless steel produces low-temperature brittleness, while austenitic stainless steel or nickel base alloy does not show low-temperature brittleness. Sus (Cr) and SUS (cr) of ferritic stainless steel pipe It shows that the impact value decreases sharply at low temperature. Therefore, it is necessary to pay special attention when using at low temperature. As a way to improve the impact toughness of ferritic series stainless steel, high purification process can be considered. With the help of C and N level, the embrittlement temperature is in the range of - ℃ to - ℃Switzerland,Austenitic stainless steel austenitic stainless steel is developed to overcome the lack of corrosion resistance and brittleness of martensitic stainless steel. The basic composition is crl% and Ni%, which is referred to as - steel for short. Its characteristic is that the carbon content is less than .%, and the single-phase austenite structure is obtained by the combination of Cr and Ni.;- Ferromagnetism due to m transformation shall be considered in use (such as in instrument parts).The intergranular corrosion of austenitic stainless steel can be prevented by adding Ti, Nb and other elements that can form stable carbides (tic or NBC) and avoiding the precipitation of crc on the grain boundary.

Crimping: during crimping, the convex part of the pipe fitting is placed in the concave groove of the die and the jaw is perpendicular to the pipe axis.Tax included: the invoice contains % tax, so it will also affect subsequent quotations.When using this method, it should be noted that the water-soluble paper should be double-layer and must be pasted well, otherwise it is easy to cause damage and fall off of the water-soluble paper, resulting in loss of argon protection of the inner weld and oxidation, resulting in cutting of the weld junction and re welding, which can not ensure the welding quality and seriously affect the construction period. Therefore, the water-soluble paper should be strictly checked and pasted before welding.Direct material, concrete strength a total of concrete-filled steel tubular shear members were fabricated to study the effects of outer steel pipe material, void ratio and shear span ratio on the shear capacity of concrete-filled steel tubular in pipe. It is found that the shear strength of members increases with the decrease of void ratio and the increase of concrete strength; The larger the shear span ratio, the smaller the shear strength. Combined with the test, the empirical formula of shear capacity of concrete-filled steel tubular in pipe is proposed, which is analyzed and verified by ABAQUS finite element modeling software. The results show that the simulation is in good agreement with the test results. In order to study the axial compression performance of stainless steel tube concrete conduit leg and the axial compression performance of stainless steel concrete conduit leg, experiments are used to verify the correctness of the finite element model. The load displacement curves of specimens in groups were compared, and the effects of different void ratio, concrete strength, diameter thickness ratio and bone index on the axial compression performance of concrete-filled stainless steel tubular short columns under axial compression were analyzed. The results show that with the increase of concrete strength the bearing capacity of specimens increases, but the ductility of specimens decreases; With the increase of void ratio and diameter thickness ratio, the bearing capacity of the specimen decreases; The bearing capacity of stainless steel tube concrete can be effectively improved by adding steel bone; Increasing the bone matching index of steel bone can improve the bearing capacity of the specimen. Based on the jacket offshore platform, it is proposed to replace the four hollow steel conduit legs of the original offshore platform with concrete-filled steel tube in stainless steel tube to form a new composite offshore platform with concrete-filled steel tube in stainless steel tube, so as to improve the ice resistance and disaster prevention ability of the offshore platform. The scale test on the offshore platform shows that the composite offshore platform of concrete filled steel tubular in stainless steel pipe (hereinafter referred to as the composite offshore platform) has better anti icing performance than the ordinary jacket offshore platform. Taking push as an example, the peak acceleration and displacement of the upper deck of the composite offshore platform of concrete filled steel tubular in stainless steel pipe are reduced by % and % respectively. The analysis of ABAQUS finite element and experimental simulation results shows that the error of the two results can be basically within %. Through the simulation analysis of the ultimate bearing capacity of the stainless steel tube in tube concrete-filled steel tubular composite platform and the original offshore platform, it can be seen that the stainless steel tube in tube concrete-filled steel tubular composite platform has stronger ultimate bearing capacity. Therefore, longitudinal strain and circumferential strain of the short columns under axial compression were measured. The effects of steel tube wall thickness and concrete strength on the bearing performance of the short columns were investigated. Reference was made to the European Code for design of concrete filled steel tubes (Eurocode), American code (ACI -) and Japanese code (aij-cft), China's relevant regulations D --dlt- and CECS calculate the preparation of stainless steel pipe construction,MesaStainless steel strip, prepare construction scheme and construction schedule scheme, and establish quality standards.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,MesaStainless steel water pipe, 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.The petrochemical industry, including the chemical fertilizer industry, , l, etc., with an outer diameter of about ￠ - ￠ and a wall thickness of about mm-mm (generally medium and low pressure transmission pipes with a specification of more than & phi; mm). The specific application fields are: furnace pipes, material transmission pipes, heat exchanger pipes, etc.

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,MesaStainless steel pipe manufacturer, missile and aerospace industry stainless steel pipe plays an increasingly important role in national defense industry, science and technology and economic construction.Installation materials,At present, stainless steel backing is divided into two processes: back argon filling and non argon filling. Back argon filling protection can be divided into solid wire + TIG process and solid wire + TIG + water-soluble paper process; The back non argon filling protection is also divided into flux cored wire backing welding and welding rod (flux coated wire) backing TIG welding.　　SPHCSPHC—& mdash; In the first place, s is the abbreviation of steel, P is the abbreviation of plate, h is the abbreviation of hot heat, and C is the abbreviation of commercial. It generally represents hot-rolled steel plate and strip.Body austenitic stainless steel seamless steel pipe and welded steel pipe stainless steel pipe for mechanical structure stainless steel pipe for ordinary pipe stainless steel pipe for boiler, stainless steel pipe for heat exchanger and seamless steel pipe for chemical industry (crnit) qhyad crnimosi duplex stainless steel seamless steel pipe. Stainless steel is mainly used in the automobile industry accounting for more than % of the total consumption of automobile stainless steel, and % is ferritic stainless steel. The exhaust gas produced by automobile engine is from the rear of intake pipe, front pipe, hose, converter and center pipe. The common steel grades of exhaust system are L, l, s stainless steel pipe and L stainless steel pipe are provided for a long time. The products are complete, excellent quality and favorable price. The use ratio of stainless steel pipe and welded pipe is about :.Mesa,The specific steps of continuous casting billet process of stainless steel pipe fittings are as follows: according to different steel grades, the vibration process of mold is matched with protective slag which can improve the yield of %, save energy and shorten the production cycle, so as to improve the yield of molten steel.;- Ferromagnetism due to m transformation shall be considered in use (such as in instrument parts).Hardness test: annealed stainless steel pipes with inner diameter of more than mm and wall thickness of less than mm can be tested by w-b Vickers hardness tester, which is very fast and simple, and is suitable for rapid and nondestructive qualification test of stainless steel pipes. For stainless steel pipes with inner diameter of more than mm and wall thickness of more than mm, Rockwell hardness tester shall be used to test HRC hardness. Stainless steel pipes For stainless steel pipes with inner diameter greater than mm and wall thickness less than mm, the surface Rockwell hardness tester shall be used to test HRT or hrn hardness. For stainless steel pipes with inner diameter less than mm and greater than mm, the special Rockwell hardness tester for pipes shall be used to test hrt hardness. When the inner diameter of stainless steel pipes is greater than mm, the Rockwell or surface Rockwell hardness tester can also be used to test the hardness of pipes.