and there is a large demand for building water supply pipes. According to the 'Ninth Five Year Plan' of construction and the outline of long-term objectives in

The domestic prospect is promising, the demand for each pipe is ~ km from to , including km of cold and hot water pipes in residential construction areas. Some people believe that the development of stainless steel water pipes is of great significance to improve the grade of modern urban buildings.The main control load of the platform has high requirements for the shear bearing capacity of the guide leg of the offshore platform. In order to study the factors affecting the shear capacity of the jacket legs of the stainless steel pipe in pipe concrete-filled steel tubular offshore platform, a total of concrete-filled steel tubular shear members were fabricated to study the effects of outer steel pipe material, concrete strength, 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, the composite offshore platform of concrete-filled steel tube in stainless steel tube is a good new type of jacket offshore platform. Axial compression tests were carried out on austenitic and duplex stainless steel tube concrete short columns. The ultimate load, 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), prepare construction scheme and construction schedule scheme, and establish quality standards.Wevelgem,The agitation is more direct. If there is an abnormal change in inventory, whether it increases or decreases, it will become a speculative type of mall participants.Ferritic and martensitic stainless steels are represented by series numbers. Ferritic stainless steel is marked with and , martensitic stainless steel is marked with and C, dual phase (austenite ferrite).Esquipras, such as salt sweat stains, seawater, sea breeze, soil, etc. stainless steel corrodes rapidly in the presence of chloride ions, even surpassing ordinary low-carbon steel. Chloride ions form complexes with Fe in alloy elements, reducing the positive potential of Fe, 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; High strength cutting tool steel, with slightly higher carbon content, can obtain higher yield strength after appropriate heat treatment, and the hardness can reach hrc. It belongs to hard stainless steel. A common application example is & ldquo; Shaving blade & rdquo;. There are three common models: C and f (easy to process).Surface treatment difference: surface treatment is usually divided into polishing,WevelgemHot rolled stainless steel strip, wire drawing and wire drawing, and the cost is about yuan and meter. If it is thrown into the lens barrel, the cost per ton will increase by yuan.Stainless steel has two classifications: one is divided into chromium stainless steel and chromium nickel stainless steel according to the characteristics of alloy elements; The other is divided into m stainless steel, f stainless steel, a stainless steel and A-F duplex stainless steel according to the microstructure of steel in normalized state.Range,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 fastThe main control load of the platform has high requirements for the shear bearing capacity of the guide leg of the offshore platform. In order to study the factors affecting the shear capacity of the jacket legs of the stainless steel pipe in pipe concrete-filled steel tubular offshore platform, a total of concrete-filled steel tubular shear members were fabricated to study the effects of outer steel pipe material, concrete strength, 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,Wevelgem304 manufacturer's stainless steel pipe, 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, the composite offshore platform of concrete-filled steel tube in stainless steel tube is a good new type of jacket offshore platform. Axial compression tests were carried out on austenitic and duplex stainless steel tube concrete short columns. The ultimate load, 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, prepare construction scheme and construction schedule scheme, and establish quality standards.Stainless steel precipitation hardening stainless steel and high alloy with iron content less than % are usually named by patent name or trademark.

The best way to improve the quality of stainless steel pipe fittings is to change the process from ingot to billet. Due to the improvement of continuous casting process, this has become a necessary means to improve product quality.Quality recommendation,The welding of stainless steel pipe is usually composed of backing welding, filling welding and cover welding. Backing welding of stainless steel pipe is a key link in stainless steel pipe welding, which is not only related to the quality of engineeringThe steady creep rate is usually used to evaluate the long-time creep performance of materials. For the application of long-life materials, the steady-state creep rate of stainless steel pipe under high temperature and stress is the key index of the material, and can be extrapolated. The following are the test results of stainless steel pipe under different test conditions. The results show that the steady-state creep rate of stainless steel pipe sample is in the order of magnitude after creep at ℃ (mpa ℃ (mpa) for h; when the temperature condition increases to ℃ (the stress decreases to MPa), the creep performance of stainless steel pipe sample is good, and the steady-state creep rate is in the order of magnitude; when the temperature further increases to ℃ (the temperature creep rate of mpa stainless steel pipe sample increased to ℃ (mpa steady-state creep rate reaches the maximum value under several test conditions, and creep fracture occurs. See for the change of steady-state creep rate of stainless steel pipe sample under several conditions. When the temperature increases, the material maintains a low level of creep rate. Under ℃ MPa, s creep deformation rate does not increase, which shows little influence on the temperature and stress, and creep fracture occurs under this condition Compared with several other common structural materials, it can be seen that the creep performance of several materials is better than that of ordinary materials under all test conditions. After hours of test, the total strain does not exceed .%. The curve is relatively stable and the fluctuation is small, indicating that the test data is stable and reliable. Stainless steel pipes are widely used because of their excellent corrosion resistance It is widely used in petrochemical industry, pipeline transportation and other working conditions with strong corrosive media. The main reason for the corrosion resistance of stainless steel pipes is the addition of a large number of elements CrNi, and Cr is the main element determining the corrosion resistance of stainless steel pipes. The electrode potential of stainless steel pipes jumps with the increase of Cr content. However, stainless steel pipes are in the subsequent heat treatment During the treatment, Cr element will precipitate into the matrix in the form of carbide. On the one hand, the hardness of Cr carbide is larger than that of the matrix, and the service wear process can improve the wear resistance of stainless steel pipe. On the other hand,WevelgemStainless steel connecting pipe, the precipitation of Cr containing carbide will lead to Cr Element dilution zone in some parts of the matrix, increase the number of batteries of the material reduce the electrode potential of stainless steel pipe and reverse the corrosion Therefore, in order to obtain good corrosion and wear resistance, the combination of mechanical properties and corrosion resistance of stainless steel pipe materials needs to be considered. At present, some scholars have studied the effects of austenitizing temperature and time tempering temperature and time on the mechanical properties of stainless steel pipe by heat treatment to change the corrosion resistance of stainless steel pipe And corrosion resistance, it is found that austenitizing temperature can change mechanical properties, but has little effect on corrosion performance, while tempering temperature has a great effect on the corrosion resistance of materials. Appropriate austenitizing temperature and tempering temperature can improve the corrosion and wear resistance of materials. Some scholars use surface treatment to improve the corrosion and wear resistance of materials, It is concluded that low-temperature nitriding forms a diffusion layer on the surface of the material, improves the wear resistance of the material, so that the corrosion resistance of the steel will be greatly improved. As mentioned above, 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.Wevelgem,In the interior decoration project, the proportion of water pipes is very small, whether it is data consumption or price. However, once the water pipes show achievements, the results will be very serious. Therefore, it is extremely important to choose water pipes with reliable quality, convenient maintenance, health and environmental protection. With the development of the national economy and the progress of people's living standards, people's requirements for domestic water pay more and more attention to health and environmental protection. A good water source escort pipeline has become a careful choice. Water pipes are generally experienced in lead pipes & rarr; Copper pipe & rarr; Iron pipe & rarr; Galvanized iron pipe → Plastic pipe & rarr; Development process of stainless steel pipe. It has become a trend in the world to select high-quality stainless steel materials as water supply pipes. The material indicates that in Germany, more than % of residents choose stainless steel water pipes; In Japan, more than % of households in Tokyo have adopted stainless steel water pipes; In Australia, it has begun to change other pipes to stainless steel pipes; In the United States, the water pipes of five-star hotels in Las Vegas are all made of stainless steel. Since the beginning of the st century, due to the progress of living standards, more than % of residents in China need water pipes to meet their needs of high-quality life. Therefore, sanitation, environmental protection, and has become the current world trend and development direction. Stainless steel water pipe is called the real green pipe in the st century. With the gradual standardization of stainless steel pipe industry, it can be predicted that the consumption technology and connection technology of stainless steel pipe will also slow down to standardization and become more and more perfect. The development of stainless steel pipe technology will not only create a favorable condition for health, environmental protection and sanitation for national domestic water, but also win a larger market for stainless steel pipe enterprises. Stainless steel pipe entering the construction and decoration market is an attack in the water pipe industry.When using this process, the following key points should be paid attention to: during the welding process, the correct included angle between the welding handle, welding wire and weldment should be maintained. The ideal caster angle of the welding handle nozzle is & deg; & mdash; & deg;, and the included angle between the welding wire and the weldment surface is & deg; & mdash; & deg;; correct the molten pool temperature, change the included angle between the welding handle and weldment, change the welding speed, etc. to change the molten pool temperature, so as to ensure Beautiful weld formation (uniform width no concave, convex and other defects) During operation, the current shall be slightly larger than that of solid core welding wire, and the welding handle shall be slightly adjusted to accelerate the separation of molten iron and molten flux coating, so as to facilitate the observation of molten pool and penetration; when filling the welding wire, it shall be sent to places of molten pool and pressed inward slightly to ensure penetration and prevent concave; during welding, the welding wire shall be regularly sent and taken out, and the welding wire shall always be ensured Under the protection of argon to prevent the end of the welding wire from being oxidized and affect the welding quality; pay attention to the welding quality of the arc and arc stop, and the spot weld shall be polished to & deg; the slope shall be gentle, and pay attention to the defects such as arc pit and shrinkage hole during arc stop.. It is our responsibility not to pay attention to the maintenance of the pipe during transportation, mix the pipe with corroded chemical commodities, or soak the two water into the packaging film during transportation in rainy days, which will cause rust. . It is the responsibility of the processor and manufacturer. When cutting stainless steel or iron when manufacturing goods, the scrap iron will cause rust on the surface of the steel pipe. Therefore, it is only reasonable for highly skilled technicians to deepen investigation and discussion, and who should be responsible for whose achievements. You can't let steel mills, pipe factories, processors, or users bear the liability for compensation!