Good ductility, it is not easy to polish (BQ is not good). If the hardness is too low, orange peel is easy to appear on the surface during deep drawing, which affects BQ performance. BQ with high hardness is relatively good.Santiago-de-las-Vegas,Han Jianbiao, an analyst at Zoomlion steel, pointed out that since, China's steel pipe exports have been only or tons per month of which seamless pipe exports are only about tons per month.Application field: tubular boiler for pipeline in harsh seabed environment product description: ultra (ultra) critical unit is the basis of modernization of power generation equipment and energy conservation and emission reduction. Among the important pressure parts of ultra (supercritical) boiler, superheater and reheater are the parts with high working temperature and bad working environment. Previously,Santiago-de-las-VegasAnnular stainless steel belt, all such materials used in China were imported from abroad, while only steel material manufacturers in the world have limited capacity. Such materials have a large gap, expensive import prices, difficult procurement and short supply, which seriously affected the production of ultra supercritical boilers and the development of electric energy in China. At present, China's demand for utility boiler tubes is about tons, and with the continuous improvement of ultra (supercritical) power generation technology, the demand is expanding. Several large domestic enterprises have invested a lot of human and financial resources in the R & D and production of such products, and have made considerable achievements. On the one hand, but also brought considerable economic benefits to enterprises.Ponte do Lima,Corrosion resistance of decorative stainless steel pipe the price of different series of stainless steel materials varies greatly. The corrosion resistance of more economical materials can not meet the higher application requirements, and the improvement of corrosion resistance of stainless steel materials by simple chemical passivation is limited. On the other hand, the traditional passivation treatment containing chromium salt has been gradually eliminated, and the passivation treatment of stainless steel has turned to the direction of environmental friendliness. Recently, citric acid passivation and silicon treatment on stainless steel surface have become a new research direction. The former has environmental protection characteristics because its passivation solution component does not contain chromium salt. The latter has found that silicon coupling agent is chemically adsorbed on the metal surface to form a protective silicon film with cross-linked network structure. The length of discoloration time of samples after different surface treatments was compared by blue dot method, the corrosion rate of samples after different surface treatments was distinguished by brine immersion test, and the salt spray resistance of samples after different surface treatments was distinguished by neutral salt spray test, The differences of pitting corrosion resistance and resistance to corrosive medium of samples after different surface treatment were compared by electrochemical test. The film thickness of silicon film was indirectly characterized by film weight test, and scanning electron microscope, energy spectrometer, X-ray diffraction X-ray photoelectron spectroscopy and total reflection Fourier transform infrared spectroscopy characterized the surface films of different surface treated samples, and analyzed the structural composition and corrosion resistance mechanism of different films. Professional stainless steel plate, stainless steel coil, stainless steel belt, high price, service, on-site settlement, honest management! At present, there are few studies on the combination of citric acid passivation and silicon treatment of stainless steel. Therefore, this paper studies the difference of corrosion resistance of martensitic stainless steel Cr chemical passivation, silicon treatment and the combination of citric acid passivation and acid silicon system treatment, and discusses the corrosion resistance mechanism of different films on its surface, which can provide reference for the new direction of stainless steel surface treatment, It has certain practical guiding significance. The corrosion resistance and mechanism of chemical passivation, silicon treatment and composite treatment of martensitic stainless steel were studied in this paper. The comprehensive comparison of the research results shows that the corrosion resistance of stainless steel treated with different surface treatments is different. The corrosion resistance of the sample treated with silicon alone is better than that treated with traditional dichromate passivation. The corrosion resistance of the composite treated sample treated with citric acid passivation and acid silicon system is further enhanced than that treated with acid silicon system alone. The composite treatment of citric acid passivation and acid silicon system treatment has excellent corrosion resistance and environmental protection characteristics, and is expected to replace the traditional dichromate passivation treatment. According to the film weight test results, the surface silicon film weight of the composite treated sample after citric acid passivation and acid silicon system treatment is lower than that of the sample after acid silicon system treatment alone, indicating that the excellent corrosion resistance of the composite film not only depends on the surface silicon film, but also benefits from its double-layer film structure.After fine tuning the molten steel temperature in the argon blowing station, it is lifted to the ladle rotary table for continuous casting.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 engineering

The bright nickel layer on the stainless steel pipe is a silver white metal with slight yellow light. Its hardness is higher than that of copper, zinc tin, gold and silver, but lower than that of chromium and rhodium. Bright nickel has high chemical stability in air and good stability to alkali. Using Brightener on stainless steel pipe, bright nickel can be directly plated without polishing so as to improve the hardness, wear resistance and leveling of the surface, make the appearance of stainless steel pipe consistent with other nickel plated parts, and avoid the corrosion of potential difference between stainless steel pipe and other bright nickel. After using bright nickel solution for a period of time, due to the of brightenerThe resistance, linear coefficient thermal conductivity, quality, hot melt and magnetism of stainless steel pipe will change greatly at low temperature. Resistance, line coefficient decreases at low temperature; The thermal conductivity and mass heat capacity decrease sharply at low temperature; Young's modulus (longitudinal modulus) increases when the temperature decreases. Because the austenitic series stainless steel pipe has MS point (martensite start temperature or martensite formation temperature) at low temperature (subzreo temperature), martensite can be formed when it is kept below MS point. The formation of martensite at low temperature makes the representative steel sus (Cr-Ni) of austenitic stainless steel non-magnetic at room temperature and magnetic at low temperature.Stress corrosion cracking (SCC) refers to the cracking caused by the combined action of stress corrosion stress (mainly tensile stress) and corrosion of austenitic stainless steel Austenitic stainless steel is prone to stress corrosion in corrosive media containing chloride ions. When the Ni content reaches % - %, it is a long-term enterprise engaged in stainless steel plate, stainless steel coil, stainless steel belt and stainless steel pipe. Welcome to consult. The stress corrosion tendency of austenitic stainless steel is very large. Continue to increase the Ni content to ~ %, and the stress corrosion tendency gradually decreases until it disappears.Where is good,In many construction sites, we use this kind of welding for priming, which can effectively ensure its quality and has certain construction difficulties. Therefore, careful and skilled welders should be selected for this work.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, nuclear and food industries.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.

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 fastSales Department,Corrosion resistance of decorative stainless steel pipe the price of different series of stainless steel materials varies greatly. The corrosion resistance of more economical materials can not meet the higher application requirements, and the improvement of corrosion resistance of stainless steel materials by simple chemical passivation is limited. On the other hand, the traditional passivation treatment containing chromium salt has been gradually eliminated, and the passivation treatment of stainless steel has turned to the direction of environmental friendliness. Recently, citric acid passivation and silicon treatment on stainless steel surface have become a new research direction. The former has environmental protection characteristics because its passivation solution component does not contain chromium salt. The latter has found that silicon coupling agent is chemically adsorbed on the metal surface to form a protective silicon film with cross-linked network structure. The length of discoloration time of samples after different surface treatments was compared by blue dot method, the corrosion rate of samples after different surface treatments was distinguished by brine immersion test, and the salt spray resistance of samples after different surface treatments was distinguished by neutral salt spray test, The differences of pitting corrosion resistance and resistance to corrosive medium of samples after different surface treatment were compared by electrochemical test. The film thickness of silicon film was indirectly characterized by film weight test, and scanning electron microscope, energy spectrometer, X-ray diffraction X-ray photoelectron spectroscopy and total reflection Fourier transform infrared spectroscopy characterized the surface films of different surface treated samples, stainless steel coil, stainless steel belt stainless steel pipe, high price, service, on-site settlement, honest management! At present, there are few studies on the combination of citric acid passivation and silicon treatment of stainless steel. Therefore, this paper studies the difference of corrosion resistance of martensitic stainless steel Cr chemical passivation, silicon treatment and the combination of citric acid passivation and acid silicon system treatment, and discusses the corrosion resistance mechanism of different films on its surface, which can provide reference for the new direction of stainless steel surface treatment, It has certain practical guiding significance. The corrosion resistance and mechanism of chemical passivation, silicon treatment and composite treatment of martensitic stainless steel were studied in this paper. The comprehensive comparison of the research results shows that the corrosion resistance of stainless steel treated with different surface treatments is different. The corrosion resistance of the sample treated with silicon alone is better than that treated with traditional dichromate passivation. The corrosion resistance of the composite treated sample treated with citric acid passivation and acid silicon system is further enhanced than that treated with acid silicon system alone. The composite treatment of citric acid passivation and acid silicon system treatment has excellent corrosion resistance and environmental protection characteristics, the surface silicon film weight of the composite treated sample after citric acid passivation and acid silicon system treatment is lower than that of the sample after acid silicon system treatment alone, indicating that the excellent corrosion resistance of the composite film not only depends on the surface silicon film, but also benefits from its double-layer film structure.Corrosion test: the industrial corrosion-resistant steel pipes provided shall be tested for corrosion resistance according to the standard provisions or the corrosion agreed by both parties, s stainless steel pipe professional L stainless steel pipe, L stainless steel pipe and other special products, old brands,Santiago-de-las-VegasRose gold stainless steel plate, with advantages in price and guaranteed quality. We can use the following four kinds of backing welding.Santiago-de-las-Vegas,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.Only soluble paper or the combination of soluble paper and blocking plate is used for blocking ventilation protection (i.e. solid core welding wire + TIG + water-soluble paper)The slab solidified on the surface continues to be rapidly cooled through the secondary cooling section until the core becomes solid, and the whole continuous casting process of stainless steel pipe fittings is completed.