Raw materials The selection of materials shall comply with the relevant standards of the pipe production country and the raw material standards required by the owner. After entering the factory, the inspectors first verify the original material certificate issued by the manufacturer and ...

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Vacuum heat treatment equipment began in the 1920s, but its real development began in the 1960s and 1970s, mainly due to the market demand and the development of graphite technology. The working environment of vacuum heat treatment is: It is lower than a standard atmospheric pressure ...

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Although the small bolt is not impressive, it is used as a fastener to connect the key parts of the automobile in series. Once the corrosion fracture failure occurs, it will lead to vehicle failure in light and casualties in heavy cases. According to the website of the State Administration of marke ...

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In the design, manufacture, use and repair of fixture, problems often occur due to improper selection of materials and heat treatment, which affects the quality of products. When dealing with these problems, it is not only necessary to improve the material and heat treatment, but also to change the ...

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Why to test the content of oxygen, nitrogen and hydrogen in steel? The harm of oxygen Both oxygen and hydrogen have adverse effects on the mechanical properties of steel. It is not only the concentration of oxygen, but also the number, type and distribution of inclusions containing oxygen. Th ...

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At present, high and medium pressure valves with flange are widely used in petrochemical system. The valve body is the main part of the valve. According to American Petroleum Association (API) specification for wellhead and Christmas tree equipment, the oil valve body is often required to work unde ...

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In 316L austenitic stainless steel produced by laser powder bed fusion (l-pbf), the cellular structure formed by rapid solidification plays an important role in achieving high strength and high ductility. However, the understanding of their intrinsic properties (such as crystal orientation, dis ...

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Can carbon steel Q235 and stainless steel be welded together? The answer is as follows:  1. To be sure, it can be welded and belongs to the welding of dissimilar steels. 2. According to the material of stainless steel, choose stainless steel electrode to weld stainless steel and carbon ...

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Valve inspection and installation Inspection before valve installation ① Carefully check whether the valve model and specification meet the drawing requirements. ② Check whether the valve stem and disc open flexibly and whether there is jamming and deflection. &# ...

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In other words, fixed point machining requires three points and one fixed point. There are many reasons for the deformation of common aluminum parts, which are related to the material, the shape of parts and the production conditions. There are several aspects: deformation caused by internal stress ...

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Introduction to stainless steel Generally speaking, stainless steel is not easy to rust steel, in fact, some stainless steel, both stainless steel and acid resistance (corrosion resistance). The rust resistance and corrosion resistance of stainless steel are due to the formation of chromium ...

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What is shrinkage porosity? Shrinkage porosity refers to that the final solidification area of the casting is not fed by liquid metal or alloy to form dispersed and small shrinkage cavity. Often scattered in casting The axis area of wall thickness, the thick part, the root of ri ...

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