Bao Steel Co., Ltd. is located in Zhengzhou, Kinmen and Matsu South Fourth Ring steel market, business friendly fever dip galvanized steel and plastic-lined steel pipe (plastic composite pipe), specifications for DN15-200, length 6 m YHI Group is the world's top 500 enterprises, product quality by the Chinese People's Property Insurance Company, the lifting of customers to worry about the quality of products as well as related issues in order to improve the corrosion resistance of the steel pipe, galvanized steel pipe for the general. Galvanized steel hot galvanized and electro-galvanized two, thick galvanized hot dip galvanized, electro-galvanized low cost, surface is not very smooth. Note the mechanical properties of the steel is to ensure that the steel end-use properties (mechanical properties) is an important indicator, it depends on the chemical composition and heat treatment system of steel. In the steel standard, depending on the application requirements, the provisions of the tensile properties (tensile strength, yield strength or yield point elongation) and hardness, toughness index, as well as user requirements of high and low temperature properties. Galvanized pipe steel grades: Q215A; Q215B; Q235A; Q235B test pressure /Mpa:D10.2-168.3mm for 3Mpa; D177.8-323.9mm for 5Mpa galvanized pipe galvanized pipe is the molten metal. The reaction with the iron matrix and the alloy layer, so that the substrate and coating combination of both. Hot dip galvanized steel is first pickled, the steel surface in order to remove iron oxide, after pickling, cleaning by a mixed aqueous solution of ammonium chloride bath or an aqueous solution of zinc chloride or ammonium chloride and zinc chloride, and then into hot dip tank. Has galvanized coating uniformity, strong adhesion, long life and other advantages. Steel substrate and the molten bath complicated physical, chemical reaction, the formation of corrosion-resistant compact structure of zinc-iron alloy layers. Alloy layer and the pure zinc layer, integrated steel substrate. So its resistant to corrosion. Pingdingshan a uniformity of zinc coating: steel sample solution * Copper dipped five times in a row may not turn red (copper color) 2, surface quality: galvanized steel surfaces should have a complete zinc coating shall have not plated spots and bubbles exist, allowing a little rough surface and the presence of localized tumors zinc. 3, zinc coating weight: According to the requirements, galvanized steel pipe can be used for measuring the weight of the zinc layer, the average value of not less than 500g / square meter, of which not less than any sample 480g / sqm. Now gas, greenhouse, heating with the kind of iron pipe is galvanized pipe, galvanized pipe as water pipes, a large amount of rust inside the tube, not only pollute the water flowing yellow ware, and mixed with non-smooth inner wall of the breeding of bacteria, corrosion caused by water heavy metal content is too high, serious harm to human health. Sixties and seventies, the international developed countries have started to develop new pipe, galvanized pipe and gradually disable. Chinese Ministry of Construction has issued four ministries explicitly disabled galvanized pipe from 2000 onwards, the new district currently has little use cold water pipe galvanized pipe, and some residential hot water pipes using galvanized pipe. Galvanized steel has the following production steps: black pieces hanging material inspection → → → degreasing → rinsing pickling → washing → dipping fluxing agent hot air drying → → → → cooling of hot-dip galvanized passivation and rinsing → discharging → test trimming → packaging and storage, transportation. 1, galvanized steel grades and chemical composition of steel grades and chemical composition shall conform to GB 3092 under the clarinet steel grades and chemical composition. Luohe galvanized pipe 2, a manufacturing method clarinet (furnace brazed or welded) selected by the manufacturer. Galvanized hot dip galvanizing method. 3, threaded fittings and threaded delivery 3.1 galvanized steel, thread should be galvanized after car system. YB 822 threads shall comply with the provisions of. 3.2 steel pipe fittings shall comply with the provisions of YB 238; malleable iron pipe fittings shall comply with the provisions of YB 230. 4, in front of the mechanical properties of galvanized steel shall conform to the mechanical properties of GB 3092. 5, the uniformity of galvanized steel galvanized zinc coating layer should be uniformity test. * Copper pipe sample solution impregnated five times in a row may not turn red (copper color). 6, cold bend test is not more than 50mm nominal diameter galvanized pipe should be cold bend test. Bending angle is 90 °, bending radius of 8 times the outer diameter. Without filling the test, the sample should be placed outside of the weld or the upper bending direction. After the test, the sample should not have cracks and peeling of the zinc layer with like. 7, hydrostatic testing hydrostatic test shall be carried out in clarinet, eddy current testing can also be used instead of the hydrostatic test. Test pressure or eddy current testing comparing the sample size should be consistent with the provisions of GB 3092. Mechanical properties of steel is to ensure that the steel end-use properties (mechanical properties) is an important indicator, it depends on the chemical composition and heat treatment system of steel. In the steel standard, depending on the application requirements, the provisions of the tensile properties (tensile strength, yield strength or yield point elongation) and hardness, toughness index, as well as user requirements of high and low temperature properties. ① tensile strength (σb) samples during stretching, the pull-off exposure to the most vigorous (Fb), the original cross-sectional area of ??the specimen to the stress (σ) (So) income, known as tensile strength (σb), in units of N / mm2 (MPa). It represents a metal material to resist damage under tension maximum capacity. The formula is: Where: When Fb-- specimen pull off exposure to the most vigorous, N (Newton); So-- original specimen cross-sectional area, mm2. ② metal material yield point (σs) having a yield phenomenon, the specimen during the tensile force is not increasing (constant) could continue stress elongation, called yield point. If power down occurs when, should distinguish between the lower yield point. Unit yield point of N / mm2 (MPa). The yield point (σsu): sample yield and maximum stress occurs first drop before; lower yield point (σsl): When excluding the initial transient effects, the yield phase of the minimum stress. Yield point is calculated as follows: Where: Fs-- process of tensile yield strength (constant), N (Newton) So-- original specimen cross-sectional area, mm2. ③ Elongation (σ) in the tensile test specimens fractured its gauge the increase in the percentage of the length of the original gauge length, called elongation. With σ expressed in units of%. The formula is: where: L1-- specimen fractured gauge length, mm; L0-- original specimen gauge length, mm. ④ section shrinkage (ψ) in the tensile test, the sample volume and reduce the percentage of the maximum diameter of the cross-sectional area of ??the original cross-sectional area of ??the fractured its contraction, known as section shrinkage. Ψ expressed in units of%. Calculated as follows: where: S0-- original specimen cross-sectional area, mm2; S1-- specimen fractured necking at least cross-sectional area, mm2. ⑤ hardness index metal material to resist indentation capacity hard objects surface, called the hardness. Depending on the test methods and scope, can be divided into Brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, micro-hardness and high temperature hardness. Pipe commonly used for Brinell, Rockwell, Vickers hardness of three. A, Brinell hardness (HB) with a certain diameter steel balls or carbide ball, test force (F) pressed into the surface of a predetermined pattern, after removing the holding time specified test force, measuring the sample surface indentation diameter (L). Brinell hardness test force is divided by the surface area of ??the resulting indentation spherical providers. With HBS (ball), said unit N / mm2 (MPa). Plastic composite pipe products to seamless steel tubes, welded steel pipes for the base, wall painting high adhesion, corrosion, hygienic food grade polyethylene powder coating or epoxy paint. Use of pre-treatment, preheating, inside painting, leveling, reprocessing galvanizing process within the water made plastic composite pipe, galvanized pipe upgrade traditional products, plastic composite pipe is generally used to connect a new thread The composite pipe pipe, steel pipe called a lot of places. Steel is an iron material; plastic means plastic, plastic composite tubes are generally high-density polyethylene plastic (HDPE). Plastic composite pipe [2] There are many categories, can be classified according to the structure of the pipe: steel reinforced plastic composite pipe, seamless steel reinforced plastic composite pipe, steel plastic composite pipe network hole and steel mesh skeleton-plastic composite pipe. Currently, the market is the most popular steel reinforced plastic composite pipe, plastic composite pipe is, we often say that the structure of plastic composite pressure pipe, this pipe through the middle layer of high carbon steel butt welded curl forming strip layers, the inner and outer layer are high-density polyethylene (HDPE). This middle layer of steel pipe, tubing pressure so performance is very good, unlike the aluminum pressure is not high, the largest diameter pipe can do 63mm, maximum diameter steel pipe can be done 200mm, even larger; Because steel pipe in the middle layer is closed, so this steel pipe also has oxygen barrier effect, can be directly used for drinking water projects, while its inner and outer layer is a plastic material, with very good corrosion resistance. So excellent performance, making plastic composite pipe very versatile, oil, natural gas, mining pipe, various fields of drinking water pipes, drains, etc. can see this pipe figure. Steel reinforced plastic composite pipe production process more complicated. Unlike aluminum strip, it is almost no flexibility, so the strip molding process requires very high. Secondly, the strip is usually thicker than the aluminum can not be used welding lap welding process, only use high precision butt welding process. Finally, even if the steel is processed into full compliance with the requirements of the steel pipe, what kind of technology to make the perfect combination of steel and PE, has become another plastic composite pipe manufacturing problems. After years of research and experiments, Pipe Co., Ltd. Changzhou Tengda research to overcome all these difficulties in 2000, making the production process of plastic composite pipe popular in the world, the Ministry of Construction in 2003 introduced the CJ / T183-2003 "plastic composite pressure Tubes "Although steel reinforced plastic composite pipe with other pipe incomparable advantages, but the complexity and demands of the sophisticated technology of its production process, so many pipe manufacturers prohibitive, so there will be a seamless steel pipe reinforced plastic composite pipe, steel plastic composite pipe network hole and steel mesh skeleton plastic composite pipe appears these types of pipe.