and non turning wire pipe is connected with tool joint by butt welding.With the improvement of production quality

Oil drilling pipe (yb-) is a square pipe used for internal or external thickening at both ends of oil drilling. Steel pipes are divided into turning wire and non turning wire. Turning wire pipe is connected with joint, the quality of square tubes is getting better and better. The quality of square tubes will affect our lives. Because the functions of square tubes are different,Shi ChuqinGalvanized steel square pipe factory, their characteristics and uses are different. I will introduce the characteristics and uses of square tubes in detail.Shi Chuqin,The cutting surface of the square tube shall be true circle, and the cutting line shall be at right angles to the axis of the square tube. Excessive force is the reason for cutting the square tube into flat or oval, so the square tube should be cut with appropriate force.Square pipe for conveying flammable and non flammable fluids, Standard No.: gbt (gbt - ). The representative material is l-l pipeline steel. It is mainly used to transport flammable and non flammable fluids. Low pressure or high pressure square pipes have high requirements. The purpose of large-diameter qb square pipe is qb square pipe, C-shaped steel and H-shaped steel. It is mainly used in the construction of simple plant, steel structure and other infrastructure. Qb square pipe is generally used as the frame and purlin of the plant. C-shaped steel Steel is an important support for the plant,Shi ChuqinRepresentation of galvanized square pipe, and H-section steel is used as load-bearing. Especially in recent years, a large number of small and medium-sized enterprises have started to build spacious and bright plants. If traditional buildings are built, the time is slow, the work progress is affected, and the investment is large. For some small and medium-sized enterprises, if the investment in the plant is too high, the capital will be produced after operation Serious impact. The plant built with qb square tube, C-section steel and H-section steel has the characteristics of time saving, money saving and fast use. Therefore, the sales of qb square tube, C-section steel and H-section steel have increased significantly in recent years and become the first choice for plant construction. Qb square tube, steel structure and other infrastructure The qb square tube is used as the frame and purlin of the plant. The C-shaped steel is used as the important support of the plant, and the H-shaped steel is used as the load-bearing. Especially in recent years, a large number of small and medium-sized enterprises around the country have started to build spacious and bright plants. If the traditional buildings are built, the time is slow, the work progress is affected, and the investment is large. For some small and medium-sized enterprises Said that if the investment in the plant is too high, it will have a serious impact on the capital after operation. The plant built with qb square pipe, C-section steel and H-section steel has the characteristics of time saving, money saving and fast use. Therefore, the sales of qb square pipe, C-section steel and H-section steel have increased significantly in recent years, becoming the first choice for plant construction. Large diameter qb square pipe plant is introduced Shao measures for effective wrinkle of seamless square pipe: check the wrinkle state, even when the wrinkle around the part is determined to be less than the clamping force, and the gradual increase of the roll gap force can be. When drawing the cone and hemispherical components, it should be increased to increase the inner diameter of the inner plate and the tensile stress of the wrinkle drawbead. Adopt the principle of loosening after tightening to loosen after tightening and ask Question.New Caledonia , compression, bending and shear, the strength is also divided into tensile strength,Shi ChuqinQ235A galvanized pipe, compressive strength, flexural strength and shear strength. There is often a certain between various strengths. Generally, tensile strength is used as the basic strength indicator. Precision pipe is a seamless pipe with high dimensional accuracy and good surface finish for mechanical structure and hydraulic equipment. The selection of precision seamless mechanical structure or hydraulic equipment can greatly save machining hours, improve material rate and improve product quality. Seamless pipe is rolled in the annular pass composed of variable cross-section circular hole groove and fixed conical plug. Cold drawing is usually carried out on single chain or double chain cold drawing machine. This method is to put the heated pipe blank in a closed cylinder, and the perforated rod and rod move to extrude the part from the smaller die hole. This method can produce steel pipe with smaller diameter.During the pushing process of spot welding and repair welding elbows, there will be thinning, there are about wires thinned. If the technology is not good or the drawn pipe is used, the thickness is significantly lower than the standard.Square tubes are classified by forming: forged steel; Cast steel; Hot rolled steel; Cold drawn steel.

Square tube modified square tube, square tube, QB square tube and hot-rolled square tube are qualified in quality inspection. The manufacturer adopts advanced equipment to ensure the quality of each product. Magnetic flux leakage testing for surface defects of square tubes is very similar to magnetic particle testing for square tubes, and then the shaping unit will roll the round pipe into square pipe sensitivity and reliability are stronger than magnetic particle testing. Indirect square forming process the traditional forming process of cold-formed square pipe is to gradually roll the hot-rolled steel coil multi stand forming unit into round pipe at room temperature, which is called indirect square forming process. The traditional roll forming process uses the method of fixed bending point position and variable bending radian to complete the corner forming of pipe blank, which is suitable for rolling small and medium-sized products. Rolling with this process & ldquo; Superb & rdquo; Square tube will show its inherent defects. Because the roll work in the bending process of this process is always concentrated at the point, which will lead to cracking in serious cases. The products with such defects have serious consequences when they are used in building steel structures. The study of the broken square tube column in the Hanshin earthquake in Japan shows that the corner microcrack is the main cause of the square tube fracture. At the same time, due to the different forming bending radians of products with different wall thickness, the universality of rolls is limited. The large-size cold-formed square tube used in the process adopts the advanced & ldquo; Direct Square & rdquo; The production process is to directly roll the hot-rolled steel coil into a square and rectangular shape at room temperature.The butt joint between the head and tail of square pipe and strip steel adopts single wire or double wire submerged arc welding, and automatic submerged arc welding is adopted for repair welding after rolling into square pipe.If the test results of square tubes fail to meet the provisions of product standards, the unqualified ones shall be selected, and double the number of samples shall be taken from the same batch of square tubes for re inspection of unqualified items. If the re inspection results (including any index required by the test of the project) are unqualified, the batch of square tubes shall not be delivered. If the following inspection items fail to pass the preliminary inspection, re inspection is not allowed: A. There are white spots in the low magnification; b. Microscopic.Latest quotation,Hundreds of degrees Celsius, which can save energy.Classification of square pipe material square pipe is divided into ordinary carbon steel square pipe and low alloy square pipe according to material. Ordinary carbon steel is divided into Q Q q SS, # steel, # steel etc; Low alloy steels are divided into q Mn, Q, St-, etc.Among them, qb square tube is divided into: (a) by process & mdash& mdash; Arc welded square pipe, resistance welded square pipe (high frequency and low frequency), gas welded square pipe and furnace welded square pipe (b) are divided by weld & mdash& mdash; Straight seam welded square pipe, spiral welding

The inspection items, sampling quantity, sampling position and test of square tube shall be in accordance with the provisions of corresponding product standards. With the consent of the demander, hot-rolled square tubes can be sampled in batches according to the rolled root array.production,If the test results of square tubes fail to meet the provisions of product standards, the unqualified ones shall be selected, and double the number of samples shall be taken from the same batch of square tubes for re inspection of unqualified items. If the re inspection results (including any index required by the test of the project) are unqualified the batch of square tubes shall not be delivered. If the following inspection items fail to pass the preliminary inspection, re inspection is not allowed: A. There are white spots in the low magnification; b. Microscopic.(& sigma; Su): the large stress before the yield stress of the sample decreases for the first time; Lower yield point (& sigma; SL): the small stress in the yield stage when the initial instantaneous effect is not considered. The calculation formula of yield point is as follows: where: FS -- yield force (constant) in the tensile process of the sample, n (Newton) so -- original cross-sectional area of the sample, mm. Elongation after fracture (& sigma;) in the tensile test, the percentage of the length increased by the gauge length of the sample after breaking to the original gauge length is called elongation.If the re inspection results are unqualified (including the items whose preliminary inspection results are unqualified and re inspection is not allowed), the supplier can submit them for acceptance one by one; Or re conduct heat treatment (the number of RE heat treatment shall not exceed times), and propose acceptance with a new batch.Shi Chuqin,The appearance of fake and inferior square tubes often has pitting. Pockmarked surface is an irregular uneven defect on the surface of square lead pipe due to serious wear of rolling groove. Due to the pursuit of profit by fake and shoddy square tube manufacturers, the rolling of rolling groove often exceeds the standard.The difference between square pipe and seamless steel pipe the main feature of seamless steel pipe is no welding joint and can withstand large pressure. The product can be very rough as cast or cold drawn parts.After chemical pickling, the square tube can be well protected by electrolysis. These are simple ways to prolong the service life of the square tube, We only need to treat according to these, so that the square tube can bring us great help in the use process. The cold galvanized square tube is the principle of cold galvanizing on the square tube used to make the square tube have corrosion performance. Different from hot-dip galvanizing, cold galvanizing coating is mainly carried out according to the electrochemical principle. Therefore, it is necessary to ensure the sufficient of zinc powder and steel, resulting in electrode potential difference, so the steel surface treatment requirements are very high.