NaranjoIs JDG 
HerediaDN25 gaPerformance index analysis of square tube - plasticity refers to the ability of metal materials to produce plastic deformation without deformation under load.
Structure: used as pile driving pipe and bridge; Pipes for wharf, road, building structure, etc. It is mainly used as petroleum geological drilling pipe, cracking pipe for petrochemical industry, boiler pipe, bearing pipe high-precision structural pipe for automobile, tractor and aviation, etc.
Drummondville.The principle of straightening machine is that a disc is divided into two sides to clamp round steel straight lines. Professional square tube, square rectangular tube, seamless square tube, galvanized square tube galvanized tube, high price, service, on-site settlement, honest operation! The edge is one with radius r, and the other outer edge must be two equal diameters with radius R2. The diameter of the reinforcement to be straightened is D, and automatic submerged arc welding is adopted for repair welding after rolling into square pipe.
.Spiral square pipe for low-pressure transmission (standard of the Ministry of petroleum), with the standard number of syt5037-2008. The representative material is q235bq345b and other carbon steel materials. It is mainly used for low-pressure transmission of water, oil, natural gas, heating and other pipelines.
The welding sequence is to reduce deformation. The welding sequence of rectangular butt welding shall adopt layered and symmetrical skip welding from the middle to both sides according to the following principles. The welding deformation is smaller than that of straight through welding, which is conducive to the dispersion and release of stress and avoid complex stress in weldments. During straight through welding, the narrow plastic deformation zone formed at the beginning of welding only occurs once. Moreover, the heat input is large, the heating area is large, and the plastic deformation area caused by compression is large, so the shrinkage deformation after welding is very large. In case of layered and segmented skip welding, the section of each layer is very small, and the heat required is small, and each layer is divided into several sections for skip welding. Each welding section basically re establishes the secondary temperature field on the cold steel plate, and a narrow plastic deformation zone appears each time. Therefore, the average width of the plastic deformation zone (i.e. the size of transverse shrinkage) is smaller than that of the corresponding layered straight through welding, and the longitudinal shrinkage is also smaller, The welding deformation is smaller than that of continuous filling.
After the square pipes are stacked and stored the pipe end protector shall be removed to avoid moisture gathering on the surface of the pipe end protector and the square pipe, which is difficult to volatilize.
The quality of the solid square tube after the square tube formwork removal and curing can be tested according to the requirements and the following ways: use a magnifying glass to observe whether there are non external force cracks on the structural surface of the solid seamless q355b square tube. When non external force cracks appear on the surface of q355b square pipe, the crack width on the structural surface of ordinary q355b square pipe shall not be greater than 0.20mm.
The disadvantage of solid bending is that it has tensile thinning effect. The actual bending will produce tension at the bending point, there are a lot of demands for project construction,DrummondvilleSpecification of galvanized square pipe, which leads to the continuous increase of square pipe. The of square pipe is more complex. Great efforts should be made in the selection of raw materials, structured treatment and so on.
Quality inspection report.The service life has a great impact on the isotropic performance of the square tube. The use of secondary refining technology (including vacuum refining, ESR and ladle powder spraying) can improve the purity of the square tube especially reduce the content of harmful impurities in the square tube, which is beneficial to improve the performance.
Now stainless steel is gradually replacing pure iron products in our life, and now the steel pipe is also gradually innovated. Now the q355b square pipe is a typical representative. However, the above small series are not the focus. Today,DrummondvilleGalvanized steel pipe hot dip galvanized steel pipe, the use efficiency of square tubes is different. According to the quality of square tubes, we will conduct progressive research on them, hoping to develop better square tubes. No matter what environment, we will make square tubes suitable for use. Then, what is the role of shot blasting and sand blasting in each other's pipe? Next, let's introduce it to you.
Hardness test is to determine the hardness of seamless q355b square pipe by slowly pressing a hard indenter on the sample surface according to the specified conditions, and then testing the indentation depth or size.
Quality Assurance.Spray fluorocarbon paint after.
After spraying (throwing) derusting, it can not only expand the physical adsorption on the pipe surface, but also enhance the mechanical adhesion between the layer and the pipe surface. Therefore, spray (throwing) derusting is an ideal derusting method for pipelines. Generally speaking, shot blasting (sand) is mainly used for the inner surface treatment of the pipe, and shot blasting (sand) is mainly used for the outer surface treatment of the pipe. Several problems should be paid attention to in derusting by spraying (throwing).
The square tube is a low-alloy high-strength structural steel with carbon content of 0.1% - 0.25%, and the main alloy elements manganese, vanadium, niobium and titanium are added; Its total alloy content is 3%. According to the strength, it is divided into four levels: 300, 350, 400 and 450MPa.
Drummondville.0 200× 200×0～ 0 220× 220×0～ 0 250× 250×0～ 0 280× 280×0～ 0 300× 300×0～ 0 320× 320×0～ 0 350× 350×0～ 0 380× 380×0～ 0 400× 400×0～ 0 420× 420×0～ 0 450× 450×0～ 0 480× 480×0～ 0 500× 500×Standard treatment of steps for preventing oxidation of 0 ~ 0 square tube square tube is a kind of metallic maintenance. The main components are iron and zinc. It is easy to have redox reaction in the air. Once the reaction occurs, many new substances have taken place, and the original characteristics have changed. However, in order to maintain the original relevant characteristics, anti-oxidation treatment is required. The direct reason is to prevent the square tube from reacting with the oxygen in the air, which is the way to isolate the oxygen in the air. Today, this article makes a relatively standardized treatment on the relevant steps to prevent oxidation of square tubes: the key depends on what kind of antirust paint you use. 1. If you use epoxy zinc rich or iron rich antirust paint, you can directly spray fluorocarbon paint on it; 2 if alkyd antirust or red lead is used, it shall be cleaned with paint remover and sprayed with epoxy zinc rich or iron rich antirust paint again before fluorocarbon paint can be sprayed.
According to the welding specification, process test and process analysis, it is determined that the butt weld of Q345B square pipe adopts double-layer CO2 gas shielded welding. H08Mn2SiA, 2mm welding wire for welding material; The shielding gas is pure CO2 gas. The welding current of layer weld is 200 ~ 250A, and that of the second layer is 240 ~ 320A; The arc voltage is 24 ~ 26V. The process requirement is that the layer weld must be fully welded to ensure good back forming; The welding current,Drummondville75 galvanized square pipe, arc voltage, wire feeding speed and welding speed can be adjusted according to the equipment model.
After the process of polishing, the surface effect of the square tube is quite good. The quality of the polishing process directly affects the external image of the square tube. Therefore we must choose the appropriate polishing according to the above, and pay more attention to the polishing process of the square tube.