When we understand the causes of defects in the drawing process of q355b square tube, we should constantly improve the technology in the subsequent production process, so that we can reduce the occurrence of defects.
Now, Fangguan can achieve such good results in the market, which is completely inseparable from the manufacturers' hard work in technology. I believe that the Fangguan market will be better and better in the future.
Raleigh.Because the green billet can be pressed into any shape, it is easy to weld the square tube into difficult products.
At present, square tubes also have many good properties, strong corrosion resistance and heat resistance, and are widely used in many scientific and technological fields. Therefore, even so, wise people still do not stop studying the surface adhesion resistance of square tubes. Square tubes in the future will have better performance and make more important contributions to development.
.Sample length L & asymp; D (D is the outer diameter of the pipe). When the outer diameter is large, the length l shall not exceed 100mm. When the outer diameter is less than 20mm, l = 20mm.
Electrochemical polishing: long specular gloss, stable process, less pollution and good durability. Suitable for mass production, it is mainly applied to high-grade products, imported products and public service products. Its processing technology is stable and the operation is simple.
Spray fluorocarbon paint after.
Shot blasting is a high-speed rotating impeller that throws small steel shot or small iron shot out and hits the surface of the square tube at high speed, so the oxide layer on the surface of the square tube can be removed. At the same time, resulting in lattice distortion and deformation on the surface of the square tube and increasing the surface hardness
Oil drilling pipe (yb528-6) 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, and non turning wire pipe is connected with tool joint by butt welding.
The normal process flow is as follows: the round steel is perforated to form a tube embryo, then pickling is carried out, the black skin on the outer surface is washed off, and then grinding is carried out. After passing the inspection, the rolling mill or cold drawing and cold drawing are carried out. Annealing is required for wall reduction, but not for air drawing. After forming, annealing and straightening are carried out, and pickling is tested and stored in the warehouse. Basically, these are the processes. Better manufacturers will perform whitening treatment during annealing to make the surface treatment more beautiful. The narrow blank of square pipe can produce welded pipe with larger diameter, and the blank of the same width can also produce welded pipe with different diameter. However compared with the straight seam square pipe with the same length, the weld length increases by 60%, and the production speed is low. Square pipes with large or thick diameter are usually made of steel blank directly, while small welded pipes and thin-walled welded pipes only need to be directly welded with steel strip. Then after simple polishing, wire drawing is OK. Therefore, and spiral welding is mostly used for large-diameter welded pipes.
build.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.
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.
The researcher's test before using the strip thinning drawing also confirmed that using the strip thinning drawing can greatly reduce the large value of tangential residual stress of the drawn parts and effectively prevent the occurrence of longitudinal cracking. According to different deformation degree and original sheet thickness, the appropriate thinning coefficient & psi is selected; N (generally 0.9t ~ 0.95t), if & psi; If n is too small, the deformation stress will increase sharply, the requirements are more stringent. For example, hot furnaces are divided into heating furnace and reheating furnace according to their functions; The former is used to heat the blank from normal temperature to processing temperature; The latter is used to reheat the blank to the necessary processing temperature during processing.
Improve the positioning and pre bending steps, to ensure that the web hunting problem does not occur when pressing parts. Change the shape of the surface pressure of the material to ensure the quality of the parts and avoid the non movement of the surface shape of the roll gap resulting in uneven walking feeding.
Upper yield point (& sigma; Su): the large stress before the yield of the sample occurs and the stress 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.
Raleigh.The surface hardening treatment of qq355b square tube is generally isothermal quenching, that is, heat treatment technology. After isothermal quenching, qq355b square tube will obtain more and better properties, and make qq355b square tube be applied in more fields.
The standard number of spiral square pipe (standard of the Ministry of petroleum) for low pressure transmission is syt5037-2008. The representative materials are q235bq345b and other carbon steel materials. It is mainly used for low-pressure transmission of water, oil, natural gas, heating and other pipelines.
The q355b square tube protective layer thickness detector is used to measure the actual thickness of the seamless q355b square tube protective layer on site. It is required that the actual thickness of the seamless q355b square tube protective layer of the seamless q355b square tube shall not be lower than the design value. When the requirements are not met, the protective layer of seamless q355b square tube can be chiseled and measured.