To sum up, improving the quality level of square tube is the key to ensure the service life of die. Therefore when the economic cost and equipment conditions permit, the quality level of square tube, including surface quality and internal quality, should be improved as much as possible by using more mature process measures.
The test can be carried out under cold and hot conditions. If the test temperature is not specified, the test shall be carried out under normal temperature, but not lower than - 10 ℃.
Tulzia cimpia turzii.The general delivery length of q355b square pipe is 4000mm-12000mm, or in the form of interface tube
In different environments, 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, contraction, meandering, shear and so on, because the strength is also divided into tensile strength, compressive strength, flexural strength, shear strength and so on. There is often a definite connection between various strengths. In normal use, tensile strength is often used as the fundamental strength gauge.
In the case of dynamic load, plastic design usually calculates the allowable stress according to the safety factor that the allowable stress is not less than the dynamic load and multiplied by the allowable stress. In the case of bending of an axis, it can be calculated by the formula a = W. replacing the calculated strength with plasticity can improve the bearing capacity of the member by 14%.
At the same time, the heating temperature and heating time will also have a great impact on the performance of square tube. The heating of square tube blank is the key process to ensure that the square tube blank has enough plasticity and complete the smooth perforation. If the heating temperature is too high or the heating time is too long, the billet of the square tube will be burned and decarburized, and even the chemical composition of the square tube will be unqualified (unqualified carbon content), which is easy to cause batch quality problems and seriously affect the product qualification rate.
To sum up, improving the quality level of square tube is the key to ensure the service life of die. Therefore, the quality level of square tube, including surface quality and internal quality, should be improved as much as possible by using more mature process measures.
Stage (1961 & mdash; 1978)
Q355b square tube, the selected die material, has obvious hardening in the deep drawing process, resulting in many hard metal points, resulting in adhesion. Special products such as professional square tube, square rectangular tube, seamless square tube, galvanized square tube and galvanized tube are 20-year-old brands, with advantageous price and guaranteed quality. It makes the surface of workpiece and die easy to scratch and wear, so tool steel for general die can not be used.
Quality assurance.There are many forms of heating furnace, but the ring heating furnace is mainly used. The heating furnace has an annular furnace bottom, which can rotate slowly, the blank is loaded along the diameter direction of the furnace bottom from the inlet, and the heating operation especially needs patience. Because if the heating operation is not standardized cracks, folding and eccentricity on the inner or outer surface of the tube blank will only produce waste products and defective products.
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.
With the development of economy, there are a lot of demands for project construction, 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.
Dimensional stability for high-precision square tubes, the required accuracy is high, so the dimensional stability must be maintained. Due to straightening in the air and slow cooling speed, it has the effect of stabilization and will increase the number of residual square tubes in the, so it must be cooled; Reduce quenching deformation because the square tube is slender, it is easy to deform during quenching, so its deformation must be strictly controlled. Heat treatment is a key process. In the process of quenching and cooling, the cold plasticity shall be corrected in time, which is a key step to ensure the improvement of its qualification rate. Therefore, hot bath quenching or cooling in oil for a fixed time shall be carried out to propose thermal correction.
Discount.The common surface treatment of square pipe includes surface treatment, chemical treatment, shot blasting treatment, manual mechanical treatment and flame treatment. The treated will be separated. 4 ~ 6Mpa compressed air entrains abrasives, and the nozzle sprays to the steel surface at high speed. The impact and friction of abrasives remove the oxide scale rust and dirt on the steel surface, and make the steel surface reach a certain roughness.
Improve the positioning and pre bending steps, if necessary, 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.
Large diameter welded square pipe for low pressure fluid transmission Standard No.: gbt14980-1994. Representative material: q235ab grade. It is mainly used to transport low-pressure fluids, such as water, sewage, gas air and heating steam.
Tulzia cimpia turzii.Various treatments are summarized as follows: high temperature oxidation method is to immerse the workpiece in a specific molten salt and maintain a fixed process temperature
To change the required line shape of q355b square tube, it is necessary to forge the impact force of q355b square tube hammer or the pressure of hydraulic press, and can also enhance the malleability of q355b square tube, that is, the performance of changing the shape without cracks.
Tensile test is to form seamless q355b into a sample, and then measure one or more mechanical properties. Usually, only tensile strength, yield strength, elongation after fracture and reduction of area are measured.