Tangshan special square tube manufacturers directly supply wholesale manufacturers
Seamless square tubes pass through the tube blank sawing section of the steel mill, and then are heated - perforated - sized - straightened - cooled - slugged - packaged in the annular furnace to become qualified waste products. Generally, it is impossible to place so many stock items in the consumer workshop when they are sent to the user, which requires dealers to place some stock items. However, dealers generally do not have large indoor warehouses, and some costs are too high, which is not cost-effective. Most of them are outdoor warehouses. If the seamless square tubes are placed outdoors, they will be exposed to the wind and the sun. The so-called floating rust literally means a layer of rust floating on the seamless square tube, which can be removed with a towel or other things. Simply speaking, floating rust is also considered as no rust, which belongs to the normal state. The rusting of seamless square tubes is a long-term problem. At least for more than one year, the seamless square tubes that have been exposed to the wind and the sun outside have large and small pits on them, which is the only difference between the floating rust and rusting of seamless square tubes.
Tangshan special square tube manufacturers directly supply wholesale manufacturers
Due to the different properties of seamless square and rectangular tubes, the behaviors reflected by the data are different; The mechanical performance indicators are all performance indicators under the static seamless square tube. Whether in the static tensile test or hardness test, the seamless square tube is slowly added to the sample or workpiece. However, in consumption practice, many workpieces accept the impact of seamless rectangular tubes, that is, seamless rectangular tubes act on workpieces at a great speed, such as the hook between train carriages when the train starts or stops. When the gear is shifting; The seamless square and rectangular tubes that the forging die and the stamping die are subjected to when they are working belong to this category. The difference between the impact seamless square tube and the static load is that the static load is simply the function of force, while the impact seamless square tube has the speed problem of force besides the function of force. Since it is extremely complicated to measure the impact stress on the workpiece under the impact seamless rectangular tube, it is convenient to think about the problem from the concept of energy, so the impact seamless rectangular tube can be regarded as an energy seamless rectangular tube. Due to the different nature of seamless square tube, the behavior reflected by the data is also different. The deformation and destruction process of the data under the impact of seamless rectangular tube is still elastic deformation, elastic seamless rectangular tube deformation and fracture, but the loading speed has a great influence on these three stages, especially the deformation of seamless rectangular tube. Due to the demand time for seamless rectangular tube deformation after the data is stressed, the deformation of seamless rectangular tube in the data may not be carried out in time with the increase of loading speed, which is manifested in the fall of deformation ability of seamless rectangular tube in the data and the increase of deformation resistance of micro seamless rectangular tube such as elastic limit and yield limit. Secondly, under the impact of the seamless square tube, the uneven or partial deformation of the plastic matrix of the data is more prominent than that under the static load. The deformation of the seamless square tube is likely to be limited to a small range, and it will lead to cracks and fractures here. This uneven deformation of the seamless square tube further limits the development of the deformation of the seamless square tube of the data. Therefore, in general, the impact seamless rectangular tube has a tendency to promote data embrittlement. The data with large deformation ability of seamless rectangular tube under static load may become very small and brittle under impact of seamless rectangular tube.
Tangshan special square tube manufacturers directly supply wholesale manufacturers
1. During square forming, the corner bending is related to the neutral layer of the strip steel. The inner corner is pressed and the outer corner is pulled. No matter what method you use for square forming, the result of the corner force is that the outer tensile strip steel is thinner. From the physical phenomenon, the metal lattice changes and cold work hardening occurs. Especially when the general pass strip is hard, the corner may be broken. In addition, the dimensional accuracy of the straight square is mostly handled by sizing: first, it increases the equipment load; second, the steel strip also produces local cold work hardening, which affects the internal quality of the profile. 2. During the round to square forming, the main pipe is compressed and deformed in the pass. The pass design considers the elastic limit of the base metal, that is, the pressure must not exceed the elastic limit. If the elastic limit is exceeded, the base metal will "lose stability" and form waste products. It can be seen that the physical phenomenon of round to square forming does not change the strip. In addition, the contour and dimensional accuracy of the round to square shape is guaranteed by the hole type and adjustability, so its contour dimensional accuracy is high. Moreover, because the deformation of round to square is stopped under pressure, the thickness of its corner has an increasing trend instead of thinning, and the load resistance of profiles with the same thickness and the same specification can be significantly improved compared to the straight square.
Tangshan special square tube manufacturers directly supply wholesale manufacturers
In order to understand the process law of direct squaring, it is necessary to understand the forming principle of bending. Both rectangular tube and round tube are formed by rolling, but there are great differences in the forming object, forming request and forming force between them. In order to understand the principle of direct squaring, the tube forming method is called bending; The forming method of rectangular tube is called bending. (Broadly speaking, bending is also bending. Bending and bending are distinguished here in order to understand that bending changes the curvature during tube forming and bending changes the angle during direct square forming.) Bending and bending are different. (1) Forming object The bending object of different round tubes is a line segment, and the bending object of square tubes is a point (in practice, the bending point of square tubes is a small area where the inner corner R is unfolded); (2) Different requirements for forming - the curvature of the line segment is changed when the circular tube is bent, and the included angle of the adjacent side is changed when the square tube is bent (3) The forming force is different - the forming force for bending is centripetal force, and the forming force for bending is bending moment.
