Fatigue strength, plasticity and hardness discussed above are indicators of the mechanical properties of metals under static load. In fact, many machine parts work under cyclic load, under which fatigue will occur.Cold drawn or cold rolled precision square tube (gb-) is a cold drawn or cold rolled precision square tube with high dimensional accuracy and good surface finish for mechanical structure and hydraulic equipment. The selection of precision square mechanical structure or hydraulic equipment can greatly save machining hours,In terms of hot working repeated upsetting and multi-directional rolling of ingot can not only reduce the level of carbide segregation in square tube, but also improve the anisotropy of steel.In this period, the technology of continuous rolling pipe was not mature.Vulcanesti,Hot dip galvanized square tube is a kind of square tube which is welded after using steel plate or steel strip to curl and form, and on the basis of this square tube, the square tube is placed in the hot dip galvanized pool and formed through a series of chemical reactions; The production process of hot-dip galvanized square pipe is relatively simple, but the production efficiency is very high and there are many specifications and varieties, but this kind of square pipe needs little equipment and capital, which is more suitable for the production of small galvanized square pipe manufacturers.Reinforcing phases such as reinforcing particles, ethylene, phenolic and other coatings commonly used for square pipes, the surface of square pipes is generally required to reach near white grade (SA). Practice has proved that almost all oxide scale rust and other dirt can be removed by using this derusting grade, and the depth of anchor grain can reach ~ & mu; m,Car slopeSquare tube galvanizing plant, which fully meets the requirements of adhesion between layer and square pipe The shot derusting process can meet the technical conditions of near white level (SA) with low operation cost and stable and reliable quality.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 %, 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, straight seam welding is mostly used for relatively welded pipes, and spiral welding is mostly used for large-diameter welded pipes.The disadvantage of empty bending is that when the upper side and side are synchronously empty bending, the forming force is easy to exceed the critical point due to the pressure generated by the upper roll and the lower roll at the same time, and will also affect the stable operation and forming quality of the unit. This is also the different characteristics of qb square tube and round tube empty bending. The concept of square tube: square tube is the pressure processing of ingot,Car slopePP square tube, sizes and properties we need.technical service,Square tube for automobile half shaft sleeve (gb-) is a high-quality carbon structural steel and alloy structural steel hot-rolled square tube for automobile half shaft sleeve and drive axle housing.C. special performance steel: (a) stainless and acid resistant steel; (b) Heat resistant steel; (c) Electric heating alloy steel; (d) Electrical steel; (e) High manganese wear resistant steel.Brinell hardness (HB), Rockwell hardness (HRC) and Vickers hardness (HV) are commonly used.

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.Installation requirements,QB square tube is a product appeared in recent years, which mainly has strict tolerance and roughness for the dimensions of inner hole and outer wall. Production process classification of large-diameter qb square tube large-diameter qb square tube is divided into hot-rolled seamless square tube,Car slope30 unit price of galvanized square pipe, cold drawn seamless square tube, seamless square tube and qb square tube according to production process. 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; Material classification of straight seam welded square pipe and spiral welded square pipe large diameter qb square pipe: plain carbon steel square pipe and low alloy square pipe. Ordinary carbon steel is divided into Q Q q SS, # steel, # steel, etc; Low alloy steels are divided into q Mn, Q St-, etc.When processing the square tube, some processes need to heat the seamless square tube. The heating operation in the processing of the seamless square tube plays a very key role in the quality of the finished seamless square tube.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.Car slope,There are many processing technologies for square tubes. I won't introduce the specific processing technology here. We only know about the processing technology of each other's tubes. We may have insufficient understanding of its heating technology. Next, I'll give you a detailed introduction to the heating technology of the lower tubes.High density may not be obtained by simple pressurization, and insulation shall be carried out at the same time.At this time, if the welding wire of the same material is used for spot welding where the thickness is insufficient, it shall be welded to the fixed thickness, ground and sandblasted, and repair welding shall be adopted where there are cracks, even if the steel pipe with another large opening can be made up at one time.