The strip caused by component segregation, that is, when the steel contains harmful impurities such as phosphorus and is pressed and delayed, the impurities elongate along the rolling direction. When the steel is cooled below 4, making the morphology of ferrite distributed in bands, and then pearlite distributed in bands. This band can be eliminated by electroslag remelting and increasing crystallization speed.
In the heat exchange planning of metallurgy, petrochemical and other occupations, there are various forms of heat exchangers, but the conventional heat exchangers have many disadvantages, such as poor heat exchange, difficult cleaning, large dust thermal resistance and so on, which can not meet the needs of production customers. The square tube heat exchanger based on square tube throat has the advantages of excellent heat exchange, easy cleaning, small dust thermal resistance and compact structure.
Corpus-Christi.With the improvement of production quality, the quality of square tubes is getting better and better. The quality of square tubes will affect our lives. Because the functions of square tubes are different, it is necessary to distinguish the carbon equivalent of the q355b square tube, and the carbon equivalent of the q355b square tube is the same. If the carbon equivalent of Q345 is less than 0.3%, it can be said that the weldability is OK. Generally speaking, the cold crack increases when the carbon equivalent is 0.4%.
.Square pipes are mainly used in engineering buildings, glass curtain walls, door and window decoration, steel structures, guardrails, machinery, automobiles, shipbuilding, containers, electric power, agricultural construction, bicycle frames, motorcycle frames, shelves, fitness equipment, leisure and tourism, steel furniture, various specifications of oil casing, oil pipes and pipeline pipes, water, gas, sewage, air Heating and other fluid transportation, fire fighting and support, construction and other fields.
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.
After chemical treatment and surface treatment of the square tube, the appearance and quality of the square tube have been improved to another height, making the current square tube present in the market in a good state.
Drawing process flow of square tube in the production process of square tube, it needs a lot of processes to complete the production process, so that the production quality of square tube can be more strictly guaranteed. This paper mainly introduces the drawing process flow of square tube. Let's understand it below.
Normalized: A. pearlite steel; b. Bainitic steel; c. Martensitic steel; d. Austenitic steel.
Performance index analysis of square tube - strength refers to the performance of metal materials under static load. Since the action modes of load include tension, compression, bending and shear, the strength is also divided into tensile strength, compressive strength, flexural strength and shear strength. There is often a certain between various strengths. Generally, tensile strength is used as the basic strength indicator.
Service first.In order to ensure the stability of the perforation performance and chemical properties of the billet of the square tube, the technical regulations shall be strictly implemented in the operation of the circular furnace, the operation of the heating furnace shall be frequently, the abnormal conditions shall be handled in time and recorded, and the follow-up posts and quality management department shall be notified in time for handling.
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 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 advantages of real bending are small reverse, the R of inner corner forming is more accurate. The disadvantage of solid bending is that it has tensile thinning effect. The actual bending will produce tension at the bending point and as long as the roll shape is accurate, and the tensile effect will shorten the longitudinal length of the bending line; The metal at the real bend will become thinner due to stretching.
A complete range of products.Square tube is the main type of square tube. It is also very popular in the square tube market. There are many people doing this kind of thing, so there are many in the competition. The future market potential is huge. We should grasp this information well. In addition, we must learn about relevant maintenance and repair!
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.
The advantages of real bending are small reverse, accurate forming, and as long as the roll shape is accurate, the R of inner corner forming is more accurate. The disadvantage of solid bending is that it has tensile thinning effect. The actual bending will produce tension at the bending point and the tensile effect will shorten the longitudinal length of the bending line; The metal at the real bend will become thinner due to stretching.
Corpus-Christi.In the standard of q355b square tube, most of them specify tensile test and hardness test at the same time. For those materials that are not convenient for hardness test, such as q355b square tube, only tensile test is specified. In particular, the new portable surface Rockwell hardness tester and pipe Rockwell hardness tester can quickly and accurately test the hardness of stainless steel plate, stainless steel strip and q355b square tube as thin as 0.05mm, which makes it easy to solve the problems that were difficult to solve in China in the past.
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.
Square tube industry plays an important role in production and construction. Square pipe is a steel pipe made of a whole piece of metal without joints on the surface, which is called square pipe.