High temperature diffusion heat treatment of ingot can improve the composition heterogeneity of ingot and improve the transverse performance of square tube.
When cutting the sample, the surface of the sample shall not be damaged, the properties of the metal shall not be changed due to heating or cold processing, and the edges at the section shall be rounded.
San-Ramon.Square tubes are classified by forming: forged steel; Cast steel; Hot rolled steel; Cold drawn steel.
Classification of wall thickness square tubes are divided into super square tubes, square tubes and thin-walled square tubes according to wall thickness. Gbt6728-200gbt6725-200gbt3094-2000, JG 178-200, ASTM A500, JIS g34en10210 or technical agreement.
.Among them, q355b square tube is divided into 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 are divided by weld & mdash& mdash; Straight seam welded square pipe, spiral welded square pipe.
Square pipe is the name of square pipe, that is, steel pipe with equal side length. It is made of rolled strip steel after process treatment. Generally, the strip steel is unpacked, leveled, crimped and welded to form a round pipe, then rolled into a square pipe from the round pipe, and then cut into the required length. Usually 50 pieces per bag.
Ordinary carbon steel is divided into Q19 Q2 q23 SS400, 20# steel, 45# steel, etc.
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, Standard No.: gbt97 1 (gbt97 - 1997). The representative material is l245-l4 pipeline steel. It is mainly used to transport flammable and non flammable fluids. Low pressure or high pressure square pipes have high requirements. The purpose of large-diameter q355b square pipe is q355b square pipe, C-shaped steel and H-shaped steel. It is mainly used in the construction of simple plant steel structure and other infrastructure. Q355b square pipe is generally used as the frame and purlin of the plant. C-shaped steel Steel is an important support for the plant, and H-section steel is used as load-bearing. Especially in recent years, a large number of small and medium-sized enterprises have started to build spacious and bright plants. If traditional buildings are built, the time is slow, the work progress is affected, and the investment is large. For some small and medium-sized enterprises, if the investment in the plant is too high, the capital will be produced after operation Serious impact. The plant built with q355b square tube, C-section steel and H-section steel has the characteristics of time saving, money saving and fast use. Therefore, the sales of q355b square tube, C-section steel and H-section steel have increased significantly in recent years and become the first choice for plant construction. Q355b square tube, C-section steel and H-section steel are mainly used in the construction of simple plant, a large number of small and medium-sized enterprises around the country have started to build spacious and bright plants. If the traditional buildings are built, the time is slow the work progress is affected, and the investment is large. For some small and medium-sized enterprises Said that if the investment in the plant is too high, it will have a serious impact on the capital after operation. The plant built with q355b square pipe, C-section steel and H-section steel has the characteristics of time saving, money saving and fast use. Therefore, the sales of q355b square pipe, C-section steel and H-section steel have increased significantly in recent years, becoming the first choice for plant construction. Large diameter q355b square pipe plant is introduced Shao measures for effective wrinkle of seamless square pipe: check the wrinkle state, even when the wrinkle around the part is determined to be less than the clamping force, and the gradual increase of the roll gap force can be. When drawing the cone and hemispherical components, it should be increased to increase the inner diameter of the inner plate and the tensile stress of the wrinkle drawbead. Adopt the principle of loosening after tightening to loosen after tightening and ask Question.
Galvanized q355b square pipe for low pressure fluid transmission, Standard No.: gbt3092-2008. The representative material is the same as above. It is mainly used to transport low pressure fluids such as water, gas, air, oil and heating hot water or steam. The surface of square pipe adopts hot galvanizing or cold galvanizing process.
Latest consultation.In order to ensure excellent coating quality, the coating is required to be firmly attached to the surface of the coated object. This depends on the quality of the coating itself; On the other hand it depends on the quality of the coated surface treatment before construction. After various surface treatments, the coating quality and economic effect are very different.
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, these impurities become the core of ferrite, 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.
However, there is a large rate of end in the application of steel pipe, which is mainly due to the trouble of internal and external treatment. The first question is very crucial, and the external quality is good or bad
Chemical polishing: less investment in processing equipment, high speed, high efficiency and good durability. Its defects are poor brightness, gas overflow, demand for ventilation equipment and difficult heating. It is suitable for processing small batch of disordered parts and products with low brightness demand for small parts.
how.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.
Ferrous metals refer to iron and iron alloys. Such as steel, pig iron, cast iron, etc. Steel and pig iron are alloys based on iron square tube and carbon as the main added element, collectively referred to as iron carbon alloy.
It is learned from the authority that if there is dirt on the outer surface of the square pipe during degreasing, it can be washed with purified water and dried naturally, then soaked with degreasing agent with a dry cloth to remove the oil, and then dried in the open air. When degreasing the inner surface of the opposite pipe, the end of the pipe can be tightly blocked with a wooden plug or closed with other. The degreasing solvent with the volume of 15% - 20% of the pipe from the other end shall be sealed with a wooden plug, placed in a flat and clean place or on a workbench with sleepers for 60-80min, and the pipe shall be rotated every 20min. If degreasing is required for stainless steel elbow, degreasing solvent shall be appropriately added to make it fully soaked. After degreasing, pour out the solvent in the pipe, dry the pipe with exhaust fan, or dry it with oil-free compressed air or nitrogen or dry it with natural air. Large diameter pipes can be manually scrubbed with cotton cloth dipped in solvent; The square tube can also be soaked in a long tank containing solvent for 60 to 80 minutes. The concentrated pipeline and equipment of the concentrated unit can be directly pumped and circulated with 88% concentrated for pickling after all installation. Pipes that cannot circulate or are not resistant to concentrated corrosion must be degreased separately.
San-Ramon.It is feasible to use the theory to calculate static structures, such as warehouses, houses and bridges, but it is not suitable for moving components such as wheels. At this time, people often use the plastic theory. The research of the plastic theory can be traced back to 1914. In 1975 the European Design Association formulated a plastic design code, which is mainly used for static load plane beams and frame structures subjected to bending stress The solution is as follows: for high-rise buildings, more detailed calculations are needed.
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, 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