Impact toughness the load acting on the machine part at a great speed by QB is called impact load, and the ability of metal under impact load is called impact toughness.Impact toughness the load acting on the machine part at a great speed by QB is called impact load,(& sigma; Su): the large stress before the yield stress of the sample decreases for the first time; Lower yield point (& sigma; SL): the small stress in the yield stage when the initial instantaneous effect is not considered. The calculation formula of yield point is as follows: where: FS -- yield force (constant) in the tensile process of the sample, n (Newton) so -- original cross-sectional area of the sample, the percentage of the length increased by the gauge length of the sample after breaking to the original gauge length is called elongation.There are many ways of ignition, such as arc, electric spark, flame, strong current, high-temperature furnace, electron beam, laser, high-temperature radiation, microwave, chemical furnace, etc.Loum,Alloy steel: A. low alloy steel (total alloy element content & le; %); b. Medium alloy steel (total alloy element content > ~ %); c. High alloy steel (total alloy element content > %). special shaped square pipe is the general name of square pipes with other cross-section shapes except circular pipe. According to the different cross-section shape and size of steel pipe, it can be divided into special-shaped square pipe with equal wall thickness (code D), special-shaped square pipe with unequal wall thickness (code BD) and special-shaped seamless steel pipe with variable diameter (code D) These special-shaped large-diameter qb square tubes are widely used in various structural parts, tools and mechanical parts. Compared with circular tubes, special-shaped tubes generally have large moment of inertia and section modulus, and have large bending and torsion resistance, which can greatly reduce the structural weight and save steel. Square tubes are an indispensable part of construction work. fake and inferior square tubes are easy to fold. Folding is a variety of broken lines formed on the surface of square tubes, and this defect often runs through the longitudinal direction of the whole product. The reason for the folding is that the fake and shoddy manufacturers pursue the rate, the reduction is too large, resulting in ears, folding occurs during the next rolling, the folded products will crack after bending, and the strength of the square tube will be greatly reduced.

Reinforcing phases such as reinforcing particles, short fibers and whiskers can be added to the solder to form composites.First, remove the deposits on the surface of the square pipe surface with copper wire brush. Use the perfume oil or other scrubbing oil on the surface layer,San Jose60 galvanized square pipe, or use phosphate or chromate solution, brush, spray or dip coating. After the fixed reaction time, rinse the acid solution with plenty of fresh water on the surface.The reason why it is divided into two types is that chemical cleaning can only clean the surface very thoroughly, and it is difficult to achieve the desired results in some fine cracks.Installation material list,Square pipe welding is suitable for surface treatment of materials. Square pipe welding can be used for ceramic ceramic, metal ceramic and metal metal welding.The inspection items, 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.Square tube has a wide range of application fields. Its main field is the construction industry, which promotes the development of economic construction. Because the production process of square tube hole is different, the production design of square tube hole is also different. Next, I will introduce in detail the types of tube hole design below.

Comprehensive classification ordinary steel A. carbon structural steel: (a) Q (b) Q (b); (c) Q( C)； (d) Q( B)； (e) Q.new product,Precision inner diameter square tubes for hydraulic and pneumatic cylinders (gb-) are cold drawn or cold-rolled precision square tubes with precision inner diameter for hydraulic and pneumatic cylinders.Square pipes are mainly used in engineering buildings, glass curtain walls, door and window decoration steel structures, guardrails, machinery, household appliances, shipbuilding, containers, electric power, agricultural construction, agricultural greenhouses, 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.Square tube heating process square tube calculates the chip thickness of workpiece. After each regrinding, the service life of the saw blade. Regrinding times of the saw blade. When the saw blade is replaced,San JoseGalvanized special-shaped square pipe, the main drive AC motor spindle rotates stepless speed change AC motor feed capacity stepless speed change feed fast return to a constant value center system brush device hydraulic saw cutting system system system represents the quality RA flatness large burr height cutting Chip length tolerance dimension: width and length . ~ .mm ~ m ~ ~ min kW ~ rpm ( kw ~ mmmin mmmin .kw .kw & times; kW S & mu; m . mm & plusmn; mm about mm about mm about mm high. The total weight of each billet square tube is seconds (including, pipe blank cutting,San JoseGalvanized square pipe, saw blade return, opening device, pipe blank discharge, head and tail cutting time, but excluding pipe blank transportation time). The large production capacity of the three saws is T / A. the pipe blank saw has a special reversing device (hydraulic servo device) to reduce vibration and improve the service life of the saw (only during feeding). The sawing machine has two devices distributed at the inlet and outlet (the input area is supported by roller table to ensure the bending of billet) The inlet end after sawing. Open it to ensure that the saw blade does not contact the blank when it returns. & mdash; feed saw gear & mdash; saw gear vibration reduction, which is composed of a fixed gear vibration reduction, as a movable vibration reduction to avoid the axial of the saw blade. & mdash; brush and sweep device & mdash; a driving brush and sweep device is installed at the bottom of the saw blade to clean the iron filings on the teeth and will not affect the service life of the saw blade. &Mdash; saw blade. In order to improve the service life of the saw blade a small amount of high load agent container is atomized by air and poured on the saw blade without residue. & mdash; saw blade cooling device. A special nozzle is used to spray cold air at - oC on the saw blade. The cut-off blank is transferred to the buffer chain in front of the loader after passing through the outlet roller table and weighing device (Note: # before sawing, there is a feeding bench for single size billets that need to be cut, and after weighing, there is a feeding bench for returned billets). The buffer transfer chain transports the billets to the lower roller table of the loader. The billets are turned over from the chain to the roller table by the turnover hook. The weighed qualified billets are loaded into the annular furnace by the loader, and the weighed unqualified billets are transported from the roller table to the removal bench for removal.San Jose,We all know very well. Therefore, the quality of square tubes will directly affect the development of the construction industry. What if we can make the service life of square tubes longer? Here, we also need to ask the personnel of the square tube manufacturer for instructions, 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 so that the square tube can bring us greater help in life.QB square tube is a product appeared in recent years, 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), # steel, # steel, etc; Low alloy steels are divided into q Mn, Q, St-, etc.The square tube is divided into a. boiling steel according to the degree of deoxidation and pouring; b. Semi killed steel; c. Killed steel; d. Special killed steel. The deformation of qb square tube is mainly caused by the shrinkage force of the weld greater than the strength of the base metal.