After chemical pickling
The disadvantage of solid bending is that it has tensile thinning effect. The actual bending will produce tension at the bending point， the square tube can be well protected by electrolysis. These are simple ways to prolong the service life of the square tube， We only need to treat according to these， so that the square tube can bring us great help in the use process. The cold galvanized square tube is the principle of cold galvanizing on the square tube used to make the square tube have corrosion performance. Different from hot-dip galvanizing， cold galvanizing coating is mainly carried out according to the electrochemical principle. Therefore， it is necessary to ensure the sufficient of zinc powder and steel， resulting in electrode potential difference， so the steel surface treatment requirements are very high.
Staya daroshiThe cutting surface of the square tube shall be true circle， and the cutting line shall be at right angles to the axis of the square tube. Excessive force is the reason for cutting the square tube into flat or oval， so the square tube should be cut with appropriate force.
Generally speaking， square pipe welding has a process: ignition， pressurization and thermal insulation.
BrckoGenerally speaking， square pipe welding has a process: ignition， pressurization and thermal insulation.
Square tube is an essential material for the construction and Realization of industrialization. It is widely used and has a wide variety. According to different section shapes， square tube is generally divided into sections， plates， pipes and metal products. In order to facilitate the production， ordering and supply of square tube and do a good job in operation and management， it is also divided into heavy rail， light rail， large section steel， small section steel and square tube cold bending Section steel， high-quality section steel， wire rod， medium and thick steel plate sheet steel， electrical silicon steel sheet， strip steel， seamless steel pipe， square pipe， welded steel pipe，Staya daroshiGalvanized square pipe 100x100， metal products， etc.
Steel pipe for geological drilling (yb-) is a steel pipe used by geological departments for core drilling. It can be divided into drill pipe， drill collar，Staya daroshiGalvanized square pipe 25， core pipe casing， sedimentation pipe， etc.
High pressure oil pipe for diesel engine (gb-) is a cold drawn square pipe for high pressure pipe of diesel engine system.
Electrochemical polishing: long specular gloss， stable process， less pollution and good durability. Suitable for mass production， imported products and public service products. Its processing technology is stable and the operation is simple.
If the test results of square tubes fail to meet the provisions of product standards， the unqualified ones shall be selected， and double the number of samples shall be taken from the same batch of square tubes for re inspection of unqualified items. If the re inspection results (including any index required by the test of the project) are unqualified， the batch of square tubes shall not be delivered. If the following inspection items fail to pass the preliminary inspection，Staya daroshiWhere are galvanized pipes， re inspection is not allowed: A. There are white spots in the low magnification; b. Microscopic.
safety requirements Stage ( & mdash; )
Section shape classification of large-diameter qb square tube square tube is classified according to section shape: simple section square tube & mdash& mdash; Square tube， rectangular tube and complex section square tube & mdash& mdash; Flower shaped square pipe， open square pipe， corrugated square pipe， special-shaped square pipe large-diameter qb square pipe surface treatment classification square pipe is divided according to surface treatment: hot-dip galvanized square pipe， electro galvanized square pipe， acid pickling square pipe， large-diameter qb square pipe purpose classification square pipe is classified according to purpose & mdash& mdash; Square tubes for decoration， machine tool equipment， machinery industry， chemical industry， shipbuilding， automobile， steel beam and column， special purpose， large-diameter qb square tube wall thickness classification， large-diameter qb square tube according to wall thickness Classification & mdash& mdash; Super large diameter qb square pipe， large diameter qb square pipe and thin-wall large diameter qb square pipe rectangular pipe are the names of square pipe and QB square pipe， that is， steel pipe with equal side length. It is made of rolled strip steel after process treatment. Generally， 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 pieces per bag. Qb square pipe， also known as square and rectangular cold-formed hollow section steel， is referred to as square pipe and rectangular pipe， code f and j respectively. The allowable deviation of wall thickness of qb square pipe shall not exceed plus or minus % of nominal wall thickness when the wall thickness is not greater than mm， plus or minus % of wall thickness when the wall thickness is greater than mm， except for the wall thickness of corner and welding joint area.
C. electric furnace steel: (a) electric arc furnace steel; (b) Electroslag furnace steel; (c) Induction furnace steel; (d) Vacuum consumable furnace steel; (e) Electron beam furnace steel.
It is the process of drawing the die hole of the rolled metal blank (shape， pipe， product， etc.) into a section to reduce the length and increase. It is mostly used for cold processing.
Welcome calls Welding is a synthetic gradient material， which can be used as solder to weld special-shaped materials in order to overcome the mismatch of chemical， mechanical and physical properties between base metals.
The difference between qb square tube and QA is that there are fewer impurities s and P and better low-temperature impact performance. From the welding point of view， when the impurity elements in the base metal are less， it is good for welding hot crack.
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， resulting in edge instability and concave， 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， billet or square tube Make materials of all shapes， sizes and properties we need.
Staya daroshiHardness QB square hardness is a pointer to measure the hardness and softness of metal materials. At present， the hardness method is commonly used to measure the hardness in production. It uses the indenter with fixed geometry to measure the hardness value of the metal material surface tested under fixed load according to the degree of hardness.
Engaged in square tube， square rectangular tube， seamless square tube galvanized square tube， galvanized tube， old brand price advantage and quality guarantee! However， the Demander shall cut off the interface pipe when using it. The weight of short length and non fixed length products shall not exceed % of the total delivery. For qb square pipe with theoretical weight greater than kgm， it shall not exceed % of the total delivery. The bending degree of qb square pipe shall not be greater than mm per meter， and the total bending degree shall not be greater than .% of the total length. Galvanized qb square pipe for low-pressure fluid transmission， with standard number of gbt-. Representative materials: QA， qbqb， etc. It is mainly used for conveying water， air， oil and heating hot water or steam， and its purpose is limited to general low pressure fluid.
It is the process of drawing the die hole of the rolled metal blank (shape， pipe， product， etc.) into a section to reduce the length and increase. It is mostly used for cold processing.
