After aluminum deoxidation in molten steel， & omega; When (ALS) is .% ~ .%， calcium treatment can achieve better effect on the denaturation of Al.
5High productivity of square tube: the efficiency of cold production of mechanical parts is very high， especially for parts with large batch. Cold production can be several times， several times or even hundreds of times higher than cutting. For example， the use of cold pin for automobile is twice higher than that of cutting. At present，Rectangular Pipe cold pin automata is used to improve productivity. The productivity of table cooling automata is equivalent to that of ordinary lathes or shaft self-propelled machines.
mGreatly reduce the structural weight and save steel. Square tube is an indispensable part of construction work，140 square tubeQuality inspection method which we all know very well. Therefore， the quality of square tube will directly affect the development of construction industry. What if we can make the service life of square tube longer? Here， we also need to ask the personnel of the square tube manufacturer for instructions， and use ingenious methods to prolong the service life of the square tube， so that the square tube can bring us greater help in life.
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.
TRio GallegosThere are several kinds of color qb square tubes: high temperature oxidation method， chemical oxidation method， electrochemical oxidation method， ion implantation method and gas phase cracking method.
PuAfter the square tube is cut into a single square tube the head and root of each batch of square tube shall be subject to strict first inspection. The mechanical properties，Rectangular Pipe fusion condition chemical composition， surface quality of square tube and NDT shall be carried out to ensure that the pipe making process is qualified before it can be officially put into production.
HDPE plastic square pipe made according to the properties of square pipe has the advantages of light texture， high strength， good resistance， easy laying， low water resistance， low cost and corrosion resistance. Its service performance and economic benefits far exceed reinforced concrete pipe and general specification iron pipe. It is an updated product of engineering pipe.
Tensile test is to form seamless qb into a sample， pull the sample to fracture on the tensile testing machine， and then measure one or more mechanical properties. Usually， only tensile strength，Rectangular Pipe yield strength， elongation after fracture and reduction of area are measured.
gCold 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，140 square tubeQuality inspection method improve material rate and improve product quality.
EThe performance advantage of square tube after calcium treatment requires not only high strength， but also good machining performance. For sulfur-containing square tube， so the sulfide inclusion in square tube is the key to determine the quality of steel. Sulfur mainly exists in the form of MNs in the steel. The single MNS inclusion is light black strip. The inclusion with this morphology cuts off the continuity of the steel matrix and makes great differences in the anisotropic properties of the steel. Calcium treatment of molten steel can form MNS inclusions and combine MNS with al CAS to form composite spindle inclusions. Such inclusions can improve the machinability of steel and avoid the adverse impact of MNS inclusions on the properties of steel.
USampling inspectionDimensional stability for high-precision square tubes， the required accuracy is high， so the dimensional stability must be maintained. Due to straightening in the air and slow cooling speed， it has the effect of stabilization and will increase the number of residual square tubes in the， so it must be cooled; Reduce quenching deformation because the square tube is slender， it is easy to deform during quenching，Square pipe, square rectangular pipe, seamless square pipe, galvanized square pipe, galvanized pipe - Wuxi Jiahang metal products Co., Ltd so its deformation must be strictly controlled. Heat treatment is a key process. In the process of quenching and cooling， the cold plasticity shall be corrected in time， which is a key step to ensure the improvement of its qualification rate. Therefore， square tubes and thin-walled square tubes according to wall thickness. Gbt-gbt-gbt- JG -， ASTM A， JIS gen or technical agreement.
The standard number of spiral square pipe (standard of the Ministry of petroleum) for low pressure transmission is syt-. The representative materials are qbqb and other carbon steel materials. It is mainly used for low-pressure transmission of water， oil， natural gas， heating and other pipelines.
The standard number of square pipes for transporting flammable and non flammable fluids is gbt (gbt - represents steel for l-l and other pipelines. It is mainly used for transporting flammable and non flammable fluids， low-pressure or high-pressure square pipes， with high requirements.
StatisticsjIn terms of hot working， repeated upsetting and multi-directional rolling of ingot can not only reduce the level of carbide segregation in square tube， and then made by hot rolling and it is difficult to achieve the desired results in some fine cracks.
Square tube is made of steel ingot or solid tube blank through perforation， cold rolling or cold drawing. Square pipe plays an important role in steel pipe industry.
gAfter the square pipe is produced， the surface treatment is generally carried out， that is， the scale， rust， there are a lot of demands for project construction， which leads to the continuous increase of square pipe. The of square pipe is more complex. Great efforts should be made in the selection of raw materials， structured treatment and so on.