D. do not cut your hands boring， especially for girls. Holding or fingers will bind themselves.
0Stainless steel qb square pipe for mechanical structure， Standard No.: gbt-. Representative material Cr cr crni CrNi crninb， etc. It is mainly used for machinery， automobile， bicycle，Seamless square tube furniture，Galvanized square pipe production line equipmentMaintenance features of hotel and restaurant decoration and other mechanical parts and structural parts.
oStage ( & mdash; )
Cutting: to be fast no teeth， or whether the cutting line is flat， the starch taste of oil affects the quality of dishes. First choose to cut potatoes with less sharp bottom， so when you cut， its easy to leave the corner of the side end.
SBeijingThe square tube can be sprayed with fluorocarbon paint， which needs some treatment before spraying.
OlProcess flow of square tube drawing: because the size of the die hole of the square tube drawing is smaller than the outer diameter of the tube in front of the drawing， in order to make the front end of the square tube pass through the die hole smoothly， so that the clamp jaw of the drawing trolley can the head of the square tube， it is necessary to sharpen the head of the square tube before drawing. Therefore，Seamless square tube the end of the square tube with a fixed length should be heated in the slit heating furnace， It is generally ~ mm， and the heating temperature is between ~ ℃ according to different wall thickness. Then use ~ kg air hammer to sharpen and grind the head of the square pipe. Generally， the square pipe with diameter less than mm can be sharpened by rotary forging hammer or roll forging machine.
Now in many construction projects， because qb square tube is quite hard in hardness， and the performance and quality of deformation， stamping， cutting and other processing are based on hardness， which is also the guarantee of mechanical properties. Based on the above， it is very important to test the hardness of qb square tube.
Square pipe，Seamless square tube is referred to as square pipe and rectangular pipe for short. The allowable deviation of wall thickness of square pipe is f and J qb respectively. When the wall thickness is no more than mm， it shall not exceed plus or minus % of the nominal wall thickness. Long term square pipe，Galvanized square pipe production line equipmentMaintenance features of rectangular pipe seamless square pipe， galvanized square pipe， galvanized pipe， old brand， price advantage and quality guarantee! When the wall thickness is greater than mm， it is plus or minus % of the wall thickness， except for the wall thickness of corners and weld areas.
dImprove the positioning and pre bending steps， if necessary，Galvanized pipe_ Galvanized square pipe_ Seamless steel pipe_ Square tube - Wuxi Jiahang to ensure that the web hunting problem does not occur when pressing parts. Change the shape of the surface pressure of the material to ensure the quality of the parts and avoid the non movement of the surface shape of the roll gap， resulting in uneven walking feeding.
QAt 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.
GDirect laborTherefore， the drawing process of square tube is quite meticulous. For a long time， square tube， rectangular tube， seamless square tube， galvanized square tube， square tube has also been processed more rigorously.
uWSquare pipe is a square steel pipe cold drawn from seamless steel pipe， which is not a straight qb square pipe， and qb square pipe， also known as welded pipe， is a square pipe welded by steel plate or strip steel after crimping. Qb square tube has the advantages of simple production process， high production efficiency， many varieties and specifications and less equipment. The commonly used materials are QA and QC.
Upper yield point (& sigma; Su): the large stress before the yield stress of the sample decreases; Lower yield point (& sigma; SL): the small stress in the yield stage when the initial instantaneous effect is not considered.
Square pipe， the steel pipe whose ratio of outer diameter to wall thickness is less than is called square pipe. At present the square tubes produced by qb square tube factory are mainly used in tap water engineering， petrochemical industry， chemical industry， electric power industry agricultural irrigation and urban construction. For transportation: water supply and drainage. For gas transmission: gas， oil steam and liquefied petroleum gas. For structure: as pile driving pipe
wholesalerwThe 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， natural gas， heating and other pipelines.
DTool derusting mainly uses tools such as steel wire brush to polish the surface of square pipe， which can remove loose or oxidized scale， welding slag， etc. The derusting of manual tools can reach grade SA and that of power tools can reach grade SA. If the square pipe surface is firmly attached with iron oxide scale， the derusting effect of tools is not ideal and can not reach the anchor depth required by construction.
Now， Fangguan can achieve such good results in the market， which is completely inseparable from the manufacturers hard work in technology. I believe that the Fangguan market will be better and better in the future.
iThe raw material for rolling square tube is round tube blank. For a long time， square tube， rectangular tube， seamless square tube， excellent quality and favorable price. The round tube embryo shall be cut and processed by cutting machine， and the blank with a growth of about m shall be brought to the furnace for heating. The billet is sent to the furnace for heating at a temperature of about degrees Celsius. The fuel is hydrogen or acetylene. The temperature in the furnace is the key problem. After the round tube billet is discharged from the furnace， it should be pierced through the pressure piercer. Generally， the more common piercer is the conical roll piercer. This piercer has high production efficiency， good product quality， large perforation expansion and can wear a variety of steel grades.
aWDrawing 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. Lets understand it below.
The performance advantage of square tube after calcium treatment requires not only high strength， but also good machining performance. For sulfur-containing square tube， sulfur can improve the machinability of steel， 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.