The test can be carried out under cold and hot conditions. If the test temperature is not specified， the test shall be carried out under normal temperature， but not lower than - ℃.
2Before gas cutting， remove the dirt and grease on the steel surface， and leave a certain space below to facilitate the blowing out of slag. During gas cutting， the movement of the cutting torch shall be kept at a uniform speed. The distance between the surface of the cutting part and the flame core shall be ~ mm. If the distance is too close，镀锌方管 the edge of the cut will melt， and if it is too far away， the cutting will be interrupted due to insufficient heat.
rC. 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.
After the square pipes are stacked and stored， which is difficult to volatilize.
MUlan BatorThe welded joints of square pipes are subject to on-line continuous ultrasonic automatic flaw detector to ensure the NDT coverage of spiral welds. If there are defects， it will automatically alarm and spray marks. The production will adjust the process parameters at any time to eliminate the defects in time.
ZiWith the development of economy， 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.
Cutting: to be fast， no teeth， or whether the cutting line is flat，镀锌方管 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.
Therefore， QA is usually not preheated. However， when the plate is very thick it should be preheated because it cools quickly. Once # steel was cracked by J welding. If the plate thickness is more than mm， there is a great risk of not preheating.
wA. square tube structural steel: (a) high quality carbon structural steel; (b) Alloy structural steel; (c) Spring steel; (d) Easy cutting steel; (e) Bearing steel; (f) High quality structural steel for specific purposes.
MThe welded joints of square pipes are subject to on-line continuous ultrasonic automatic flaw detector to ensure the NDT coverage of spiral welds. If there are defects， it will automatically alarm and spray marks. The production will adjust the process parameters at any time to eliminate the defects in time.
Ahow muchStainless steel qb square pipe for mechanical structure Standard No.: gbt-. Representative materials Cr cr crni CrNi crninb， etc. are mainly used for mechanical parts and structural parts such as machinery， automobile， bicycle，镀锌方管 furniture， hotel and restaurant decoration.
bHHowever， there is a large rate of end in the application of steel pipe， and its external quality is very important
With the progress of the times， square tubes are used in more and more fields and their scope of use is obviously increasing， which makes us have many kinds of square tubes. At this time， we need to store square tubes reasonably. Customers should also learn to arrange reasonably when storing square tubes. Lets understand how to store square tubes correctly.
Galvanized qb square pipe for low pressure fluid transmission， Standard No.: gbt-. The representative materials are the same as above. It is mainly used for conveying low-pressure fluids such as water， gas， air and oil and heating hot water or steam. The surface of square pipe shall be hot galvanized or cold galvanized.
marketbIn the processing process，方管,方矩管,无缝方管,镀锌方管,镀锌管-无锡嘉航金属制品有限公司 the processing temperature is the key. We specialize in selling square tubes， rectangular tubes， seamless square tubes， galvanized square tubes. Galvanized tubes have advanced technology， strict testing， we must pay attention to the uniform heating of blanks. Perforation has a great impact on the quality. The perforation temperature of blank varies according to different materials， generally around ℃.
PSquare tube is made of different materials. It needs qualified inspection by relevant staff before leaving the factory. Square tube has a wide range of uses. Its main field is not only the construction industry， but also can be seen everywhere in our daily life. The service life of square tubes is mainly affected by surface treatment. I will explain the specific operations of surface treatment of square tubes.
Low alloy steel is divided into q Mn， Q， St-， etc.
aWhen we understand the causes of defects in the drawing process of qb square tube， we should constantly improve the technology in the subsequent production process， so that we can reduce the occurrence of defects.
hBClassification of surface treatment square pipe is divided into hot-dip galvanized square pipe， electro galvanized square pipe， oiled square pipe and pickled square pipe according to surface treatment.
The inclusions in the square tube treated with calcium can be denatured well， and the morphology of sulfide in the rolled stock is also improved.