Functional index analysis of square tube - commonly used are square tube Brinell angle (HB)， Rockwell angle (HRC) and Vickers angle (HV). Angle is a gauge needle to weigh the soft and hard level of metal data. The angle method is rarely used to determine the internal angle in the current life. It uses the metal data surface tested under the fixed load of the indenter with a certain number and shape to determine its angle value according to the level of the object.
3Section shape classification square tube is classified according to section shape: simple section square tube: square tube， rectangular square tube.
vThe technology of floating mandrel and square tube is gradually mature.
Ordinary carbon steel is divided into Q Q q SS， # steel， # steel， etc.
TWaubzhehGalvanized qb square pipe for low pressure fluid transmission，方矩形管 Standard No.: gbt-. The representative material is the same as above. It is mainly used to transport low pressure fluids such as water，125 galvanized welded pipeNew preferential quotation gas， air， oil and heating hot water or steam. The surface of square pipe adopts hot galvanizing or cold galvanizing process.
XuThe qb square tube protective layer thickness detector is used to measure the actual thickness of the seamless qb square tube protective layer on site. It is required that the actual thickness of the seamless qb square tube protective layer of the seamless qb square tube shall not be lower than the design value. When the requirements are not met， the protective layer of seamless qb square tube can be chiseled and measured.
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 raw material for rolling square tube is round tube blank. For a long time， square tube， rectangular tube，方矩形管 seamless square tube， galvanized square tube and galvanized tube have complete products， 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.
mFor transportation: water supply， drainage sewage treatment engineering， marine water transportation.
VThe 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 mud transportation，方矩形管 it will automatically alarm and spray marks. The production will adjust the process parameters at any time to eliminate the defects in time.
XresourcesIn the heat exchange planning of metallurgy， petrochemical and other occupations，125 galvanized welded pipeNew preferential quotation there are various forms of heat exchangers， but the conventional heat exchangers have many disadvantages， such as poor heat exchange， difficult cleaning， large dust thermal resistance and so on， which can not meet the needs of production customers. The square tube heat exchanger based on square tube throat has the advantages of excellent heat exchange， easy cleaning， small dust thermal resistance and compact structure.
oHMechanical polishing: after processing，鍍鋅管_鍍鋅方管_無縫鋼管_方矩管 -無錫嘉航 the parts have good levelness， short gloss， dull and rusty. Suitable for processing simple parts， medium and small products.
The common surface treatment of square pipe includes surface treatment， chemical treatment， shot blasting treatment， manual mechanical treatment and flame treatment. The treated will be separated. ~ Mpa compressed air entrains abrasives， and the nozzle sprays to the steel surface at high speed. The impact and friction of abrasives remove the oxide scale， rust and dirt on the steel surface， and make the steel surface reach a certain roughness.
To sum up， improving the quality level of square tube is the key to ensure the service life of die. Therefore， when the economic cost and equipment conditions permit， the quality level of square tube， including surface quality and internal quality， should be improved as much as possible by using more mature process measures.
reformbIn & sigma; Expressed in%. The calculation formula is: where: L -- gauge length after sample breaking， mm; L -- original gauge length of sample， mm. Reduction of area (& psi;) in the tensile test， the percentage between the large reduction of the cross-sectional area at the reduced diameter and the original cross-sectional area after the specimen is broken is called the reduction of area. In & psi; Expressed in%. The calculation formula is as follows: where: S -- original cross-sectional area of the sample， mm; S -- small cross-sectional area at the reduced diameter after sample breaking， mm.
MSteel used & mdash& mdash; Such as bridge steel ship steel， boiler steel pressure vessel steel， agricultural machinery steel， most of them specify tensile test and hardness test at the same time. For those materials that are not convenient for hardness test， such as qb square tube， only tensile test is specified. In particular， the new portable surface Rockwell hardness tester and pipe Rockwell hardness tester can quickly and accurately test the hardness of stainless steel plate， stainless steel strip and qb square tube as thin as .mm， there will be deformation， uneven incision and crack of the incision. What should we pay attention to when cutting the square tube and how to operate it? Today， please use a rag or cloth to clean the oil on the surface of the square tube Sundries or soil shall be completely clean.
wSVarious treatments are summarized as follows: high temperature oxidation method is to immerse the workpiece in a specific molten salt and maintain a fixed process temperature and time
In the standard of qb square tube， most of them specify tensile test and hardness test at the same time. For those materials that are not convenient for hardness test， such as qb square tube， only tensile test is specified. In particular， the new portable surface Rockwell hardness tester and pipe Rockwell hardness tester can quickly and accurately test the hardness of stainless steel plate， stainless steel strip and qb square tube as thin as .mm