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.
Hardness test is to use a hard indenter to slowly the sample surface according to the specified conditions, and then test the indentation depth or size so as to determine the hardness of the material. Hardness test is simple, rapid and easy to implement in material mechanical property test. Hardness test is non-linear, and there is an approximate conversion relationship between material hardness value and tensile strength value. The hardness value of material can be converted into tensile strength value, which is of great practical significance.
KedzierzynKozle.Classification of square tube steel is iron carbon alloy with carbon content of square tube between 0.04% - 3%. In order to ensure its toughness and plasticity, the carbon content generally does not exceed 7%. In addition to iron and carbon, manganese, sulfur, phosphorus etc. There are various classifications of steel and square tubes, mainly including the following: square tubes are classified into ordinary steel according to quality (P & le; 0.045%, S & le; 0.050%)
Reach or even exceed the level of resistance welding cold formed square pipe. The size of R angle is generally between 2-3 times of the wall thickness. R angle square pipe of the size required by customers can also be produced according to customers' needs; Square pipe is a kind of long steel with hollow section and no joints around. It is a square pipe formed by four sides of seamless pipe mold. Square pipe has hollow section, professional square pipe, square rectangular pipe, seamless square pipe galvanized square pipe, galvanized square pipe, strict inspection and quality assurance. The preferential activity is in progress. Welcome to consult. A large number of pipes are used for conveying fluid. They are mainly used in conveying, hydraulic support and mechanical structure, Medium and low pressure, high pressure boiler tubes, heat exchange tubes, gas, oil and other industries. It is stronger than welded and will not crack.
.One of the steps that are prone to defects in the production of square tubes is heat treatment and the other is tensile treatment. Today we need to know the latter. Maybe some people will have a lot of questions about why square tubes are prone to defects in tensile. Now let's analyze the specific causes of defects.
Brinell hardness, Rockwell hardness and Vickers hardness are commonly used.
The welding sequence is to reduce deformation. The welding sequence of rectangular butt welding shall adopt layered and symmetrical skip welding from the middle to both sides according to the following principles. The welding deformation is smaller than that of straight through welding, which is conducive to the dispersion and release of stress and avoid complex stress in weldments. During straight through welding, the narrow plastic deformation zone formed at the beginning of welding only occurs once. Moreover, due to continuous welding the heat input is large, the heating area is large, and the plastic deformation area caused by compression is large, so the shrinkage deformation after welding is very large. In case of layered and segmented skip welding, the section of each layer is very small, and the heat required is small, and each layer is divided into several sections for skip welding. Each welding section basically re establishes the secondary temperature field on the cold steel plate, and a narrow plastic deformation zone appears each time. Therefore, the average width of the plastic deformation zone (i.e. the size of transverse shrinkage) is smaller than that of the corresponding layered straight through welding, and the longitudinal shrinkage is also smaller, The welding deformation is smaller than that of continuous filling.
Square pipe also known as square and rectangular cold-formed hollow section steel, is referred to as square pipe and rectangular pipe for short. The allowable deviation of wall thickness of square pipe is f and J q355b respectively. When the wall thickness is no more than 10mm, it shall not exceed plus or minus 10% of the nominal wall thickness. Long term square pipe, rectangular pipe, seamless square pipe, galvanized square pipe, galvanized pipe, 20-year-old brand, price advantage and quality guarantee! When the wall thickness is greater than 10mm, it is plus or minus 8% of the wall thickness, except for the wall thickness of corners and weld areas.
When storing Q345B square pipe, such as the corrosivity of steel pipe, etc. Therefore, the place must be clean, dry and ventilated, where harmful gases appear, Q345B square pipe can not appear, and the outer surface of steel should be kept clean. If there are acid, alkali, salt, it is easy to react with the steel pipe and corrode the steel pipe, if we can think about those higher metal products, there is a sealed warehouse, but the ventilation setting is excellent. The difference between Q345B square tube and seamless steel tube Q345B square tube is a kind of high-precision steel tube material after cold drawing or hot rolling treatment. Q345B square tube is mainly used to produce products of pneumatic or hydraulic components, such as air cylinder or oil cylinder, which can be seamless pipe or welded pipe, because there is no oxide layer on the inner and outer walls of Q345B square tube, no deformation under high pressure, high precision, high finish, cold bending, flaring and flattening without cracks. The chemical composition of Q345B square tube includes carbon silicon Si manganese Mn, sulfur s, phosphorus P and chromium CR.
On the basis of thermodynamic calculation, the quality assurance of square tube, rectangular tube, seamless square tube, galvanized square tube and galvanized tube is professional. New and old customers are welcome to consult during the preferential activities. The process conditions of calcium treatment of 20CrMo sulfur-containing square tube are analyzed, and the sulfur-containing gear rolled products after calcium treatment are sampled and studied. The conclusions are as follows: in order to minimize the generation of Cao in sulfur-containing square tube steel, Omega in molten steel; (O) It must be taken off to 10 & times; The rate of calcium can only be guaranteed below 10-6.
Word of mouth recommendation.Stainless steel q355b square pipe for fluid transportation, Standard No.: gbt12771-1991. The representative materials are 0Cr 0cr19ni 00cr19ni 00cr1 0cr18ni11nb, 0017cr17ni14mo2, etc. It is mainly used to transport low-pressure corrosive media.
General shot blasting is used for square tube with regular shape. Several polishing heads are up, down, left and right, with high efficiency and little pollution.
Performance index analysis of square tube - impact toughness the load acting on the part at a great speed is called impact load, and the ability of metal under impact load is called impact toughness.
After the sample is flattened to the specified flattening distance h, remove the load and remove the sample.
target.Among them, q355b square tube is divided into process & mdash& mdash; Arc welded square pipe, resistance welded square pipe (high frequency and low frequency), gas welded square pipe and furnace welded square pipe are divided by weld & mdash& mdash; Straight seam welded square pipe, spiral welded square pipe.
Improve the positioning and pre bending steps, if necessary, 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.
The 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.
KedzierzynKozle.Hardness test is to determine the hardness of seamless q355b square pipe by slowly pressing a hard indenter on the sample surface according to the specified conditions, and then testing the indentation depth or size.
At present, square tubes also have many good properties, strong corrosion resistance and heat resistance, and are widely used in many scientific and technological fields. Therefore, even so, wise people still do not stop studying the surface adhesion resistance of square tubes. Square tubes in the future will have better performance and make more important contributions to development.
The q355b square tube rolled from the strip steel through process treatment is generally to unpack, flatten, curl and weld the strip steel to form a round tube, then roll the round tube into a square tube, and then cut it to the required length. Nowadays, the forming of q355b square tube has solid bending and empty bending. The bending degree of q355b square tube shall not be greater than 3mm per meter, and the total bending degree shall not be greater than the actual bending of the total length. As the name suggests, the bending is compacted, and the internal and external rollers and the internal and external walls of the tube blank are compacted in both directions during the actual bending.