42CrMo seamless steel pipe is an ultra-high-strength steel with high strength and toughness, and good hardenability.

Q345C rectangular tube has the ability to resist atmospheric oxidation, and also has the ability to resist corrosion in the medium containing acid, alkali and salt; but the size of its anti-corrosion ability depends on the chemical composition of the steel itself, the mutual state, and the conditions of use. and environmental media type.

The most common defect of stainless steel welded pipe is the uneven wall thickness of the pipe.The eccentricity of the wall thickness of the stainless steel welded pipe will bring a series of adverse effects on the strength of the steel pipe and further cold working, thus affecting the economic benefits. When rolling large-diameter thick-walled stainless steel pipes, the local reduction increases, causing cracks and mechanical failure of the rolling mill.

Hollow section annealing can maintain bright appearance and dimensional accuracy, and annealing of cold-rolled strips with no surface oxidation and no decarburization in a protective atmosphere.

Brittle fracture is caused by a variety of reasons. For example, when there are precipitates on the grain boundary, no matter their strength is stronger or weaker than that of the matrix, it is the cause of cracks; the segregation of inclusions on the grain boundary is also the cause of fracture; in addition, even at the intersection far less than the yield limit Under the action of variable load, fatigue fracture will also occur. During the low-stress brittle fracture that occurs in high-strength metallic materials, the material structure is far from homogeneous and isotropic.

The cracking of stainless steel flanges is due to the presence of a large number of non-metallic inclusions in the forging billets used to make the flanges during the forging process, and the volumetric inclusions are repeatedly forged into regional inclusions, resulting in forging cracks along the tip of the inclusions in the material, forging After forging, the larger inclusions turn into larger cracks, and the smaller inclusions turn into smaller microcracks after forging.

High-frequency quenching requires that the matrix is mainly pearlite after normalizing, and it is cooled by water spray or polyvinyl alcohol solution; the tempering temperature is 200-400 ℃, and the hardness is 40-50HRC, which can ensure the hardness and wear resistance of the surface of the square tube.

We all know that the welding process of ssaw steel pipe is a more critical aspect in the process of processing and production. Only after strictly controlling the craftsmanship can we ensure that the overall surface workmanship will be better, and achieve the trust and recognition of customers in the process of sales. Therefore, what problems should be paid attention to in the welding process?