SSAW Pipe

For welded tubes of special materials, heat treatment must be carried out before and after welding, which is very important to the welding quality. The pre-heating of welded pipes made of special materials can not only slow down the cooling rate after welding, but also help hydrogen diffuse and escape from the weld metal to avoid hydrogen-induced cracking. At the same time, the degree of hardening of the weld seam and the heat-affected zone is reduced, and the crack resistance of the welded joint is improved. It can also reduce the welding stress, uniform local or overall preheating, and reduce the temperature difference between the weldments in the welding area, so that on the one hand, the welding stress is reduced, and on the other hand, the welding strain rate is reduced, which is beneficial to avoid welding cracks. It can reduce the degree of restraint of the welded structure, especially for reducing the degree of restraint of the fillet joints. As the preheating temperature incre...

 What is welding slag inclusion? Welded pipe slag inclusions are slag that remains inside the weld. Welding slag inclusions are generally divided into two categories: The first category is metal slag inclusions. The second category is non-metallic slag, which refers to the slag remaining in the weld after welding, including electrode coating or flux, sulfide, oxide and nitride. According to its formation, it can be divided into point-like slag inclusions, linear slag inclusions, chain-like slag inclusions and dense slag inclusions. Slag inclusions will reduce the plasticity and toughness of steel pipe welds, and slag inclusions with sharp corners will cause stress concentration at the tip, and the tip will develop into a crack source, especially in welds with a large tendency to air quenching. Under the action of stress on the steel pipe, cracks will first appear at the slag inclusions in the weld and develop along the way, resulting in a decrease in strength and cracking of the we...

What is welding slag inclusion? Welded pipe slag inclusions are slag that remains inside the weld. Welding slag inclusions are generally divided into two categories: The first category is metal slag inclusions. The second category is non-metallic slag, which refers to the slag remaining in the weld after welding, including electrode coating or flux, sulfide, oxide and nitride. According to its formation, it can be divided into point-like slag inclusions, linear slag inclusions, chain-like slag inclusions and dense slag inclusions. Slag inclusions will reduce the plasticity and toughness of steel pipe welds, and slag inclusions with sharp corners will cause stress concentration at the tip, and the tip will develop into a crack source, especially in welds with a large tendency to air quenching. Under the action of stress on the steel pipe, cracks will first appear at the slag inclusions in the weld and develop along the way, resulting in a decrease in strength and cracking of the weld. T...

The production of seamless tubes requires cold drawing technology, so some defects may appear during the cold drawing process. What are the specific reasons for the defects in seamless tubes during cold drawing? Next follow the seamless tube manufacturers to find out. What is a cold drawn seamless tube? Cold-drawn or cold-rolled precision seamless tubes are cold-drawn or cold-rolled precision seamless steel tubes with high dimensional accuracy and good surface finish for mechanical structures and hydraulic equipment. Cold drawn seamless tube production process: Round tube blank →heating →piercing →head →annealing →pickling →oiling (copper plating) →multi-pass cold drawing (cold rolling) →blank tube →heat treatment →straightening →water Pressure test (flaw detection) →marking →storage. The root cause of defects in the production process cold drawn seamless tubes: 1. The quality of the cold drawn seamless tube material and the middle pipe is not good enough, and the geometrical specifica...

After entering the 21st century, on the one hand, the refractory industry continues to deepen and vigorously promote the scientific and technological achievements obtained during the "Eighth Five-Year Plan" and "Ninth Five-Year Plan"; Supported by other scientific and technological projects, we have continued to develop and apply a number of new technologies and products with independent property rights; at the same time, the Refractory Branch of the Chinese Society of Metals and the National Refractory Standardization Technical Committee have played an important role in promoting industry academic exchanges and industry standardization work. . Refractory professional higher education and corporate R&D centers continue to develop, and the scientific and technological innovation capabilities continue to increase. The level of large-scale production equipment, automation, and intelligence has been continuously improved, and the quality of industry operation and th...

 What is Structural Seamless Steel Tube? a. Structural seamless steel tubes are seamless tubes used for general structures and mechanical structures, and the main materials are carbon steel and alloy steel. b. Structural stainless steel seamless tubes are hot-rolled (extruded, expanded) and cold-drawn (rolled) stainless steel pipes and structural parts and parts widely used in chemical, petroleum, textile, medical, food, machinery and other industries. ) seamless steel tube. From the perspective of mechanism, it is generally believed that non-metallic inclusions in the tube blank will destroy the continuity and compactness of the 16mn structural seamless steel tube, and serious inclusions may even cause delamination inside the 16mn structural seamless steel tube. The other is considered to be hydrogen-induced cracking, that is, due to the accumulation of hydrogen in the steel, the partial pressure of the gas inside the metal is too high, white spots are formed in the round tube bil...