During the rolling process of seamless steel pipes, due to the influence of the stability of the machine and peripheral equipment and the uncertainty factors in the production process, the product dimensions often exceed the tolerance range specified in the product standard. The situations are as follows:

Grinding of thick-walled seamless nozzle: After cutting, use an angle grinder to grind the plastic layer of the nozzle. Its purpose is to prevent the plastic layer from melting or even burning during the flange welding process, damaging the pipe, and grinding the nozzle plastic layer with an angle grinder.

A flange is a disc-shaped part that is most common in plumbing engineering.It is the part that connects the pipes to the pipes. Connect to the pipe end. There are holes on the flanges for bolts to connect the two flanges tightly. The flanges are sealed with gaskets.

The medium used for quenching and cooling of seamless steel pipes is called quenching cooling medium (or quenching medium). The ideal quenching medium should have the condition that the steel can be quenched into martensite without causing too much quenching stress.The commonly used quenching media for quenching and cooling of seamless pipes are water, aqueous solution, mineral oil, molten salt, molten alkali, etc.

Submerged arc welding is an important welding method. Its inherent advantages of stable welding quality, high welding productivity, no arc and little smoke make it an important steel structure in the production of pressure vessels, pipe sections, box beams and columns. the main welding method.

Hydrogen embrittlement is usually manifested as a significant decrease in the plasticity of steel, a sharp increase in brittleness, and a tendency to rupture after a period of time under static load (often lower than the σb of the material).