Corrosion in the form of seamless steel pipe for buried pipelines are divided into two kinds of localized corrosion and uniform corrosion, localized corrosion mostly dominated, the danger is also the largest.

Surface hardening, heat treatment commonly used induction heating or flame heating manner. The main technical parameters of surface hardness, hardness and effective local hardened layer depth. Hardness testing Vickers hardness tester can also be used or Rockwell Superficial Rockwell hardness. Test Force (ruler) of choice and effective case depth and hardness of the surface. This involves three kinds of hardness.

Process principles for steel pipe factory electroplating wastewater treatment: electroplating wastewater from the electroplating process plating, the bath filtration, waste bath emissions.

Steel tube cutting machine includes laser cutting machine, square tube laser cutting machine, oval tube laser cutting machine. The pipe cutting machine processing has a wide range to meet the user pipe cutting and processing, square pipe, oval shape pipe.

Welded steel pipe (ERW steel pipe, LSAW steel pipe, SSAW steel pipe )is made of teel plate or strip after the basic curl after molding .Welded steel pipe manufacturing process is simple, efficient, and more varieties of different specifications, equipment, less capital, but the general strength of less than seamless.

Anti-corrosion steel in people's daily life and plays an important role in different, anti-corrosion steel pipe generally refers to using a special process for ordinary steel pipe anti-corrosion treatment, the steel pipe has some corrosion resistance in general, or for the waterproof, rust-proof, anti-acid, oxidation and other characteristics, the general said PE anti-corrosion steel refers to polyethylene pipe corrosion, is the use of advanced science and technology from the processing of the article, PE anti-corrosion steel is widely used in petroleum, natural gas, city gas, city water, coal slurry transportation pipeline and so on.

As there is no need to add filler metal during the welding process of HFW steel pipe, it has the advantage of high welding speed and high production efficiency, and it is widely used in oil and gas transport, oil pipelines, structures and various mechanical pipe and other fields.

Mild carbon steel pipe annealing organization ferrite and a small amount of pearlite, lower its strength and hardness, good ductility and toughness.

Steel pipe delivery status(condition): cold / hard (BK), cold / soft (BKW), after cold stress relief annealing (BKS), annealing (GBK), normalized (NBK).

Modern straight seam submerged arc welding steel pipe (UOE, JCOE) in the manufacturing process have set up continuous welding process. Its role is carried out after forming the tube shape, forming the inner weld seam position and back in order to ensure that the steel pipe size and shape for pipe welding, welded pipe quality and production efficiency is increased.

There are usually two heating products for the pipe billet of the welded steel pipe, including pre-heating and rolling tube. When manufacturing welded steel pipe, the two heating products should be heated before in a given path, and it requires the use of intermediate annealing so that the residual stress can be removed.

The helix angle of the spiral welded pipe is generally 50-75 degrees, the synthesis of spiral weld stress is longitudinally welded pipes of 60-85% of the principal stress. In the same work under pressure, spiral welded pipe of the same diameter than the straight seam welded pipe wall thickness can be reduced.