- The cleaning of straight seam steel pipes uses solvents and emulsions to clean the steel surface to remove oil, grease, dust, lubricants and similar organic matter, but it cannot remove the rust, oxide scale, flux, etc. on the steel surface. It can only be used for anti-corrosion production Auxiliary means.
- Straight seam steel pipe rust removal tools mainly use wire brushes and other tools to grind the steel surface, which can remove loose or raised oxide scale, rust, welding slag, etc., manual rust removal can reach SA2 level, power tool rust removal It can reach SA3 level. If the steel surface is firmly attached to the iron oxide scale, the rust removal effect is not ideal, and it cannot meet the requirements of anti-corrosion construction for the depth of anchor particles.
- The pickling of straight seam steel pipes is generally treated by chemical and electrolytic methods. Pipeline anticorrosion can only be treated by chemical pickling, which can remove oxide scale, rust and old coatings, and sometimes can be used as a reprocessing after sandblasting and rust removal. , Although chemical cleaning can make the surface clean and rough to a certain degree, its anchoring particles are shallow and easily pollute the environment.
Tips: ASTM A53B erw steel pipe is a typical carbon steel pipe. It is largely used to convey fluids at low / medium pressures such as oil, gas, steam, water, air and also for mechanical applications.
The method of preventing and reducing welding deformation needs to consider the welding process design to overcome the changes in the heat and cold cycle during the welding process.
Excessive welding metal will not increase the strength, but will increase the shrinkage force and welding deformation.2.
Reduce the weld beadWelding with thick wire and few beads has less deformation than thin wire and multi-bead welding.
When there are multiple beads, the cumulative shrinkage caused by each bead increases the total shrinkage of the weld, and the welding process with less bead and thick electrode is more The welding process effect of welding bead and fine welding rod is better.
The preset amount of anti-deformation needs to be determined by experiment.
Pre-bending, pre-setting or pre-arch welding parts are a kind of reverse A simple method for mechanical force to offset the welding stress.
Outer diameter toleranceERW steel pipe: It is cold-formed, and the sizing is completed by 0.6% reduction.
The process temperature is basically constant at room temperature, so the outer diameter control is accurate and the fluctuation range is small, which is helpful to eliminate black leather buckles;Seamless steel pipe: hot-rolled forming process is adopted, and its sizing is completed at about 8000C.
Wall thickness toleranceERW steel pipe: using hot-rolled coil as raw material, modern hot-rolling thickness tolerance can be controlled within 0.05mm, while seamless steel pipe is produced by round steel perforation method, the wall thickness deviation is large, and the subsequent hot rolling can partially eliminate the wall Thickness unevenness, but the most advanced unit can only be controlled within +5~10%t, which corresponds to 8.94mm thick steel pipe.Seamless steel pipe: The limit of wall thickness control accuracy is 0.9mm.4.
OvalityERW steel pipe: adopts cold bending forming, so the outer diameter control is accurate and the fluctuation range is small.Seamless steel pipe: Hot-rolled forming process is adopted.
Tensile testThe tensile properties of seamless steel pipes and ERW steel pipes conform to API standards, but the strength of seamless steel pipes is generally at the upper limit and the plasticity is at the lower limit.
In comparison, the strength index of ERW steel pipes is in the best state, and the plasticity index is 33.3% higher than the standard.
