Corrosion resistance of welded steel pipe

　　The corrosion resistance of welded steel pipe with Ni is strong in acid environment. In the environment containing sulfuric acid or hydrochloric acid, the higher the content of Ni, the stronger the corrosion resistance. In general environment, corrosion can be prevented by adding CR to welded steel pipe. The poor edge condition of steel strip is another important reason for wrong edge. The effects of mass flow rate, heat flux and structural parameters on the heat transfer coefficient of saturated bubble boiling in vertical helical tubes are investigated.

　　In the production of welded steel pipe, there are many factors affecting the misalignment. In production practice, the steel pipe is often degraded due to the over tolerance of dry and wrong sides. Therefore, it is necessary to analyze the causes and preventive measures of spiral steel pipe misalignment.

　　Due to the poor shape and dimensional accuracy of the head and tail of the non trimming steel strip, it is easy to cause the steel strip to bend hard and cause wrong edge when butt joint.