Why does the seamless steel pipe with small diameter and thick wall produce transverse cracks?

Why does the seamless steel pipe with small diameter thick wall tube produce transverse cracks?

During the use of seamless steel pipe with small diameter thick wall tube, the surface sometimes encounters the phenomenon of transverse cracks. There are many reasons for such a situation. Let me make a detailed analysis for the application scope of seamless steel pipe with small diameter thick wall tube. If the deformation of seamless steel pipe with small diameter thick wall tube is relatively small under the condition of air drawing, the inner and outer surfaces of seamless steel pipe will produce additional stress field of internal pulling.

At this time, due to the difference in deformation and wetting, the expansion trend of the outer surface is greater than that of the inner layer, and the seamless steel pipe produces additional tensile stress on the inner and outer surfaces. If the additional tensile stress of the inner and outer surfaces is very large, the basic stress field and the additional stress field during drawing are added together, and the seamless steel pipe is upgraded for centralized incineration treatment system management.

Small-diameter thick-walled seamless steel pipes eliminate the negative leakage that cannot exceed the nominal diameter thickness in depth, which causes the inner layer of the seamless steel pipe to cause transverse cracks.

Under the corresponding theoretical mechanical conditions, various factors that reduce the plastic deformation during the production and processing of seamless pipes will increase the chance of internal transverse cracks. Therefore, when manufacturing small-diameter thick-walled seamless steel pipes, heat treatment quality and elimination of alkali embrittlement are very important. In the case of air drawing, in addition to the additional stress field in the axial direction, there is also an additional stress field in the axial direction. The longitudinal crack is caused by the additional axial tensile stress caused by air drawing.

Study on the continuous high-temperature corrosion of small-diameter thick-walled seamless steel pipes. According to the worrying continuous high-temperature corrosion caused by the conversion of the heating furnace to long flame coal with a high sulfur content. The main reasons for the corrosion of the superheater tube under high temperature are analyzed, and the corrosion of the corrosion principle of continuous high-temperature sulfur corrosion and continuous high-temperature chlorine corrosion in a relatively high oxidizing atmosphere is analyzed. Combined with the implementation of the practice of pine wood particles in Datong City with low sulfur content in Yangquan coal, the centralized incineration system management is upgraded.

The depth of the small-diameter thick-walled seamless steel pipe cannot exceed the negative leakage of the nominal diameter thickness, and the thickness of the practice at the elimination point cannot be less than the minimum value agreed by the thickness. There are various ways to prevent the heating furnace from heating up quickly in an accident and causing deformation and collapse. It is important to adopt different methods according to different situations, such as using insulation and refractory insulation materials to block the flame from burning the steel frame immediately, reduce the speed of the heat transfer process, delay the temperature rise of the steel frame, and the time for the tensile strength to weaken. But no matter what method is used, the basic concept is the same. Flame retardant materials are a relatively good fire safety professional method in recent years.