Hot Rolled Steel Pipe Surface Drying Processing Condition

Layered in the thickness direction of the steel tension performance deteriorated significantly, and there may be an interlayer tear weld shrinkage. Weld shrinkage-induced local strain reaches the yield point strain often several times larger than the load caused by the strain; implementing computer controlled rolling, after finishing laminar cooling, the machines become straight hair volume straight hair volume of the head, tail and tongue often showed fishtail, thickness, width accuracy is poor, often there is wave-shaped edge, folding, pyramid and other defects. their weight heavier volume, coil inner diameter of 760mm general pipe industry prefer to use after the straight hair volume by cutting head, cut tail, trimming and multi-pass straightening, leveling and other finishing line treatment, and then cutting board or heavy volume, it becomes: hot-rolled steel, hot-rolled steel coil leveling, slitting with other products. hot rolled after finishing roll if descaling by pickling and oiling Serve hot pickling coils.Hot-rolled and cold rolled belong to the process of seamless steel pipe, they have a great impact on the microstructure and properties of steel, rolled steel, hot-rolled mainly based, cold-rolled steel used only for the production of small and thin. Prevent Hot-rolled steel billets produced a burn defects of various kinds of steel over-burning temperatures. For large thermal sensitivity of steel, heating temperature within the allowable range and piercing the lower temperature taken to prevent delamination and the folding defects; must consider the quality of the tube. For example, compression is smaller than the tube, its poor low magnification, a large degree of aggregation of non-metallic inclusions, prone to overheating, the heating temperature and the temperature should be slightly lower than the piercing with steel normal. Similarly, a large phase level 1Cr18Ni9Ti steel billet heating temperature should be slightly lower than normal.Hot-rolled steel in the spray (throwing) radio processing before using cleaning method for removing grease and fouling the pipe surface, using the tube furnace preheated to 40 for a 60 , the surface of the steel pipe to keep dry in the spray (throwing Hot-rolled steel surface) is shot process, the pipe surface without grease and other dirt, rust can enhance the effect of the dry surface of the pipe is also conducive to steel shot, steel grit and separation of rust and scale, rust after that more clean. For hot-rolled steel thickness and edge width not control this. We are familiar with thermal expansion and contraction, since the beginning of the hot rolling out even the length, thickness are standard, and finally cooled or there will be some negative difference, this negative difference edge width wider, thicker the more obvious manifestations. So for large steel for steel edge width, thickness, length, angle, and no law requires sideline too precise.