Seamless steel pipe mill is a rolling mill, comprising: a plurality of outer circumferential surface of the roll or rolls of pipe or tube; core rod-like internal tool and pipe or tube coaxially arranged; the roll and the internal define a deformation zone between the tool roll and internal tools suitable for successively perforated tube and extension tubes.
To improve the joint operation and specified perforations extend at both axial ends in each of the at least one portion of these rollers, which part is configured to bite into a pipe or tube and, arranged in two rolls in the axial between the end of the section is provided in a cylindrical compression straps, internal tool has perforated tube ends in the axial zone and adjacent areas and perforated cylindrical rod section with compression work together to extend the pipe , and a cylindrical section for biting and transport compressed with this arrangement, not only the perforated tube, and the tube extension can be achieved in the roll axis parallel to the axis of the tube or tube axis arrangement to when.
Capillary rolling is the main deformation process in hot-rolled seamless steel pipe production, its role is to make the capillary wall thickness near or at the finished tube wall thickness, and the elimination of vertical thickness of the capillary produced during piercing uneven, the other can improve Shortage of quality inside and outside surfaces of the tube, control tube diameter and roundness shortage. Rolled into a hollow shell close to the finished size of the mother pipe.
1, the automatic rolling machine: automatic rolling machine for two-roll mill Longitudinal irreversible, which is characterized by a pair of high-speed reverse spin echo rolling work roll after roll, the role is to go through a capillary to the foreground rolling second rolling, so its low productivity, most domestic unit has been transformed or eliminated. Roll material is infinitely more chilled cast iron, ductile iron or chilled iron, hardness HSD50 more.
2, two rollers rolling units: rolling unit is more advanced steel mill, which is set after piercing the capillary on a long rod, after more than a rack sequential arrangement and adjacent rack roller seam mutual mistake 90 ° continuous rolling machine rolling. Rolling roll material mostly nickel-chromium-molybdenum unlimited chilled ductile iron (also called pearlite ductile iron), nickel-molybdenum unlimited chilled ductile iron (also known as ductile iron needle), female part hardness HSD50-65. Foreign design of the first aircraft rolling roll and some use of forged steel or graphite materials to further enhance the strength of the vehicles roll.
3, three-roll rolling units: three roller adjustable MPM tube machine (PQF) is an Italian company INNSE to overcome the inherent limitations of the two-roll rolling tube machine and developed, since it bore 360 ° type is divided into three parts, reducing the line speed gap at the bottom of each roll with the edge of the hole, and thus high precision rolled steel.
Small PQF rolling mill rolls are monolithic, nickel-chromium-molybdenum unlimited chilled iron, hardness control HSD55-65 more appropriate time; large PQF rolling mill rolls made assembled, that the use of roll wear Ni-Cr-Mo infinitely better chilled ductile iron, high-strength forged steel shaft materials, and after quenching, can be reused, significant cost savings.
Optimum efficiency control of high frequency welded pipe in welding process
In most cases, optimized welding process, power loss can be reduced 50% and can improve the welding quality, reduce downtime, increase production.
Stress on the trench corrosion of high-frequency straight seam resistance welding pipe
Trench etching is generally believed that acute heat in the welding process, the results of local tissue metal and chemical change caused by quenching.
Technology of straight seam high frequency resistance welded steel pipe
Factors that affect the raw material for the steel pipe welding quality affect the quality of raw materials are mainly steel mechanical properties unstable surface defects and strip geometry deviation big three aspects, therefore, we should focus on these three aspects of control.
