Perennial Sales Of Various Materials Quality Seamless Steel Tube.

Perennial sales of various materials quality seamless steel tube.

The seamless steel tube has a hollow section, which is used as a pipeline for conveying fluids, such as pipes for oil, gas, gas, water and certain solid materials. Compared to the steel pipe and round steel solid steel bending torsional strength phase at the same time, the weight is lighter, is a kind of economic cross section steel, widely used in the manufacture of structural and mechanical parts, such as petroleum drill pipe, auto transmission shaft, bicycle frame and construction of steel scaffolding is used with steel pipe manufacturing annular parts, such as can improve material utilization, simplifying the manufacturing process, material saving and processing time, has been widely used to make steel pipe.

Seamless steel tubes are widely used. The common use of seamless steel tube consists of ordinary carbon structural steel, low-alloy structural steel or alloy structural steel rolling, with the most output, mainly used as pipeline or structural parts for conveying fluids. 2. Supply according to different USES: a, according to chemical composition and mechanical performance; B. Supply by mechanical performance; C. Supply by water pressure test. Steel tubes supplied by class a and class b shall also be tested for hydraulic pressure. 3. The special purpose of seamless pipe is seamless tube for boiler, seamless steel tube for geological use and seamless pipe for petroleum.

The production process

Main production process of hot rolled seamless steel pipe (main inspection process) :

Tube billet preparation and inspection: tube billet heating, perforation, tube, steel tube reheating, determination (reduction), heat treatment, tube straightening, finishing, testing (nondestructive, physicochemical, bench), and storage.

The main production process of cold rolling (drawing) seamless steel pipe:

Preparation of billet - acid - cleaning - cold rolling (drawing) - heat treatment - straightening - finishing - test.

General seamless steel tube production process can be divided into cold drawing and hot rolled, cold rolled seamless steel tube production process generally more complicated than hot rolled, three-roll rolling tube billet must first, after the extrusion sizing test, if there is no response after crack on the surface of pipe have to be cut after cutting machine, cutting grow about a meter of billet. And then enter the annealing process, annealing with acid pickling liquid, pickling when should pay attention to whether there is a lot of bubble surface, if there is a lot of bubbles show that the quality of the steel tube can not meet the corresponding standards. Appearance on cold rolled seamless steel tube is shorter in hot rolled seamless steel pipe, cold rolled seamless steel tube wall thickness generally smaller than hot rolled seamless steel tube, but the surface looks brighter than the thick wall seamless steel tube, not a lot of rough surface, the diameter is not a lot of burr.

The delivery status of hot rolled seamless steel tube is usually made after heat treatment. Hot-rolled seamless steel tube after qc should pass staff strict manual pick, after the quality inspection for surface coating of oil, and then followed by cold drawing experiment many times, perforation of the experiments conducted after hot rolling processing, if the punched hole diameter is too large for straightening straightening. After straighting, the transmission device is transmitted to the flaw detector for testing. Finally, the label and the specification are placed in the warehouse.

Circular tube billet and heating to punch, three-roll skew rolling, rolling, or pressing - pipe - sizing (or reducing) - cooling - straightening to hydrostatic test or inspection - > tag, warehousing seamless steel tube is made from solid tube ingot or the perforation capillary, then through hot rolling and cold rolling or cold dial. The specification of seamless steel tube is indicated by outer diameter * wall thickness mm.

Generally greater than 32 mm hot rolled seamless steel tube diameter, wall thickness 2.5 200 mm, to 6 mm cold rolled seamless steel tube diameter, wall thickness to 0.25 mm, to 5 mm thin wall pipe diameter thickness less than 0.25 mm, cold than hot rolled high dimensional accuracy.

Generally, the seamless steel tube is made of low alloy steel or 40Cr, 30CrMnSi, 45Mn2, 40MnB, etc., such as 10, 20, 30, 35, 45, etc., such as low alloy steel or 40Cr, 30CrMnSi, 45Mn2, 40MnB, etc. The seamless tubes made of low carbon steel, such as 10 and 20, are mainly used in the fluid transportation pipeline. 45, 40Cr and other medium carbon steel made of seamless pipe to make mechanical parts, such as the mechanical parts of cars and tractors. Generally use seamless steel tube to ensure strength and flattening test. The hot rolled steel tube is delivered in hot rolled state or heat treatment state; Cold rolling is delivered in heat treatment condition.

Hot rolling, as the name implies, the temperature of the rolling piece is high, so the deformation resistance is small and can achieve large deformation. Taking the rolling of steel plate as an example, the thickness of continuous casting billet is about 230mm, and the final thickness is 1~20mm after rough rolling and fine rolling. At the same time, because the thickness of the steel plate is smaller, the dimension precision requirement is relatively low, and the plate shape problem is not easy to appear, so as to control the convexity. For organizations have requirements, usually by controlled rolling of cooling, the control of the finishing rolling temperature and finishing temperature. The circular tube billet - heat - perforation to heading, annealing and pickling to apply oil (copper), multi-channel time cold drawing (cold) and billet tube - heat treatment - straightening to hydrostatic test (NDT) - > tag, put in storage.