14. Cold-drawn or cold rolled precision seamless steel (GB3639-2000) is a high dimensional accuracy for the mechanical structure, hydraulic equipment and good surface finish drawn or cold rolled precision seamless steel tubes. Use precision seamless steel pipe manufacturing mechanical structure or hydraulic equipment, can greatly reduce machining time, improve material utilization, and help to improve the quality of products. 15. The structure of stainless steel seamless pipe (GB / T14975-2002) is widely used for hot-rolled chemical, petroleum, textile, medical, food, machinery and other industrial corrosion resistant pipes and structural parts and components made of stainless steel ( extrusion, expansion) and cold drawn (rolled) seamless steel pipe. 16. The fluid transport stainless steel seamless pipe (GB / T14976-2002) is used for the transmission fluid hot-rolled stainless steel (extrusion, expansion) and cold drawn (rolled) seamless steel pipe. Welding preparation specimens using 15CrMoG seamless steel pipe, welding specifications for φ325 × 25 with angle grinder before the polish to the exposed metallic luster q345d inside and outside the pipe plant and groove edge bevel 50mm range, and then washed with acetone clean. Specimens fixed horizontal position, counterparts gap 4mm, using GTAW circumferentially uniform spot-six, at the point of each solid length should not be less than 20mm. Welding Table 2 baking specification. 2.3 before welding welding parameters need to be selected as the preheating temperature of 150 ℃. Using oxygen - acetylene flame for heating the specimen, first with temperature pen roughly determine the temperature of the specimen surface (in handwriting to estimate the speed of the color change), the last point temperature was measured with a semiconductor, the measuring point must select at least three Welding, the first layer of GTAW base, in order to avoid the back of the weld seam at Yang dented pipe plant, using time-filler wire method wire, that wire is fed through a gap from the inner tube counterparts. The remaining layers using SMAW total weld 6 layers, each layer of a weld bead. When connected, the interlayer temperature should not be less than 150 ℃, to prevent the interruption caused by the cooling weld test specimen shall be operated alternately two welders welding, slow cooling insulation measures should be taken immediately after welding. Program Ⅰ weld heat treatment using 2.4 weld specimens should be carried out in local temperature tempering after welding. Heat treatment process: heating rate of 200 ℃ / h seamless steel pipe manufacturers, rose to 715 ℃ temperature for 1 hour and 15 minutes, the cooling rate of 100 ℃ / h, down to 300 ℃ for air cooling. Specific use of JL-4 type crawler-type electric heater (1146 × 310) surrounding the weld 20 Seamless Steel Tube Plant, with a layer of silicate cotton insulation, insulation thickness 50mm, temperature control DJK-A type electric heater automatically temperature controller. 20 # seamless steel pipe plant | virtues of Industry (certified) | Zibo Liaocheng Seamless Steel Tube Co., Ltd. is provided by virtue of Industry. Liaocheng virtue Pipe Co., Ltd. (www.meidegc.com) (www.meidegc.com) (www.mdwfg.com) (www.mdggc.com) Shandong Liaocheng, steel leader, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. Industry leaders in the United States and Germany with the staff warmly welcome all inquiries negotiations to create the virtues pipe industry a better future.