Shenzhen straight seam steel pipe factory | hot rolling of large-diameter straight seam steel pipe plant | thick-walled steel pipe plant | Dongtai Steel Pipe Co., Ltd. in Cangzhou City manager left Yu Peng: 18730700585 13333272002 North China specializing in the production and sale of steel pipes and pipe fittings one of the large-scale enterprises, Yanshan County, Hebei Province Industrial Park is located in the pipeline equipment production base. East of Huanghua Port, north of Beijing, Tianjin, State Road 205, State Road 104, Beijing-Shanghai Railway cross transit, domestic transportation is very convenient; addition is only 200 kilometers away from Tianjin Xingang, to provide a more convenient conditions for the export business. The company covers an area of ??130 acres, 270 million yuan in fixed assets, the company has advanced production equipment and complete detection means. Now has eddy current flaw detector, ultrasonic flaw detector, nondestructive testing equipment, as well as hydrostatic testing machine WE-600 universal testing machine, WE-1000A hydraulic universal testing machine, as well as a full set of metallographic test equipment and physical chemistry instruments. The company has strong technical expertise, service capabilities and market competitiveness. The right to import and export company in 2008, based on the domestic market and exported to Europe, America and Southeast Asia, Africa and other places, and to establish long-term strategic partnership of cooperation with internationally renowned enterprises, praised by customers. The company adhere to the "integrity of management, quality marketing, and strive to win-win" concept of market operation, the right business ideas, the company has brought good economic returns, and laid a good foundation for network marketing. Production straight seam steel pipe production process can be divided into high-frequency straight seam steel pipes and submerged arc welding straight seam steel pipe. Submerged arc welding straight seam steel pipes are divided into their different ways of forming UOE, RBE, JCOE steel pipe. Here are the most common high-frequency straight seam steel pipes and submerged arc welding straight seam steel pipe forming process. Hot rolling is relative to the terms of the cold-rolled, cold-rolled in the recrystallization temperature below the rolling, and the hot rolling is carried out at above the recrystallization temperature rolling. Advantages can destroy the cast structure of the steel ingot, and the refinement of crystal grains of the steel, and eliminate the defects of the microstructure, so that the the steel organization compacting, improve the mechanical properties. This improvement is reflected in the rolling direction, so that the steel is no longer to a certain extent isotropic; pouring the formation of bubbles, cracks, and osteoporosis, under high temperature and pressure can also be welded together. Disadvantages 1. After the hot rolled steel inside the non-metallic inclusions (mainly of sulphides and oxides, as well as silicates) is pressed into a sheet, stratified (laminated) phenomenon appears. The layering of the steel in the thickness direction by the pull performance deteriorated significantly, and may appear in the weld shrinkage interlayer tear. The local strain induced by weld shrinkage frequently reach several times the yield point strain, the strain is much greater than the load caused; 2. Residual stress caused by uneven cooling. The residual stress is the stress of internal self-phase equilibrium in the absence of external force, the hot-rolled steel of various cross-sectional has a residual stress such Usually steel sectional dimension is the greater, the greater the residual stresses. Residual stress is self-phase equilibrium, but the steel members in the performance external force or have a certain influence. Such as deformation, stability, anti-fatigue