Liaocheng virtues Steel Plant (Liaocheng virtue Pipe Co., Ltd.), specializing in the production of seamless pipe, producing an outer diameter of 33-325 Material 20 # 45 # 16Mn seamless, with export rights, has passed API certification, and our agents Baotou Steel pipe, seamless steel pipe outside diameter to 426, the wall thickness to 40. Perennial keep 60,000 tons of stock, please obtain stock tables or to visit our factory. The company shipped with the material book, signed formal contracts, according to GB receipt. Three certificates are available for review. 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, 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, with layer silicate cotton insulation, insulation thickness 50mm gb3087 thick-walled seamless steel pipe, temperature control DJK-A-type electric heater automatic temperature control device. From the tensile test results, tensile specimens broken in two programs of all base metal thick-walled seamless steel pipe, indicating higher than the tensile strength of the weld base metal; bending test all qualified weld plastic is better explained . According to Table 5 toughness test results, impact toughness program Ⅰ Ⅱ 15crmo program was significantly higher than the thick-walled seamless steel tubes, welded proof scheme Ⅰ after heat treatment specifications ideal, tempering not only met the joint organization and performance improvements purpose, and the toughness and strength with appropriate. From room temperature mechanical properties of results, the recommended two welding technology program can be used on-site construction. Ⅰ program used with the base metal composition close to the electrodes, weld properties matching with base metal, weld should have a high heat resistance, welds at high temperatures is not easy to destroy long-term use. PWHT difficulty is more stringent specifications, tempering temperature and time, and heating and cooling rate control properly it will cause the weld performance. Ⅱ program using austenitic stainless steel welding rod, eliminates the need for post-weld heat treatment despite, but because of the weld and base metal expansion coefficient, diffusion of carbon migration phenomenon can occur when a long-term high-temperature operation, easily lead to weld fusion zone damage occurred. Therefore, consider the use of reliability, on-site use of the program Ⅰ welding is more secure. Thick-walled seamless steel pipe industry virtues (certified), thick-walled seamless steel pipe industry by virtue of Liaocheng Limited. 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.