Tianjin Yuantai Derun group has 18 wholly-owned subsidiaries, of which Tianjin Yuantai Technology Development Co., Ltd. was founded in 2014 to produce super large diameter and super thick wall rectangular tubes, which are scarce in the market. This kind of non-standard pipe is made of longitudinal submerged arc welded pipe or seamless steel pipe as raw material, and the raw material is extruded twice to form a square rectangular pipe meeting the quality requirements. Moreover, Tianjin Yuantai Technology Development Co., Ltd. can also produce various specifications of special-shaped tubes such as right angle tubes, octagonal tubes and trapezoidal tubes, and undertake tempering and annealing processes.
1、 Production specifications and technical standardsTianjin Yuantai Technology Development Co., Ltd. has 4 production units and more than 50 employees, which undertake large-diameter thick wall rectangular tubes, seamless rectangular tubes, special-shaped tubes, hot-rolled rectangular tubes, square tube specifications of 80 * 80mm-1200 * 1200mm, rectangular tube specifications of 50 * 100mm-1200 * 1500mm, wall thickness of 2.75mm-50 mm, in accordance with the standard GB / t3091-2015, Any specification and material in this range (such as Q235 / q355 / Q390 / Q420 / Q460 / high strength steel / weathering steel, etc.) can be customized. Among them, the outgoing process of hot-rolled right angle pipe is particularly advanced. Two technical methods of on-line hot rolling four corners and overall heating are adopted, which has the advantages of both power saving and high efficiency.
2、 Process flowInspection of round pipe (raw material) – feeding – hydraulic propulsion – roll extrusion (round square change) – Inspection of steel pipe (overall dimension, flatness, perpendicularity and R angle) – blanking (inspection of steel pipe straightness and twist) – shaping of mouth end (there will be deformation area at the head end during steel pipe deformation) – sawing and trimming – Inspection and spraying standard – Warehousing
3、 Processing businessThe main purpose of the new intelligent tempering furnace equipment of Tianjin yuantaiderun group is to remove the internal stress in the steel pipe. The methods of removing internal stress include natural aging and artificial aging. Natural aging is that the steel pipe is placed in the open field for more than half a year, and it will form slowly, so as to eliminate or reduce the residual stress. There are two methods of artificial prescription:① Heat treatment to remove internal stress: heat the steel pipe to 550 ~ 650 ℃ for stress relief annealing, which saves time than natural aging and removes residual stress more thoroughly② Vibration stress relief: in short, it is to eliminate the stress of steel pipe by vibration. VSR is to apply additional alternating stress or deformation to the workpiece by using the resonance of the workpiece. When the additional alternating stress is superimposed with the residual stress and absorbs energy through the internal friction of the material to reach or exceed a certain threshold value of the material, the workpiece will undergo micro or macro viscoelastic plastic mechanical deformation, so as to reduce and homogenize the residual stress in the workpiece and stabilize its dimensional accuracy.The square rectangular tube after internal stress relief annealing ensures the mechanical properties, especially in the aspects of yield strength, tensile strength, elongation and impact compressive capacity, and realizes the effect of 1 + 1 > 2.
4、 Engineering performance1. The main column of the 128M Ferris wheel of Shenzhen OCT adopts the inclined octagonal tube produced by Yuantai technology
2. The construction of Google tower in Singapore adopts 500mm * 500mm * 36mm modified pipe produced by Yuantai technology, made of s355j2h, with a total of 4000 tons
3. For the establishment of Sichuan Tianfu airport, 90mm * 250mm * 20MM modified pipe produced by Yuantai technology is adopted
4.The headquarters of Beijing Chaoyang aiib was established by adopting 500mm * 520mm * 22mm modified pipe produced by Yuantai technology
5. National Convention and Exhibition Center (Tianjin) venueAt the “China Building Science Conference and green smart building Expo”, the first exhibition of the National Convention and Exhibition Center (Tianjin) held on June 24, 2021, Tianjin yuantaiderun group provided square tube (200) for the construction of the national exhibition × seven hundred × 8mm，200 × seven hundred × 10mm，200 × seven hundred × 12mm，200 × seven hundred × 16mm，200 × eight hundred × 8mm，200 × eight hundred × 10mm，200 × eight hundred × 12mm，200 × eight hundred × 16mm) is mainly used for column structure and supporting structure. The umbrella shaped steel structure of the main body of the main entrance landing Hall of the exhibition hall is made of “yuantaiderun” brand structural steel pipe products.