High-intensity hydraulic support pipe with wall thickness of 60mm-70mm

Abstract

The invention discloses a high-intensity hydraulic support pipe wall thickness of 60mm-70mm, which includes the components with mixture ratios as follows: C: 0.19-0.32 percent, Si: 0.2-0.8 percent, Mn:1.1-2.1 percent, Ti: 0.001-0.032 percent, V: 0.02-0.16 percent, B: 0.0001-0.0038 percent and the balance of Fe. The hydraulic support pipe after quenched has mechanical performances for the central section as follows: yield strength between 850-1110MPa, tensile strength between 980-1210MPa, longitudinal impact between 39-110 joule, and lateral impact between 33-90 joule; and metallurgical structure after modulation is tempered sorbite and weld crack has sensitivity coefficient that Pcm is equal to 0.356-0.379. The method has the advantages that the technique of the hydraulic support pipe adopts the mode of introduction of element B and element Mn, and quenched depth after elements B and Mn introduced is apparently enhanced, thus ensuring the final strength performance. V and Ti are grain refining elements that can effectively decrease the cold crack trend in weld metal. The precipitation of V and Ti elements plays an active role in inhibiting the growth of grain in heat affected zone, thus improving welding quality.

Description

technical field [0001] The invention belongs to the manufacturing technology of seamless steel pipes for the oil and gas industry in the metal material industry, and in particular relates to a high-strength hydraulic support pipe with a wall thickness of 60mm-70mm. Background technique [0002] Due to the severe situation of global oil supply, the exploration and construction of ultra-deep oil and gas wells has become a major basic project related to the long-term stable and sustainable development of the oil and gas industry. Ultra-high-strength and high-toughness OCTG, as an important industrial material for deep and ultra-deep well construction in the oil drilling industry, has become a hot spot in the research and development of materials at home and abroad in recent years. Due to the high temperature and high pressure environment downhole, ultra-deep wells have special requirements for the strength, toughness, sealing performance, crack growth resistance, bending resist...

AI Technical Summary

Problems solved by technology

When the traditional 27SiMn produces large-thickness hydraulic cylinders, the hardening depth is not enough, which in turn affects the mechanical strength after modulation, burying hidden dangers for safe production. Second, the weldability of large-thickness 27SiMn cannot meet the use requirements of high-strength hydraulic props , the production process of the bracket is high, which increases the production cost