Mechanical Properties and Microstructure Comparative Analysis of 500MPa Hot Rolled H-Section Different Positions for Ultra-Deep well Platform
With the increase of drilling depth, the mechanical properties of H-section steel used in drilling platform are more and more demanding. In this paper, the strength, low temperature impact toughness, plasticity, micro-hardness and microstructure of 500MPa hot rolled H-section steel produced by TMCP process were analyzed, and the strengthening mechanism was also studied. The results show that flanges of TMCP hot rolled H-section steel had the best strength and toughness, while the yield strength at web and R Angle was reduced to 91% and 78% of the flange, respectively. The impact toughness at -40°C of web and R Angle was reduced to 86% and 38% of the flange , and the micro-hardness reduced to 91% and 85% of the flange, respectively. The main strengthening mechanism of the TMCP hot rolled H-section steel is fine-grain strengthening, the carbonitride of V precipitation strengthening and surface bainite transformation strengthening.