Papers by Keyword: Low Carbon Bainite Steel

Abstract: The corrosion behaviors of a low carbon bainite steel in three atmosphere environments simulated by corresponding solutions were investigated in this accelerated test. It is found that the corrosion rate of the low carbon bainite steel is lower than that of the commercial weathering steel 09CuPCrNi in all the three solutions. The corrosion rates of the bainite steel in the three solutions are also different, which is most serious in the solution containing both chloride and sulfide. There is no serious selective corrosion, for the corrosion has little effect on the mechanical property of the bainite steel. Corrosion rates are relation to the amount of Cu and Cr enrichment in rust layers, which are well corresponding to the specific surface area values of corrosion products. Inhibit effect can be found in the solution containing both chloride and sulfide.

Abstract: The dominant microstructures in low carbon bainite steels such as bainitic ferrite are non-equilibrium phases, which will tend to evolve into equilibrium phases when the steels are subjected to thermal disturbance. In-situ observation by optical and scanning electron microscopy was carried out in this investigation to track the evolution when the steels were isothermally held below A1 temperature. It is found that the primary polygonal ferrite grows slowly during isothermal holding, while bainitic ferrite changes rapidly into polygonal ferrite. Self-tempered bainitic ferrite would recover further and recrystallize. The lower the concentration product of carbon and niobium, the faster is the evolution.

Abstract: Statistical analysis was carried on weld defects of low carbon bainite ADB610 steel using shielded metal arc welding (SMAW) and mixed active-gas arc welding (MAG). By Pareto diagram analysis, although the ratio of porosity air hole using SMAW is slightly higher than the one using MAG, there is no qualitative difference in ADB610 steel weld defect types between two welding methods. And the crack occurs seldom, which indicates ADB610 steel has lower crack-sensitivity using SMAW and MAG. By histogram analysis and rank test, it can be concluded that there is distinctive difference in defect size between SMAW and MAG, and the average size using SMAW is bigger than the one using MAG. So if possible, MAG is recommended for low carbon bainite ADB610 steel.