一种超级铁素体不锈钢的平衡相图及晶粒长大行为研究

INVESTIGATION ON THE PHASE DIAGRAMAND GRAIN GROWTH BEHAVIOR OF A SUPER FERRITIC STAINLESS STEEL

超级铁素体不锈钢因具有优异的化学性能、物理性能和加工性能,广泛应用于建筑、能源和化工领域。选用0. 008C-29Cr-2. 5Mo超级铁素体不锈钢,用Thermo-Calc软件计算其相图,在1 100℃和1 200℃分别等温1 min、2 min、5 min和10 min观察试验钢晶粒长大的规律。试验主要结果为:试验钢的液相线1 521℃;单相铁素体区的温度范围825～1 506℃,775℃以下出现σ相;试样钢在1 100℃和1 200℃保温1～10 min范围内,晶粒尺寸与保温时间基本呈线性关系。上述关系式分别为:1 100℃时,D=267+19t;1 200℃时,D=372+51t。

Super ferritic stainless steel has excellent chemical, physical, and processing properties, which is widely used in construction, energy, and chemical industries. In this paper, 0.008C-29Cr-2.5Mo steel was selected as a model material, the phase diagram was calculated by Thermo-Calc program; the law of grain growth was observed at 1 100 ℃and 1 200 ℃respectively of isothermal 1 min, 2 min, 5 min and 10 min . The main results are as follows： the liquidus of the test steel is 1 521 ℃; the temperature range of single phase ferrite is 825~1 506 ℃ and phase appears below 775 ℃; the grain size is basically linear with the holding time in the range of 1 100 ℃ and 1 200 ℃ for 1~10 min. Their relationship equations are： D =267＋19 t at 1 100 ℃ and D =372＋51 t at 1 200 ℃, respectively.