【摘要】 利用共焦激光扫描显微镜原位观察了AISI304不锈钢冷却过程中高温铁素体(δ)→奥氏体(→)相变的过程及其特征．结果表明,γ相优先在δ晶界处形成；冷却速率影响γ相的生长形态,典型形态分为块状、圆形、树枝状等；“游离”γ枝晶发生粗化,并和周围的γ枝晶聚合；相同冷却条件下,δ晶界处的γ枝晶聚合程度明显高于δ晶粒内部；二次枝晶在冷却过程中粗化,并竞争生长．利用ThermoCalc计算C元素在δ→γ相变过程中的偏析系数,以此求解δ→γ相变数学模型．更多还原

【Abstract】 The process and characteristics of high-temperature ferrite (δ)→austenite (γ) trans- formation during cooling of the stainless steel AIS1304 have been observed in sitar by using a confocal laser scanning microscope.The results show that theγphase appeared prior at theδgrain bound- aries;The cooling rate affects the growth morphology ofγphase which includes block-like,round,and dendritic;The independentγdendrite becomes coarse,and may also aggregate with surroundingγdendrites,the aggregate degree atδgrain boundary is obviously higher than that within the grain at the same cooling rate;The secondary dendrites became coarse,and grew competitively during cooling. Based on the calculated partition ratio of C duringδ→γtransformation by using ThermoCalc,the mathematical model ofδ→γtransformation is solved.更多还原