CAJ | 학술논문

研究了奥氏体化温度对调质Ti-V微合金钢力学性能的影响。金相和透射电镜观察揭示了奥氏体晶粒尺寸随奥氏体化温度的变化规律。在850~1200℃的温度范围内，随着奥氏体化温度的升高，奥氏体晶粒尺寸经历了稳定-骤增-稳定三个阶段。抗拉强度和冲击韧性试验结果显示，实验钢的抗拉强度Rm随着奥氏体化温度的升高逐渐增加，而冲击韧性则经历了稳定-降低-升高的过程。一定温度下沉淀相粒子的粗化导致了奥氏体晶粒尺寸的突然增加；随温度升高，合金元素不断固溶所导致的回火后弥散析出的增多和沉淀相粒子的有效钉扎是抗拉强度增加的主要原因，而一定温度下晶粒的不正常长大和尺寸均匀化则是影响实验钢冲击韧性的关键因素。
연구료오씨체화온도대조질Ti-V미합금강역학성능적영향。금상화투사전경관찰게시료오씨체정립척촌수오씨체화온도적변화규률。재850~1200℃적온도범위내，수착오씨체화온도적승고，오씨체정립척촌경력료은정-취증-은정삼개계단。항랍강도화충격인성시험결과현시，실험강적항랍강도Rm수착오씨체화온도적승고축점증가，이충격인성칙경력료은정-강저-승고적과정。일정온도하침정상입자적조화도치료오씨체정립척촌적돌연증가；수온도승고，합금원소불단고용소도치적회화후미산석출적증다화침정상입자적유효정찰시항랍강도증가적주요원인，이일정온도하정립적불정상장대화척촌균균화칙시영향실험강충격인성적관건인소。
Experiments were performed to investigate the effect of austenitizing temperature on the mechanical properties of quenched and tempered Ti-V microalloyed steel. Metallographic and transmission electron microscopy ( TEM) observations reveal the variation of austenite grain size with austenitizing temperature. Within the temperature range of 850 to 1200℃, the austenite grain size experiences three phases, which are stable, rapidly increased, and stable again. Tensile strength and impact toughness tests show that, when the austenitizing temperature rises, the tensile strength Rm increases gradually, but the impact toughness undergoes a process of stabilizing, decreasing and then increasing. At a certain temperature, coarsening of precipitated particles leads to the sudden increase of austenite grain size. The increase of diffuse precipitates resulting from continuous solutionizing of microalloying elements with temper-ature rise and the effective pinning of precipitated particles are the main reasons for the increase of tensile strength, while abnormal grain growth and grain size uniformity at a certain temperature are the key factors that influence the toughness of the steel.