超快冷终冷温度对重加热后9Ni钢低温韧性的影响  

The Effect of UFC Final Cooling Temperature on Low Temperature Toughness of 9Ni Steel after Reheating

作　　者：田国平[1] 程知松[1] 武会宾[1] 张坤[1] 刘学利[1] 

机构地区：[1]北京科技大学冶金工程研究院,北京100083

出　　处：《新技术新工艺》2010年第11期76-79,共4页New Technology & New Process

摘　　要：本文研究了在线热处理(UFC+DQ+Online T)工艺——终冷温度对9Ni钢低温韧性的影响。利用XRD法测定了不同终冷温度对9Ni钢内回转奥氏体含量的影响,并结合热膨胀仪分析了终冷温度对过冷奥氏体转变过程的影响。研究表明,提高终冷温度有利于回转奥氏体的生成,但其稳定性随之降低,在回火后的快冷及深冷过程中发生了马氏体的二次转变,新生马氏体对9Ni钢的低温韧性非常不利;当终冷温度达到或超过320℃时,组织内出现明显的块状物质,甚至聚集在某些部位集中分布,不利于9Ni钢低温韧性的提高;终冷温度为280℃时9Ni钢的性能达到最佳。The effect of UFC＋DQ＋Online T-final cooling temperature was studied on low temperature toughness of 9Ni steel.The quantity of reversed austenite in 9Ni steel at different final cooling temperature was measured by XRD and the formation and stability of reversed austenite was studied by thermal dilatometer.Results indicated that improving the final cooling temperature is conducive to the formation of reversed austenite,but its stability decreased.New martensite which formate during fast cooling and cryogenic cooling after tempering was negative to the toughness of 9Ni steel at low temperature.When the final cooling temperature reaches or exceeds 320 ℃,bulk ferrite gathering in certain areas was negative to the toughness of 9Ni steel at low temperature.When final cooling temperature arrive at 280 ℃,low temperature toughness of 9Ni steel reached the best performance.

关 键 词：9NI钢 终冷温度 回转奥氏体 新生马氏体 

分 类 号：TG162.83[金属学及工艺—热处理] TG166.7[金属学及工艺—金属学]