固溶处理对ITERTF铠甲材料-316LN低温断裂延伸率的影响  

EFFECT OF SOLUTION ANNEALING TREATMENT ON THE CRYOGENIC ELONGATION OF ITER TF JACKET MATERIAL-316LN

作　　者：黄传军[1] 李来风[1] 吴智雄[1] 黄荣进[1] 李静文[1] 李山峰[1] 秦经刚[2] 刘华军[2] 武玉[2] 

机构地区：[1]航天低温推进剂技术国家重点实验室,中国科学院理化技术研究所,北京100190 [2]中国科学院等离子体物理研究所,合肥230031

出　　处：《低温物理学报》2013年第2期117-121,共5页Low Temperature Physical Letters

基　　金：ITER国内配套(批准号:2011GB112004,2011GB112005);国家自然科学基金(批准号:51171162,51177163)资助课题~~

摘　　要：ITER TF线圈导体采用CICC(cable-in-conduit conductors)结构,其铠甲采用316LN奥氏体不锈钢圆管.ITER TF导体制备需要穿缆、缩管、650℃/200h热处理、磁体绕制等工艺.ITER TF超导线圈使用超临界氦冷却(4.5K),因此需要研究此温度下铠甲材料的力学性能尤其是拉伸性能.我们前期研究表明:热处理后316LN奥氏体不锈钢铠甲材料的低温(4.2K)断裂延伸率为15%左右,这低于ITER设计要求.通过优化固溶处理制度,经冷作变形及热处理后316LN奥氏体不锈钢铠甲材料的低温断裂延伸率显著提高到34%.研究结果表明优化的固溶处理工艺使316LN奥氏体不锈钢晶粒细化、晶粒均匀,从而提高了材料低温断裂延伸率.本文还对晶粒度对316LN不锈钢低温拉伸断裂行为的影响进行了阐述.The cable-in-conduit conductors （CICCs） for ITER toroidal field （TF） coils selects austenitic 316LN austenitic stainless steel as jacket material, which requires post-aging treatment at 650 ℃over 200 hours for Nba Sn superconducting materials. Special mechanical properties of the 316LN jacket material at the operating temperature of the TF magnet are required due to the high electromagnetic forces. Our previous investigations indicated that theelongation of the 316LN jacket material at 4. 2 K was around 15~//00, which does not satisfy ITER＇s requirement. However, the elongation at failure of the 316LN jacket material at 4. 2 K is found to be increased to around 34~ with optimized solution annealing treatment approach. In the present work, metallographic investigations were per- formed on both un-optimized and optimized solution annealed austenitie 316LN stainless steel and the influences of homogeneity of grains on the elongation at failure at 4. 2K is interpreted. Results indicate that the optimized solution annealing treatment can improve the homogeneity of the grains, which results in the increase of the elongation at failure at cryogenic temperature.

关 键 词：316LN奥氏体不锈钢 固溶处理 热处理 低温 断裂延伸率 晶粒度 

分 类 号：TL627[核科学技术—核技术及应用]