Mechanical Characteristics of Conduits for the ITER Central Solenoid Conductor
Mechanical Characteristics of Conduits for the ITER Central Solenoid Conductor
复制标题
ITER 中央螺线管导体导管的机械特性
DOI：
10.2221/jcsj.54.437
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
T. Suwa
中科院分区：
文献类型：
--
作者：
K. Hamada;Y. Takahashi;T. Suwa
简介：ITER中央螺线管（CS）导体导管要求高屈服强度（在4K下> 850 MPa）、断裂韧性（在4K下> 130 MPam 1/2）以及比常规不锈钢更小的热膨胀特性和疲劳裂纹增长速率。高锰奥氏体不锈钢JK 2具有这些特性。然而，在650ºC下进行Nb 3Sn热处理后，JK 2的断裂韧性劣化。为了提高热处理后的断裂韧性，开发了低碳加硼JK 2（JK 2LB）。此外，导体制造工艺和线圈缠绕工艺中的冷加工使断裂韧性劣化。考虑到冷加工对力学性能的影响，对JK 2LB钢的氮、硼含量进行了优化。因此，生产的管道机械性能符合ITER要求。最后，总共制造了6，200根导管。本文介绍了JK 2LB的研制过程，总结了JK 2LB的力学特性。
Synopsis : The ITER Central Solenoid (CS) conductor conduit requires high yield strength (> 850 MPa at 4 K), fracture toughness (> 130 MPam 1/2 at 4 K), and smaller thermal expansion characteristics and fatigue crack growth rate than those of conventional stainless steel. High manganese austenitic stainless steel, JK2, has these characteristics. However, the fracture toughness of JK2 deteriorates after Nb 3 Sn heat treatment at 650ºC. Low carbon and boron-added JK2 (JK2LB) has been developed to improve the fracture toughness after heat treatment. Additionally, cold-working in the conductor manufacturing process and the coil winding process deteriorate fracture toughness. The nitrogen and boron contents of JK2LB have been optimized taking the impact of cold-working on mechanical performance into account. Accordingly, the mechanical performance of the conduit produced meets ITER requirements. Finally, a total of 6,200 conduits have been manufactured. This paper introduces the development process for JK2LB, and the mechanical characteristics of JK2LB are summarized.