Abstract:

Shear pin coated with plasma-sprayed alumina for low-voltage electrical insulation, used in the correction coil support (CCS) to prevent from eddy current loops between toroidal field coils (TFC), is reported. The stress analyses of shear pins were performed using ANSYS according to the practical working environment. The characteristics of coating of 316L stainless steel at liquid nitrogen temperature were investigated. After 5000, 10000 and 30000 times’ rolling with radial loading, the electrical resistance test indicated that the surface resistivity and volume resistivity is more than 10⁹Ω•m^-2 and 10¹⁰Ω•m respectively. And the coating is free from cracks, flakes and debonding, qualified and can be utilized for the CCS of ITER.

Key words: ITER, Shear pin, Alumina, Insulation resistance

摘要：

采用大气等离子喷涂方法在316LN不锈钢剪切销表面喷涂了Al₂O₃+3%TiO₂绝缘涂层，采用NiAl作为粘结层，得到了性能优良的绝缘保护涂层。按照ITER实际运行环境，采用ANSYS分析方法对剪切销进行应力分析，并在低温(液氮，77K)环境下对剪切销加载后进行循环往复摩擦磨损试验。循环5000、10000以及30000周后采用2点和3点法分别测定了涂层的表面电阻和体积电阻，剪切销表面电阻率均大于10⁹Ω•m^-2，体积电阻率均大于10¹⁰Ω•m，表明涂层具有较高的绝缘电阻，满足ITER所需工程条件。

关键词: ITER, 剪切销, 氧化铝, 绝缘电阻