Destruction Features of Steel Inductors with Nitrided Working Surface Under Strong Magnetic Field Generation

摘要

The work was aimed to study the influence of plasma nitriding on electrical and mechanical properties of steels, meant for pulsed magnets production, and their durability in pulsed high magnetic field. For this purpose single-turn coils of several domestic steel grades, including 30KhGSA, 40Kh, 50KhGA, 38Kh2MYuA, 3Kh2V8F, 4Kh5V2FS, and U8A, have been produced and examined. Steel inductors had an inner channel surface modified by ion plasma nitriding at low temperature (400, 500°C). The coils without plasma treatment were also studied for comparison. Temperature dependence of electrical resistivity of nitrided steels has been investigated. A microstructure and microhardness profiles across near-surface layer of treated and untreated inductors, applied for high magnetic field generation, has been studied. The full-scale testing of the coils was performed using an inductor system with magnetic flux concentrator as a test subject. Magnetic field of about 50 T in amplitude and rising time of 6 microseconds inside the concentrator was generated by the outer coil. The concentrators of different steels with and without plasma treatment were compared on durability in high pulsed magnetic field and their destruction features were studied.