| abstract |
Provided are a magnetic circuit capable of being manufactured inexpensively due to omission of formation of a corrosion-resistant metallic surface film as well as a voice coil motor or an actuator by utilizing the same. The magnetic circuit comprises yoke members prepared from a plate material of 0.1 mm to 5 mm thickness of a martensite-type, ferrite-type or precipitation-hardening stainless steel material or a Cr-based heat-resistant steel material containing 0.0001-1% (% by mass, the same hereinbelow) of C, 0.0001-5% of Si, 0.001-2% of Mn, 0.0001-0.1% of P, 0.0001-0.2% of S, 0.0001-5% of Al, 0.0001-0.1% of O, 0,0001-0.1% of N, 0.0001-1% of Ni and 10.5-30% of Cr together with at least one alloying element selected from Ti, Co, Cu, Zr, Nb, V, Mo, W, Ta and B as the additive elements in a total amount of 0.0001-5%, the balance being Fe. |