Abstract: A method produces a magnetostrictive torque sensor which detects a steering torque applied to a steering shaft by electrically detecting distortion of magnetostrictive films provided on a surface of the steering shaft. A plating step forms the magnetostrictive film on the surface of the steering shaft, and a heat treatment step heat treats the magnetostrictive film on the steering shaft. During the heat treatment step, hydrogen in the magnetostrictive film is decreased so that a hydrogen desorbing peak around 120° C. disappears when the magnetostrictive film is heated after the heat treatment step.

Abstract: A method produces a magnetostrictive torque sensor which detects a steering torque applied to a steering shaft by electrically detecting distortion of magnetostrictive films provided on a surface of the steering shaft. A plating step forms the magnetostrictive film on the surface of the steering shaft, and a heat treatment step heat treats the magnetostrictive film on the steering shaft. During the heat treatment step, hydrogen in the magnetostrictive film is decreased so that a hydrogen desorbing peak around 120° C. disappears when the magnetostrictive film is heated after the heat treatment step.

Abstract: A method for producing a magnetostrictive torque sensor which detects steering torque applied to a steering shaft. A magnetostrictive film is formed on the steering shaft and then subjected to heat treatment, which decreases a weight ratio of hydrogen included in the magnetostrictive film. Thermal desorption gas analysis is performed on at least a portion of the magnetostrictive film undergoing the heat treatment step. A portion of the magnetostrictive film having a thickness of 40 ?m or less is heated at a temperature rise rate of 5° C. per minute. A weight ratio of a total amount of hydrogen desorbed from the portion of the magnetostrictive film due to the heat treatment to a weight before the heat treatment is no more than 3 ppm up to 150° C., wherein the weight ratio is no more than 10 ppm up to 300° C., and no more than 15 ppm up to 400° C.

Abstract: A magnetostrictive torque sensor detects steering torque applied to a steering shaft by electrically detecting distortion of magnetostrictive films provided on a surface of the steering shaft. When the films are removed from the surface of the steering shaft to perform thermal desorption gas analysis, the thickness of the films is at 40 ?m, and in the thermal desorption gas analysis, the films are heated at a temperature rise rate of 5° C. per minute, in which the films contain hydrogen to satisfy at least one of the following conditions: a ratio of the weight of hydrogen desorbed by the heating from the film by the time the film reaches 150° C. to the weight of the film before the heating being at or below 3 ppm; the ratio for by the time the film reaches 300° C. being at or below 10 ppm; and the ratio for by the time the film reaches 400° C. being at or below 15 ppm.