Solenoid valve and method for manufacturing the same

A solenoid valve comprising:

• a pipe formed of a ferromagnetic material containing 15 mass % or more to 18 mass % or less of Cr;
• wherein the pipe comprises a first portion and a second portion, wherein a diameter of the second portion is less than a diameter of the first portion;
• an electromagnetic coil;
• a valve body;
• a movable component configured to move in response to a magnetic force;
• and
• a stationary component located upstream of the movable component;
• wherein each of the movable component and the stationary component are encompassed within the pipe;
• wherein the second portion further comprises a first receiving portion and second receiving portion and wherein the first receiving portion is configured to receive the stationary component and the second receiving portion is configured to receive the movable component;
• a filter disposed upstream of the stationary component, wherein the second portion is configured to increase magnetic resistance between the first receiving portion when the stationary component is received in the first receiving portion and the second receiving portion when the movable component is received in the second receiving portion;
• wherein a part of the pipe includes a reform portion;
• wherein the reform portion has a composition in which a component of the ferromagnetic material is mixed with a component of a Ni-containing material;
• and
• wherein e/d which is a ratio of a maximum deformation amount e of an outer circumferential surface side of the reform portion of the pipe with respect to a thickness d near the reform portion of the pipe is 0.5 or less, and c/d which is a ratio of a maximum deformation amount c of an inner circumferential surface side of the reform portion of the pipe with respect to the thickness d of the pipe is 0.5 or less.