What is the term for the induction field value that remains when the H field strength returns to zero?

The term that represents the induction field value remaining when the magnetic field strength, or H field, returns to zero is referred to as residual magnetism. This phenomenon occurs in ferromagnetic materials where, after being magnetized, the material retains a certain amount of magnetization even when the external magnetic field is removed.

Residual magnetism is important in non-destructive testing since it can affect how magnetic materials respond to eddy current testing. Understanding this concept helps in assessing the material’s performance and making accurate evaluations during inspection processes.

Other terms, while relevant to magnetic properties, do not define this specific behavior. Coercive force refers to the strength of the magnetic field required to reduce the magnetization to zero. The saturation value pertains to the maximum magnetization a material can achieve under an applied magnetic field. Hysteresis loss describes energy loss in the form of heat due to the lagging of magnetization behind the applied magnetic field, rather than indicating residual magnetism.