Spark plug for use in internal combustion engine

摘要

A spark plug for use in an internal combustion engine includes a tubular insulator having an axial hole extending therethrough; a center electrode fitted into the axial hole and having a distal end portion protruding from a distal end of the insulator; and a ground electrode arranged such that at least a portion of spark discharge generated between the ground electrode and the distal end portion of the center electrode includes creeping discharge along the surface of the distal end portion of the insulator. The distal end portion of the center electrode contains Ni as a primary component in an amount of 80 wt % or more and Fe and Cr as secondary components in a total amount of 2.5 wt % to 10.0 wt % and further contains Al as a secondary component in an amount of 0.2 wt % to 0.8 wt %.