GALVANNEALED STEEL SHEET AND PROCESS FOR PRODUCTION THEREOF

摘要

A galvannealed steel sheet includes: a steel sheet; a galvannealed layer; and a Mn-P based oxide film. A Zn-Fe alloy phase in the galvannealed layer is measured by X-ray diffractometry. The value of a diffraction intensity T(2.59 Å) off phase divided by a diffraction intensity ´ 1 (2.13 Å) of ´ 1 phase is less than or equal to 0.1. The value of a diffraction intensity ¶(1.26 Å) of ¶ phase divided by a diffraction intensity ´ 1 (2.13 Å) of ´ 1 phase is greater than or equal to 0.1 and less than or equal to 0.4. The Mn-P based oxide film is formed using 5 to 100 mg / m 2 of Mn and 3 to 500 mg / m 2 of P on a surface of the galvannealed layer.