Galvanized steel sheet, method for manufacturing the same, and method for manufacturing press-formed product

A method for manufacturing galvanized steel sheet, comprising the step of:

• temper rolling a galvanize steel sheet to adjust the filtered centerline waviness Wca to 0.7 μm or less;
• adjusting a surface texture of the temper-rolled galvanized steel sheet by blasting solid particles against a surface of the galvanized steel sheet;
• the surface texture being at least one selected from the group consisting of a mean roughness Ra on the surf ace of the steel sheet, a peak count PPI on the surface of the steel sheet, and a filtered centerline waviness Wca on the surface of the steel sheet;
• the step of adjusting the surface texture comprising:
• (a) adjusting the mean roughness Ra on the surface of the steel sheet to a range of from 0.3 to 3 μm;
• (b) adjusting the peak count PPI on the surface of the steel sheet to 250 or more;
• and
• (c) adjusting the filtered centerline waviness Wca on the surface of the steel sheet to 0.8 μm or less.

A method for manufacturing galvanized steel sheet comprising the step of adjusting a surface texture of a galvanized steel sheet by blasting solid particles against the surface of the galvanized steel sheet;

• the surface texture being at least one selected from the group consisting of a mean roughness Ra on the surface of the steel sheet, a peak count PPI on the surface of the steel sheet, and a filtered centerline waviness Wca on the surface of the steel sheet;
• the step of adjusting the surface texture comprising at least one step selected from the group consisting of:
• (a) adjusting the mean roughness Ra on the surface of the steel sheet to a range of from 0.3 to 3 μm;
• (b) adjusting the peak count PPI on the surface of the steel sheet to 250 or more;
• and
• (c) adjusting the filtered centerline waviness Wca on the surface of the steel sheet to 0.8 μm or less,
• wherein the step of adjusting the surface texture comprises blasting solid particles having average particle sizes of from 30 to 300 μm against the surface of the galvanized steel sheet at a blasting density of from 0.2 to 40 kg/m2, using a wheel blast machine having a distance of 700 mm or less between a rotational center of a wheel thereof and a steel strip.

A method for manufacturing press-formed product, comprising:

• a first step of preparing a galvanized steel sheet member having a dimple-pattern surface, the dimple-pattern surface having a mean roughness Ra of 0.3 to 3 μm, and a peak count PPI expressed by the formula:
• −50×Ra (μm)+300<PPI<600;
• and
• a second step of applying press-forming to the member to obtain designed shape of press-formed product,
• the first step of preparing a galvanized steel sheet member comprising adjusting a surface texture of a galvanized steel sheet by blasting solid particles having average particle sizes of from 10 to 300 μm against a surface of the galvanized steel sheet at a blasting density of from 0.2 to 40 kg/m2.