Water-based lubricating coating agent for metal material, surface-treated metal material, and method for forming lubricating coating for metal material

A water-based lubricating coating agent for a metal material, the agent having pH of 2.0 to 6.5, which is obtained by blending:

• at least one lubricating component, that is not a black-based solid lubricant, comprising carrier particles (C);
• and
• a chemical conversion component that comprises at least one of the group consisting of a primary sodium phosphate, oxalic acid, and ammonium molybdate,
• wherein a concentration of the lubricating component is 5 mass % or more in mass ratio to a total solid content mass in the lubricating coating agent, and a concentration of the chemical conversion component is 0.3 to 8 mass % when a total mass of the lubricating coating agent is regarded as 100 mass %,
• wherein the carrier particles (C) comprise a lipophilic lubricating component (A) and a cleavage solid lubricant (B),
• wherein the lipophilic lubricating component (A) comprises at least one of the group consisting of plant oil, mineral oil, and synthetic oil,
• wherein the cleavage solid lubricant (B) comprises a layered clay mineral (B2),
• wherein the layered clay mineral (B2) comprises at least one of the group consisting of kaolinite, talc, and mica, and is 30 μm or less in average particle size, and
• wherein the carrier particles (C) are particles that include the lipophilic lubricating component (A) between particles of and/or between layers of the layered clay mineral (B2).