METHOD FOR MANUFACTURING NON-PHOSPHATE COATED METAL MATERIAL FOR COLD HEADING-PLASTIC WORKING PROCESS

A non-phosphate coated metal material for plastic working includes a metal material, a coating layer formed on a surface of the metal material, and a lubrication layer on the coating layer. The coating layer includes calcium tetraborate. A method for manufacturing a non-phosphate coated metal material includes a pre-treatment process to remove foreign matters or scale from a surface of a metal material, a coating treatment process to form a coating layer on the surface of the metal material by dipping the metal material, which is subject to the pre-treatment process, into a coating agent, and a lubrication treatment process to form a lubrication layer on the coating layer through the contact between the coated metal material and a lubricating agent. The coating agent includes a non-phosphate treatment solution including at least one borate selected from sodium tetraborate and a hydrate thereof, sodium nitrite, calcium hydroxide, and water.