PURPOSE: To enable good press forming to be effected without use of any lubricant by adjusting in a specific range a forming quantity of chromate treated film to be formed on a zinc or zinc alloy plated steel sheet, and the particle diameter of a solid lubricant for adding into organic resin to be applied thereto.
CONSTITUTION: On a zinc or zinc alloy plated steel sheet, a chromate film of 200mg/m2 per one surface by metal Cr conversion in a chrome adhering quantity, and a resin coated layer of 0.2-4.0g/m2 in a applying quantity containing a crystalline solid lubricant of 3-100μm in the particle diameter are formed in this order. For a solid lubricating agent, an organic crystalline solid lubricant is selected and, for example, a wax of polyolefin or paraffin or fluorocarbon resin is preferable, and one of 120°C or higher in melting point is adapted herein. As for the additional quantity of the solid lubricant to base resin, it is preferable that the range of organic polymer (base resin) : a solid lubricant=(1:0.02)-(1: 0.4). As for resin for coating, it is desirable to select one whose Tg is 20-120°C. Besides, the additive quantity of silica to the resin is preferably allowed to be in the range of organic polymer (base resin) : silica=(1:0.05)-(1: 1).