| 摘要 |
PROBLEM TO BE SOLVED: To dissolve such problem as phosphorizing in a heat treatment after drawing and to improve the working degree by treating a carbon steel pipe with liquid composed of titanium compound and phosphoric acid and successively, executing cold-drawing while coating a specific lubricating oil. SOLUTION: The carbon steel pipe is dipped into the solution of compound composed of the titanium-containing compound and the phosphate and adjusting the pH to 8-11, and dried and the phosphorus is stuck to <=100mg/m<2> . On the inner and the outer surfaces of the carbon steel pipe applying this treatment, Fe and the phosphate on the steel pipe surface, are reacted to produce iron phosphate and also, the phosphate and titanium oxide are stuck. On the carbon steel pipe after forming this coating, while coating the lubricating oil composed of the compound of fat and oil having >=21wt.% S content and olefin on the inner and the outer surfaces, the cold-drawing at 45% working degree is executed. By this method, the drawings at the two times can do only at one time of the drawing work. Further, the cabon steel pipe having smoothness and metallic glossness and reducing chatter caused by reduction of friction coefficient is obtd. |
