The present invention relates to a casting mold surface treatment method, and a casting mold having a carbon film formed on its surface by this surface treatment method. In the casting process, a die lubricant is gene...The present invention relates to a casting mold surface treatment method, and a casting mold having a carbon film formed on its surface by this surface treatment method. In the casting process, a die lubricant is generally applied to a molding surface of the casting mold, by which the product is released more easily when the molded product is to be removed from the casting mold. However, when casting is repeated, the material may stick to the casting mold, and removing the product from the casting mold becomes more difficult. This problem can be resolved by covering the surface of the casting mold with a carbon film. The carbon film prevents the molten metal and the base material of the casting mold from making direct contact, suppressing the sticking of molten metal to the casting mold and an increase in release resistance.展开更多
A pilot wire drawing machine as well as wire end-pointing roller was developed. Using these machines, a wire drawing test for four different coating materials and two different lubricants was performed as the reductio...A pilot wire drawing machine as well as wire end-pointing roller was developed. Using these machines, a wire drawing test for four different coating materials and two different lubricants was performed as the reduction ratio increased from 10% to 30%. Materials used for a substrate in this study are plain carbon steel （AIS11045） and ultra low carbon bainite steel. To compute the friction coefficient between the coating layer of wire and the surface of die lbr a specific lubricant, a series of finite element analyses were carried out. SEM observations were also conducted to investigate the surface defects of wire deformed. Results show that the behavior of drawing force varies with the lubricant-type at the initial stage of drawing. The powder-typed lubricant with a large particle causes the retardation of lull lubrication on the entire contact surface and the local delamination of coating layer on the wire surface. As the flow stress of a substrate increases, the delamination becomes severe.展开更多
文摘The present invention relates to a casting mold surface treatment method, and a casting mold having a carbon film formed on its surface by this surface treatment method. In the casting process, a die lubricant is generally applied to a molding surface of the casting mold, by which the product is released more easily when the molded product is to be removed from the casting mold. However, when casting is repeated, the material may stick to the casting mold, and removing the product from the casting mold becomes more difficult. This problem can be resolved by covering the surface of the casting mold with a carbon film. The carbon film prevents the molten metal and the base material of the casting mold from making direct contact, suppressing the sticking of molten metal to the casting mold and an increase in release resistance.
基金supported by research funds from Dong-A University, Korea
文摘A pilot wire drawing machine as well as wire end-pointing roller was developed. Using these machines, a wire drawing test for four different coating materials and two different lubricants was performed as the reduction ratio increased from 10% to 30%. Materials used for a substrate in this study are plain carbon steel （AIS11045） and ultra low carbon bainite steel. To compute the friction coefficient between the coating layer of wire and the surface of die lbr a specific lubricant, a series of finite element analyses were carried out. SEM observations were also conducted to investigate the surface defects of wire deformed. Results show that the behavior of drawing force varies with the lubricant-type at the initial stage of drawing. The powder-typed lubricant with a large particle causes the retardation of lull lubrication on the entire contact surface and the local delamination of coating layer on the wire surface. As the flow stress of a substrate increases, the delamination becomes severe.
