Drawing moulding refers to a plastic forming method in which the processed material is reduced in cross-sectional area through a mould with a certain taper hole. Various geometric cross-section profiles can be formed through drawing moulding. It is an important method for preparing wires and pipes. .
The characteristics of drawing processing are: it is conducive to the refinement of metal grains, improving the overall performance of the product, the tools and equipment used are simple, and the maintenance is convenient. In addition, drawing can obtain high precision and high surface quality without waste Material is an economical processing technology.
In recent years, many scholars have improved the traditional drawing process and developed many new drawing processes. Specifically as follows:
1. Anti-tension drawing
It is a processing method in which the blank is pulled in the opposite direction at the back end of the drawing die during drawing. This method greatly reduces the wear of the drawing die and at the same time reduces the phenomenon of the drawing wire or the profile being broken.
2. Roller die drawing
It is a production process that combines drawing and rolling together, that is, replacing the traditional hole die with a pass roll, turning most of the sliding friction into rolling friction, greatly reducing the friction resistance, and realizing high-speed drawing , This technology is mainly used in forming special-shaped steel pipes with complex interfaces.
3. Forced lubrication drawing
It is equipped with a slender pressurizing tube or pressurizing die at the front end of the drawing die. When drawing, by means of the viscosity of the billet and the vulcanized additive when it is drawn, the high-viscosity additives are brought into the drawing die, forcing the additives into the die hole , A layer of lubricating film is formed between the blank and the die, thereby generating a hydrodynamic effect and reducing the effect of friction.
4. Dieless drawing
It is a flexible plastic processing technology that does not use traditional drawing dies, but relies on the properties of metal deformation resistance to change with temperature. It is a processing method that uses the heating and cooling control of a cold heat source. It solves the problems of multiple drawing passes, small pass deformation, and low production efficiency in traditional drawing, but the uniformity of the finished product is poor, and the product quality is unstable.
Such as ultrasonic vibration drawing, superplastic drawing, etc. which apply ultrasonic vibration to the drawing die.