Low alloy seamless steel tube drawing forming

By drawing die is continuous and stable process; drawn pipes or rods in drawing machine is intermittent operation. And other metal processing, like drawing lubricant can reduce stress and energy consumption, reduce mold crack and maintain a lower temperature. Because the surface finish of the product is very important to draw an indicator (usually people would think that the surface polished), drawing lubricating mechanism is very complex. On the one hand, a good lubricant due to mixed lubrication on the workpiece and the die being formed at the interface to reduce friction. On the other hand, if the lubricant film is too thick (depending on the viscosity of the metal grain size and a lubricant), the surface of the product by mixing and lubrication can not be polished. Thus, there is a thin lubricating film is desirable, which may be obtained by a low viscosity of the lubricant and mold large angle to solve the pullout. But this time the contact pressure die and the workpiece may be significant asked. If you want to be satisfied with the mold life, usually have sufficient lubricating film strength, which can be through the use of extreme pressure agents and various other additives resolved. Tube drawing machine is imported from abroad a special device, it is rough low alloy seamless drawn directly into a high-precision surface finish low alloy seamless steel pipe, due to the low alloy seamless steel pipe in the drawing process to be subjected to longitudinal and lateral forces acting in all directions, low alloy seamless steel pipe surface by both a high pressing force and the pulling force, at this time in a mixed lubrication lubrication state (fluid and boundary lubrication).

In words, the medium is a layer boundary lubrication properties of different films in the presence of the friction surface portion, the thickness of this layer of thin film 0.1 μm or less, can not prevent the contact friction surface asperity, but good lubricating properties, to reduce friction. State border membrane depends on the nature of the shape and boundary friction surface film. The thickness of the boundary layer of the film is based on several elements, which is why generally can not see with the naked eye. However, its impact can not be underestimated, it can reduce friction, improve the surface finish of the workpiece. Boundary film formation process can be divided according to their membrane and adsorption reaction film into two categories. Adding a small amount of the lubricating oil can be formed or enhancing substance adsorbed film called lubricity additive; capable of forming a film or enhance the reaction extreme pressure additives. Therefore requires its oily lubricant must have excellent abrasion resistance and extreme pressure, otherwise low-alloy seamless drawn uneven thickness, surface finish below standard, seamless steel pipe forming oil must be based on the principle of low-alloy adding oil additives and extreme pressure additives, while also control the viscosity of the oil.