Improving the Design of Piercing Tools
Durability of piercing tools is a key performance indicator in beamless tubes rolling process, because it affects significantly not only tube output, but also product quality.
The main reason why piercing tools show low resistance is overheating of their working surface to high temperatures causing decrease in strength of the surface layer, welding on to a tube shell and, as a result, its prompt depletion.
The challenging task of the TMEC Team in the project Improving the Design of Piercing Tools was meeting the demand of Client’s requirements as to piercing tool durability.
For the purpose of retrofitting the design of piercing tools, a mathematical model of piercing was developed. The simulation included solving the problem of thermal conductivity in the solid body of the tool and convective heat transfer in the inner cavity that allows to determine the temperature field of the tool during the entire process time of 15-18 seconds and to evaluate the combined effect of temperature and power loads. The temperature field was subsequently used in evaluation of the mechanical states of the tool.
Simulation of the Piercing Process
On the basis of study TMEC developed a number of piercing tools with predicted enhanced KPI. The result of further tests is increase in durability of the tool by 17%.
A technical audit conducted by TMEC engineers shew drawbacks of the existent hydraulic system of the tool resulting in unjustified pressure drop at its several spots and reducing flow-rate of the coolant. Thus, the new design of the hydraulic system was also developed.