Predicting and eliminating material flow defects

Laps

Laps occur in the areas of the free surface of a workpiece being formed due to an unsustainable material flow. The surface contacts itself and closes, forming a flaw. The automated finite-element mesh generation makes it possible to identify the time and location, where a lap occurs, by simulation and then track the dimensions and location of this defect in subsequent transformations and in the finished product. Having a complete picture of the flaw formation, the process engineer determines the possibly ways of its elimination, verifies their efficiency by simulating the modified versions and finds the best possible solution to eliminate the lap.

Flow-through defects

A flow-through type defect occurs through dragging the surface material layers into the body of a forging owing to an extensive local strain directed toward the center. The flaw occurs at the end of a transformation when the material flows vigorously from the fully filled cavity of one of the dies to the cavity of the other die, which is not filled yet. To identify the initiation of the faults of this kind in a forging, QFORM uses its dedicated capabilities for the visualization of the material flow in under surface material layers.

Increasing tools durability

QFORM makes it possible to simulate stresses and deformations both in one-piece and composite pre-stressed dies comprising several parts, e. g. blocks, tire rings, hard-alloy inserts, pushers, etc. Simulation is performed for the interlocked set of the bodies constituting the tool and working as an assembly. The parts of a composite tool can be put together with a clearance or interference fit. Using the software, the process engineer can analyze the impact of the material flow nature and dies design on the stress value in these and find the most suitable ratio of the parameters to ensure the best tools durability.

 

Economic benefits of simulation

Instead of costly forging trials, the process engineer can find a way of reducing the workpiece weight by computer simulation. This saves the costs by speeding up the development, saving the material and enhancing the tools durability.

Economic benefits of simulation

Efficiency in the use of simulation is based on the feasibility of practical solutions to a wide range of the engineering problems encountered during the development and optimization of the technology and tools. Optimized material flow, reduced material and energy costs, increased tool life, and improved forming accuracy can be the tasks to be solved. The ability to predict forming flaws and determine the ways of remedying these is, of course, an essential feature of any simulation software.