Making calculations easier

To save time and effort in welding research and technology, TWI is currently undertaking a project to convert the leading microstructural predictive models into software programs. Over the past decade there has been an enormousincrease in computer software available to help scientists and engineers.

Calculations are taken from the various disciplines of metallurgy, physics and chemistry to create a computer model for weld microstructures and weld deposits. This will guide engineers through the complicated calculations needed tounderstand the microstructures of fusion zones in welded joints.

Programmers at TWI allow for the variables which occur during welding, such as chemical composition, heat input and joint design. These correlate with the final microstructure (volume fraction, phase chemistries, particle sizes anddistribution). This is just as accurate as traditional methods of calculation.

TWI's materials engineers are finding that, by using this new software, they can calculate at what compositions certain microstructures may be produced. This is useful where the exact compositional information is unavailable. Forexample, it is generally accepted that optimum levels of toughness in the weldmetal are achieved when the microstructure contains (normally) over 70% acicular ferrite. The computer model will validate any theoretical compositions.

By using this system, a welding engineer will save time and effort, and scientific investigations can be carried out faster and provide more information.

For further information, contact Martin Harvey: mtharvey@twi.co.uk