Experimental characterisation of mechanical properties and continuous cooling transformation analysis for structural 690 quenched and tempered high-strength steel

Material behaviour is a central factor in mechanical engineering, and reliable numerical predictions depend on the availability of accurate material data. Such parameters are essential for modelling elastic–plastic deformation, heat transfer, phase-transformation-induced volume changes, and microstructural evolution. In computational mechanics, material models are used to capture complex nonlinear responses with sufficient fidelity to reproduce real physical behaviour. In computational welding mechanics (CWM), for example, the selected material model directly affects the accuracy of predicted residual stresses and distortions. Although simplified descriptions may be adequate for global assessments, the precision of local simulation results is strongly governed by the quality of the underlying material data. In this study, the material parameters of a newly developed quenched and tempered 690 high-strength ship steel were determined using a quenching dilatometer. The mechanical properties of this steel have been characterised previously, but the present dilatometric experiments refine the material parameters required for welding simulations. The obtained data enhance the predictive accuracy of numerical welding analyses and reduce the need for empirical model calibration. Overall, this study establishes a foundation for welding simulation of high-strength shipbuilding steel, advancing the research and development of next-generation marine applications.