RELATION STRUCTURE - FRACTURE RESISTANCE IN PROCESS OF ESTIMATE THE WELDABILITY OF LOW ALLOY STEELS

Numerical weldability analysis is a new powerful research and development tool which is useful for metallurgistics technologist and design engineers. Saying strictly the numerical analysis of weldability comprises thermodynamic, thermomechanical and microstructural modelling of the welding process. The fracture resistance of welded joints is mainly characterised by normalised parameters: SU1 = K-ITH / K-IC for cold cracking or in the exploitation condition by SU2 =delta/delta(C) or J/J(C) , SU1 not equal SU2. Conclusions from the theoretical analysis form a basis to an assessment measure of the stress state parameter S-P. as a physical measure of the deformation and effort of the mismatched weld joints. There also was made characteristic of the effect on the inclination of the layer (W) on the form of fracture. Finally, some aspects of estimation of the K-C and K-IC values for the layer (W) with the SINTAP programme overview are presented.