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The presented approach is based on experimental observations which clearly show that the hot cracking phenomenon is a result of accumulation of macroscopic tensile strains in a microscopic intergranular film of liquid enriched with segregating elements at the final stage of solidification. The modeling takes into account the effects of strain accumulation as well as the influence of the microstructure and the thermo-dynamical properties of the welded material. The integrated approach provides a clear phenomenological interrelation between parameters of the welding process, properties of the welded material and the cracking susceptibility. It is successfully used for the development of technological means, such as a multibeam welding, for eliminating solidification cracking.

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Heat Treatment of martensitic stainless steels is used to increase the hardness that is caused by several microstructure changes. But such a treatment does affect both mechanical properties and corrosion resistance. Existing studies about the effect of austenitizing on the material properties and the corrosion resistance show contradictory results. Here we reveal the different effects of austenitizing on the passive layer of stainless steel and thus the corrosion resistance, thermodynamic phase calculations, microstructure investigations and various electrochemical measurements are performed. By potentiodynamic polarization scans the pitting potential, the critical pitting potential and the corrosion current are determined. Impedance spectroscopy are used to gain deeper insight into the passive layer properties. The results show a strong dependency of the corrosion behavior on the heat treatment where the governing corrosion mechanism are affected differently.