1.4571 | X6CrNiMoTi17-12-2 Stress corrosion cracking

The primary cause of damage was a relative movement between the seal and the component surface, so that the protective chromium oxide top layer was repeatedly destroyed. The transcrystalline stress corrosion cracking (SCC) was caused by a very high chloride content in the process water and a neighbouring weld seam, which resulted in excessive stresses in the component.

During etching, many submicroscopically small precipitates were visible in the centre of the grain as well as along grain boundaries. The C content is too low for carbides and the Ti content in the alloy leads to the formation of pink-coloured titanium carbonitrides. The target chemical composition met the specifications.