Chloridinduzierte transkristalline Spannungsrisskorrosion hochlegierter austenitischer CrNiMo- und CrMnN-Stähle

Research output: ThesisDoctoral ThesisResearch

Abstract

The susceptibility to chloride induced transgranular stress corrosion cracking (SCC) of 13 different solution annealed CrMnN- and CrNiMo-alloys has been investigated by different test methods (Constant-Load Tests, Slow-Strain-Rate Tests, electrochemistry and TEM). 45% MgCl2 solution at 155°C and 62% CaCl2 solution at 123°C were used as corrosive testing media while glycerine was used as inert testing solution in SSRT. Five alloys were tested with various degrees of cold working (CW) to determine the influence of CW on SCC resistance at which the main result is that CW doesnot improve the SCC resistance. While the absolute SCC threshold stress isnot influenced by CW, the relative SCC threshold stress is reduced systematically with higher degrees of CW. All samples showed a transgranular fracture appearance with a following ductile overload breakage. TEM investigations gave the slip-step dissolution model as the predominant crack initiation mechanism while for the crack propagation mechanism a combination of hydrogen embrittlement and film induced SCC is assumed.

Details

Translated title of the contributionChloride induced transgranular Stress Corrosion Cracking of highly alloyed austenitic CrNiMo- and CrMnN-Steels
Original languageGerman
Supervisors/Advisors
Publication statusPublished - 2006