Fractographic studies of stress corrosion cracking behaviour of AISI 4340 steel in 0.5 N NaCI solution near its lower temper martensite embrittlement range

Based on the data of the literature for intercrystalline stress corrosion cracking (SCC) and hydrogen embrittlement of the high-strength steel AISI 4340, determination of the so far unknown effects of tempering treatment around the low temper-martensite embrittlement range (between 175 and 285°C) on the fracture appearance. Variation of the stress intensity and applied potentials in 0.5 N NaCI solution. Discussion on obtained fractographs for a better understanding of the SCC mechanism.