Structure, properties, and resistance to stress-corrosion cracking of a nitrogen-containing austenitic steel strengthened by thermomechanical treatment

Resumo

The results of comparative studies of the structure, mechanical properties, and resistance to stresscorrosion cracking (SCC) in the chloride solutions of a Cr–Mn–Ni austenitic nitrogen-containing steel (20Cr–6Ni–11Mn–1.5Mo–N–V–Nb) produced with the use of different regimes of the high-temperature thermomechanical treatment (HTTMT) have been presented. An unfavorable effect of the grain-boundary precipitates of the nitride phase on the impact toughness and resistance to SCC has been found. It has been shown that the strengthening of nitrogen-containing steel upon HTTMT, which ensures an increase in the yield stress by 1.8 times compared to the austenitized state, does not decrease the resistance to SCC.