Long-Term Strength of 22Kh2G2AYu Reinforcing-Bar Steel during Corrosion Cracking Tests in a Boiling Nitrate Solution

The influence of the strength, the tempering temperature, and the time between the end of rolling and the beginning of tempering on the stress corrosion cracking resistance of strength class A1000 reinforcing bars made of 22Kh2G2AYu steel in a boiling nickel solution (60% Ca (NO3)2 + 5% NH4NO3 + 35% H2O) at 110°C is studied. Reinforcing bar samples are found to have a relatively low long-term strength. After tempering at 150–450°C for 2 h, the mechanical properties of the steel remain within the strength class A1000 range and the long-term strength increases weakly. Tempering at 500–600°C for 2 h leads to an increase in the long-term strength, but the steel undergoes softening. Storage of the rolled reinforcing bars before tempering for 2–48 h weakly affects the long-term strength.