Abstract: Orthogonal test method was used to study the relationship between heat treatment process and mechanical properties of the 3379BA1 steam turbine blade steel. The results show that the order of factors affecting the mechanical properties of the tested steel is tempering temperature, quenching temperature, tempering time, quenching time, and the optimal heat treatment process parameters are obtained as follows: quenching at 1050 ℃(holding for 60 min, oil cooling) and then tempering at 700 ℃(holding for 120 min, air cooling). Through test verification, the 3379BA1 steel treated under the optimal heat treatment can meet the property requirements, the average value of impact absorbed energy is higher by about 10 J than before the process optimization, and the yield ratio reaches 87.3%.

Key words: 3379BA1 steam turbine blade steel, orthogonal test, heat treatment, mechanical properties