关键词: 大规格风电螺栓钢, 热处理, 轧制工艺, 组织, 力学性能

Abstract: Aiming at the problems of low percentage reduction of area and insufficient hardenability in the core of large-scale wind turbine bolt steel 42CrMoA, the property improvement process of 61 mm wind turbine bolt steel 42CrMoA was investigated through quenching and tempering, annealing + quenching + tempering, and normalizing + quenching + tempering experiments after hot-rolling. The results indicate that the microstructural state of steel prior to quenching and tempering has a significant impact on its mechanical properties. After normalizing at 900 ℃ followed by quenching and tempering, the mechanical properties of the steel can be improved. By adopting controlled rolling and controlled cooling processes, the as-rolled microstructure of the rolled materials is improved, Brinell hardness is reduced, and ensuring that the mechanical properties of quenched and tempered large-scale wind turbine bolt steel fully meet the standard requirements.

Key words: large-scale wind turbine bolt steel, heat treatment, rolling process, microstructure, mechanical properties