The quenching and partitioning steel is the representative of the third generation of advanced high-strength steel. The effect of quenching temperature on the microstructure and mechanical property of ferrite-containing quenching and partitioning steel was studied by intercritical annealing quenching and partitioning processes. When preparing a test steel with a tensile strength of 1300 MPa and total elongation of 19%, it is found that the actual optimum quenching temperature was lower than that calculated according to the constrained carbon equilibrium. The results indicate that the martensite start temperature of the austenite was overestimated when considering the diffusion of carbon only. Austenite grain size which is affected by low temperature and the existence of ferrite during intercritical annealing influenced the optimum quenching temperature. A scheme considering the diffusion of various alloying elements and austenite grain size was proposed and verified. Using this scheme, the optimum quenching temperature of intercritically annealed quenching and partitioning steel with complex microstructures was well predicted.

淬火和分隔钢是第三代高级高强度钢的代表。通过临界退火退火和分区工艺研究了淬火温度对含铁素体淬火和分区钢的组织和力学性能的影响。当制备具有1300MPa的抗拉强度和19％的总伸长率的试验钢时，发现实际的最佳淬火温度低于根据约束碳平衡所计算出的最佳淬火温度。结果表明，仅考虑碳的扩散，奥氏体的马氏体起始温度被高估了。奥氏体晶粒尺寸受低温影响以及在临界退火期间铁素体的存在影响了最佳淬火温度。提出并验证了考虑各种合金元素扩散和奥氏体晶粒尺寸的方案。使用该方案，可以很好地预测具有复杂组织的临界退火退火和分区钢的最佳淬火温度。