【摘要】 自由锻造的X19CrMoVNbN11-1方钢油淬后发生开裂。为此，检测开裂方钢的化学成分、碳化物形态、冲击断口形貌，研究其淬火方式、装载量、轧制和锻造工艺对X19CrMoVNbN11-1钢力学性能的影响；此外，对比国产和进口方钢的化学成分、显微组织和力学性能差异。结果表明：X19CrMoVNbN11-1方钢淬火开裂的主要原因是原材料采用单一的轧制方式，使得方钢锻造不充分，显微组织不够致密且有微裂纹；另外，方钢的微米级碳化物呈带状分布，易产生应力集中。更多还原

【Abstract】 Free forged X19CrMoVNbN11-1 square steels were found cracking after being quenched in oil. The cracked square steel was tested for chemical composition, form of carbides and pattern of impact fracture. The effect of quenching procedures, loading capacity, rolling and forging processes on mechanical properties of X19CrMoVNbN11-1 steel was investigated. The differences between domestic and imported square steels in chemical composition, microstructure and mechanical properties were compared.The results showed that the main causes for cracking of X19CrMoVNbN11-1 square steels during quenching proved to be as follows: the raw material was formed by a single rolling way, the square steel did be sufficiently forged, thus resulting in insufficiently dense microstructure and presence of fine cracks, and the micro-level carbides were in banding form, therefore the stress concentration was easy to develop.更多还原