FH690级超高强船板显微组织特征及其对低温韧性影响

Microstructure Characteristics of FH690 Ultra-strength Ship Structure Steel and Its Effects on Low Temperature Toughness

通过OM、SEM、TEM等手段研究了FH690级超高强船板钢的组织特征以及其对低温韧性的影响。结果表明:通过控制轧制与控制冷却获得板条贝氏体和少量粒状贝氏体的复合组织,该组织具有优良的力学性能,完全满足FH690级船用钢的标准。获得的细化板条状贝氏体组织及其内部高密度位错的亚结构是提高实验钢强度和低温韧性的保障。

The microstructure characteristics of FH690 ultra-strength ship structure steel and its effects on low temperature toughness were studied by OM,SEM and TEM.It is shown that the testing steel produced by TMCP possesses high strength and excellent low-temperature toughness,its microstructure is composed of lath bainite and a little granular bainite.It fully meets the standard of the FH690 type ship steel.There are high density of dislocations and substructures in the lath bainite,and these dislocations and substructures have a huge effect on improving the strength and low-temperature toughness of the testing steel.