The Ni-Fe based superalloy GH984 with microalloying is fabricated by vacuum induction furnace and hot worked by hot forging and rolling. The effect of B and P microalloying on microstructure and mechanical properties of GH984 alloy was investigated by OM, SEM and TEM after standard heat treatment. The experiment results showed that the addition of B and P has no obvious effects on the microstructure of GH984 alloy which has precipitates of sphericalγ', Ti(C, N), blocky MC as well as discrete M23C6 distributing along grain boundary. Moreover, the addition of B and P has no obvious influence on the tensile strength at room temperature and 700℃. However, tensile ductility increases greatly at 700 ℃ after B and P doping. It is worth to note that B and P microslloying can improve the stress rupture life of the alloy significantly. For example, the rupture life at the condition of 700 ℃ and 350 MPa increases from initial 115.03 h to 984.15 h. Investigation on the microstucture of the creep samples exhibites that B and P could effectively improve the strength of grain boundary and the fractural model from intergranular fracture to intergranular/transgranular mixed fracture.
肖旋,赵海强,王常帅,郭永安,郭建亭,周兰章. B和P对GH984合金组织和力学性能的影响[J]. 金属学报, 2013, 29(4): 421-427.
XIAO Xuan, ZHAO Haiqiang, WANG Changshuai, GUO Yongan, GUO Jianting,ZHOU Lanzhang. EFFECTS OF B AND P ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF GH984 ALLOY. Acta Metall Sin, 2013, 29(4): 421-427.