热处理对复合制造AerMet100超高强度钢组织均匀性与拉伸性能的影响

Microstructure homogeneity of the hybrid fabricated AerMet100 steel under different heat treatment processes was studied, room temperature tensile properties of the specimens were tested, and the fracture mechanism was analyzed. The results show that microstructure of the as-deposited hybrid fabricated AerMet100 steel is very inhomogeneous, and the specimen contains laser deposited zone, forged zone, heat affected zone of the forged plate. After standard heat treatment commonly used for forged part, columnar grains transform to equiaxed grains for the laser deposited zone, and microstructure of all the three zones as mentioned above is the similar tempered martensite. However, the element segregation in the laser deposited zone is still observed. After homogeneity heat treatment at 1200 ℃ before heat treatment, microstructure of the hybrid fabricated AerMet100 steel becomes very homogeneous, the element segregation in the laser deposited zone is basically eliminated. the room temperature tensile properties are the best which are comparable with the forged zone, and the corresponding tensile specimen indicates ductile fracture mechanism, of which fracture occurs in the laser deposited zone.