Co 添加对新型海工焊材中碳化物析出的影响

Effect of adding 6% Co to a novel marine welding material on the precipitation of different types of carbides was systematically analyzed by using the thermodynamics calculation software Thermo-Calc and TC-Prisma. The results show that the addition of 6% Co significantly increases the phase transformation temperature from FCC to BCC,elevates the precipitation temperatures of MC-type and HCP-type carbides,while reducing the precipitation temperature and precipitation amount of Cu-rich precipitates. Specifically,6% Co remarkably promotes the nucleation rate of M₆C,HCP,and MC carbides,with a more prominent effect on HCP and M₆C carbides. The addition of 6% Co increases the precipitation number density of M₆C and HCP carbides,but significantly inhibits the precipitation quantity of MC carbides. By altering the diffusion coefficient of carbon atoms,the addition of 6% Co restricts the growth rate of carbides,resulting in a reduction in the size of three types of precipitated carbides. The effect of Co addition on the precipitation volume fraction of three types of carbides varies significantly. The precipitation volume fraction of HCP carbides firstly has little effect and then decreases,while the volume fraction of M₆C increases to a stable level (2. 2%),and the volume fraction of MC carbides significantly decreases.