GRAIN COARSENING BEHAVIOR OF V-Ti-N MICROALLOYED STEELS

摘要

The effects of chemical composition and cooling rate after solidication on the grain coarseningtemperature,T_GC,of the V-Ti-N microalloyed steels have been investigated.It is shownthat the T_GC may be obviously raised by adding even a little Ti to the base steel so as to pre-cipitate a great deal of fine Ti-bearing particles of about 10 nm.The T_GC does not increasewith the cooling rate,as it is over a certain critical value.The T_GC is insensitive to any varia-tion of N content at simulated cooling condition of 150 mm continuous cast slab.TheT_GC may be dropped down about 100℃ by adding 0.33 wt-%Mo to the steels.The sensitivi-ty of T_GC to cooling condition relates to the Ti and V contents.