Nucleation of intragranular ferrite at Ti2O3 particle in low carbon steel

✍ Scribed by J.-H Shim; Y.W Cho; S.H Chung; J.-D Shim; D.N Lee

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 367 KB
• Volume: 47
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/s1359-6454(99)00114-7

✦ Synopsis

AbstractÐSystematic experiments have been performed to study the intragranular nucleation phenomena of ferrite in Ti-bearing low carbon steels. The ®ne intragranular acicular ferrite structure in Ti-bearing low carbon steels is induced by heterogeneous nucleation of ferrite plates at ®ne dispersed Ti 2 O 3 particles, which are thermodynamically stable in the steels. From a steel±Ti 2 O 3 diusion bonding experiment, it is clearly observed that a local Mn-depleted zone (MDZ) has developed in the vicinity of the steel±Ti 2 O 3 interface. The MDZ formation around Ti 2 O 3 particles is believed to be a dominant driving force for the heterogeneous nucleation of intragranular ferrite. It is also con®rmed that the development of the MDZ is associated with the absorption of Mn into the Ti 2 O 3 phase at high temperatures. The width of the MDZ decreases with decreasing bonding (austenitizing) temperature and in¯uences greatly the intragranular nucleation ability of acicular ferrite at Ti 2 O 3 particles.