Observation of nucleation and growth of acicular ferrite in HSLA steel weld-metal

摘要

Heterogeneous nucleation and growth of acicular ferrite in HSLA steel weld-metal were in-situ observed by using laser scanning confocal microscopy. The applied thermal cycle simulated cooling rate of large heat-input welding. The high time-resolved images made for heterogeneous nucleation at inclusion and hard impingement between ferrite plates to be clear. Furthermore, the crystal orientation relationships between observed substrate for the heterogeneous nucleation and nucleated solid were analyzed.