夹杂物对微合金钢熔敷金属针状铁素体形核的影响

Effects of nonmetallic inclusions on acicular ferrite nucleation in deposited metals of microalloyed steel

摘要: 研究了微合金钢熔敷金属中夹杂物大小、尺寸分布和化学成分对针状铁素体形核的影响。结果表明,作为针状铁素体形核核心的夹杂物,其尺寸大多数位于0.2~0.6 μm之间,并且是含有多种元素的复合夹杂物,具有化学成分不均匀的性质。夹杂物作为一种高能的惰性表面,降低了形核能垒,促进了针状铁素体的形核。当一个针状铁素体以夹杂物为初始核心先期形核后,又可诱发大量的相互交错的针状铁素体感应形核。

Abstract: The effects of the size, distribution and chemical composition of inclusions on nucleation of acicular ferrite in deposited metals of micro-alloyed steel were studied.The results show that the inclusions as nuclei of acicular ferrite are chemical heterogeneous compounds containing various elements.Most of them are within 0.2-0.6 μm in diameter.The inclusions reduce the energy barrier to nucleation by acting as high-energy inert substrates, promoting the nucleation of acicular ferrite.The primary acicular ferrite plates initially nucleate at intragranular inclusions and then many fine interlocked acicular ferrite grains nucleate sympathetically and grow from the primary plates.