外场处理细化管线钢埋弧焊缝的显微组织

研究了电磁搅拌和氩弧表层快速加热等外场对管线钢埋弧焊缝显微组织的影响。结果表明，电磁搅拌改变了焊缝中非金属杂夹物的大小和尺寸分布，使尺寸位于0.2～0.6μm之间的夹杂物数量增加，促进了奥氏体晶粒内针状铁素体的生成和细化，针状铁素体的含量由85.1%提高到了91.7%，提高了熔敷金属的韧性。而氩弧加热处理使焊缝表层的柱状晶消失，针状铁素体晶粒明显细化，并消除了对性能有害的组织-晶界铁素体和侧板条铁素体。

External Field Treatment Refining Microstructures of Pipe-line Steel SAW Weld

The effects of electromagnetic stirring and TIG surface treat process on the microstructures of pipe-line steel SAW deposited metals were investigated.The results showed that electromagnetic stirring changed the size and distribution of inclusions in deposited metals,increased the density of inclusions with 0.2～0.6μm diameter,promoted the formation and refining of acicular ferrite within austenite gains.The contents of AF within austenite gains were increased from 85.1% to 91.7% and the low temperature toughness of deposited metal was improved.TIG surface treat process eliminated column gain structures of surface layer of welds.The size of acicular ferrite was greatly refined and grain boundary ferrite and side-plate ferrite disappeared.