Effects of inclusions on microstructure and properties of heat-affected-zone for low-carbon steels  

作　　者：ZHENG ChaoChao WANG XueMin LI ShuRui SHANG ChengJia HE XinLai 

机构地区：[1]School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China [2]Wuhan Iron and Steel(Group)Corp.,Wuhan 430080,China

出　　处：《Science China(Technological Sciences)》2012年第6期1556-1565,共10页中国科学（技术科学英文版）

基　　金：supported by the National Basic Research Program of China ("973" Program) (Grant No. 2010CB630801)

摘　　要：The characteristics of inclusions in two types of low-carbon steels by different deoxidization methods have been investigated by using the welding thermal simulation, the optical microscopy and scanning electron microscopy. In addition, the effects of inclusions on microstructure and properties of heat-affected-zone were studied. The nucleation and growth of intragranular acicular ferrite was observed in situ by the laser scanning confocal microscopy. The distribution of Mn element near the inclu- sion was also analyzed by the auger electron spectroscopy. The results showed that the inclusions in A1 killed steel are mainly aluminum oxides, manganese sulfide and titanium nitrides, and that the inclusions in Ti killed steel are mainly titanium oxide, manganese sulfide complex inclusion and single manganese sulfide. The auger electron spectroscopy showed that there is an Mn-depleted zone near the interface of TiOffMnS complex inclusion in the size of 1-3 gm. It could be the effective nucleus of intragranular acicular ferrite which could divide the prior austenite grains, inhibit the growth of low-temperature microstruc- ture, and refine the final microstructure, so as to improve the toughness of heat-affected-zone significantly.

关 键 词：low-carbon steel INCLUSION intragranular acicular ferrite heat-affected-zone 

分 类 号：TG142.41[一般工业技术—材料科学与工程] TG161.8[金属学及工艺—金属材料]