摘要
采用药芯焊丝气体保护堆焊方法制备Fe-Cr-B-C堆焊合金,利用金相、SEM、XRD等方法,分析了不同硼含量对堆焊合金组织及硼化物形貌的影响。结果表明:Fe-12Cr-xB-0.1C合金的显微组织由铁素体+奥氏体+(Fe,Cr)2B+(Fe,Cr)23(B,C)6组成。当硼含量<3%(质量分数,下同)时,随着硼含量增加,硼化物形态逐渐由断续网状转变为网状;当硼含量≥3%时,随着硼含量增加,初生块状(Fe,Cr)2B数量逐渐增加,其尺寸和分布更均匀,硼化物主要呈块状、条状、鱼骨状、蜂窝状及菊花状分布。初晶(Fe,Cr)2B近似呈四边形柱状体,趋向垂直于堆焊层表面生长。当硼含量≤4%时,硼的增加能显著提高Fe-Cr-B-C堆焊合金的硬度及耐磨性。
Fe-Cr-B-C hardfacing alloys were deposited by flux-cored wire using metal active gas arc welding(MAG).The effect of boron contents on the microstructures and boride morphologies of the hardfacing alloys was analyzed by optical microscopy(OM),scanning electron microscopy(SEM)and X-ray diffraction(XRD).The results indicate that the microstructures of Fe-12Cr-xB-0.1Calloys consist of ferrite,austenite,(Fe,Cr)2B,and(Fe,Cr)23(B,C)6.The morphology of borides transforms from the discontinuous network to continuous network gradually with boron content increasing to 3%(mass fraction).As the boron content is higher than 3%,the amount of massive primary(Fe,Cr)2B increases with the increasing of boron contents.Meanwhile,the size and distributing of(Fe,Cr)2B become more homogeneous.The morphology of primary boride has many kinds of distribution shape,including massive,strip,fish-bone-like,honeycomb and chrysanthemum.The shape of the primary(Fe,Cr)2B is quadrangular column which tends to grow perpendicular to the overlayer surfaces.Increasing boron content can significantly improve the hardness and abrasive wear resistance of Fe-Cr-B-C hardfacing alloys when the boron content is lower than 4%.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2014年第9期57-62,共6页
Journal of Materials Engineering
基金
北京市教委科技成果转化与产业化项目(JP009012201401)
关键词
堆焊合金
显微组织
硼
硼化物
磨粒磨损
hardfacing alloy
microstructure
boron
boride
abrasive wear
