Abstract：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-0.1C alloys 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%.
王智慧, 万国力, 贺定勇, 蒋建敏, 崔丽. Fe-Cr-B-C堆焊合金的组织与耐磨性[J]. 材料工程, 2014, 0(9): 57-62.
WANG Zhi-hui, WAN Guo-li, HE Ding-yong, JIANG Jian-min, CUI Li. Microstructures and Wear Resistance of Fe-Cr-B-C Hardfacing Alloys. Journal of Materials Engineering, 2014, 0(9): 57-62.
BUCHELY M F, GUTIERREZ J C, LE'ON L M, et al. The effect of microstructure on abrasive wear of hardfacing alloys[J]. Wear, 2005, 259(1-6): 52-61.
WANG Z H, WANG Q B, CUI L. Influence of cooling rate and composition on orientation of primary carbides of Fe-Cr-C hardfacing alloys[J]. Science and Technology of Welding and Joining, 2008, 13(7): 656-672.
LU L M, SODA H, MCLEAN A. Microstructure and mechanical properties of Fe-Cr-C eutectic composites[J]. Materials Science and Engineering: A, 2003, 347(1):214-222.
KIM J H, HONG H S, KIM S J. Effect of boron addition on the cavitation erosion resistance of Fe-based hardfacing alloy[J]. Materials Letters, 2007, 61(4-5): 1235-1237.
DWIVEDI D K. Microstructure and abrasive wear behaviour of iron base hardfacing[J]. Materials Science and Technology, 2004, 20(10):1326-1330.
王智慧,贺定勇,王月琴. 硼对Fe-Cr-C耐磨堆焊合金组织的影响[J]. 材料工程, 2001,(10): 18-20.WANG Zhi-hui, HE Ding-yong, WANG Yue-qin. Influence of boron contents on the microstructures of Fe-Cr-C hardfacing alloy [J]. Journal of Materials Engineering, 2001, (10): 18-20.
SCANDELLA F, SCANDELLA R. Development of hardfacing material in Fe-Cr-Nb-C system for use under highly abrasive conditions[J]. Materials Science and Technology, 2004, 20(2):93-105.
叶荣昌, 葛长路. 硼对堆焊合金组织与性能的影响[J]. 热加工工艺, 1998, (3): 19-20.YE Rong-chang, GE Chang-lu. The influence of boron on the microstructure and properties of the surfaced alloy[J].Hot Working Technology, 1998, (3): 19-20.
LIU Z L, CHEN X, LI Y X, et al. High boron iron-based alloy and its modification[J]. Journal of Iron and Steel Research International,2009, 16(3): 37-42.
龚建勋, 李丹, 肖逸锋,等. Fe-Cr-B-C 堆焊合金的显微组织及耐磨性[J]. 材料热处理学报, 2010, 31(3): 18-20. GONG Jian-xun, LI Dan, XIAO Yi-feng, et al. Microstructure and wear resistance of Fe-Cr-B-C hardfacing alloys[J].Transactions of Materials and Heat Treatment,2010, 31(3): 18-20.
GUO C Q, KELLY P M. Boron solubility in Fe-Cr-B cast irons[J]. Materials Science and Engineering: A, 2003, 352(1-2): 40-45.
BERNS H, FISCHER A. Microstructure of Fe-Cr-C hardfacing alloys with additions of Nb, Ti and B[J]. Materials Characterization, 1997, 39(2): 499-527.
FAN C, CHEN M C, CHANG C M, et al. Microstructure change caused by (Cr,Fe)23C6 carbides in high chromium Fe-Cr-C hardfacing alloys[J]. Surface & Coatings Technology, 2006, 201(3-4):908-912.
KIM J H, KO K H, NOH S D, et al. The effect of boron on the abrasive wear behavior of austenitic Fe-based hardfacing alloys [J]. Wear, 2009, 267(9):1415-1419.
JANKANSKAS V, KREIVAITIS R, MILCIUS D, et al. Analysis of abrasive wear performance of arc welded hard layers[J]. Wear, 2008, 265 (11-12):1026-1032.