CAJ | 학술논문

目的：研制一种新型添加纳米Y2 O3的过共晶Fe-Cr-C 堆焊合金,改善堆焊合金粗大的初生M7 C3碳化物,提高堆焊合金的耐磨性。方法采用明弧堆焊的方法制作堆焊合金,用金相电子显微镜对其表面微观组织进行观察,用洛氏硬度计对其表面硬度进行测量,用砂带摩擦磨损试验机对其表面耐磨性进行评价,用扫描电子显微镜对其磨损形貌进行观察。最后,利用错配度理论对M7 C3的细化机理进行分析。结果过共晶Fe-Cr-C堆焊合金由初生M7 C3和共晶组织(共晶M7 C3、奥氏体及部分马氏体)组成。未添加Y2 O3的堆焊合金初生M7 C3比较粗大,其平均尺寸在22μm,硬度为55HRC,磨损量为0.85 mg/mm2。经纳米Y2 O3改性之后,堆焊合金的初生 M7 C3尺寸变小,其平均尺寸为16μm,硬度为57HRC,磨损量减少为0.59 mg/mm2,Y2O3的(001)面与正交 M7C3的(100)面之间的二维错配度为8.59%。结论 Y2 O3可以成为M7 C3的非均质形核核心,从而细化了过共晶Fe-Cr-C 堆焊合金的初生M7 C3碳化物,提高了过共晶Fe-Cr-C堆焊合金表面耐磨性。
목적：연제일충신형첨가납미Y2 O3적과공정Fe-Cr-C 퇴한합금,개선퇴한합금조대적초생M7 C3탄화물,제고퇴한합금적내마성。방법채용명호퇴한적방법제작퇴한합금,용금상전자현미경대기표면미관조직진행관찰,용락씨경도계대기표면경도진행측량,용사대마찰마손시험궤대기표면내마성진행평개,용소묘전자현미경대기마손형모진행관찰。최후,이용착배도이론대M7 C3적세화궤리진행분석。결과과공정Fe-Cr-C퇴한합금유초생M7 C3화공정조직(공정M7 C3、오씨체급부분마씨체)조성。미첨가Y2 O3적퇴한합금초생M7 C3비교조대,기평균척촌재22μm,경도위55HRC,마손량위0.85 mg/mm2。경납미Y2 O3개성지후,퇴한합금적초생 M7 C3척촌변소,기평균척촌위16μm,경도위57HRC,마손량감소위0.59 mg/mm2,Y2O3적(001)면여정교 M7C3적(100)면지간적이유착배도위8.59%。결론 Y2 O3가이성위M7 C3적비균질형핵핵심,종이세화료과공정Fe-Cr-C 퇴한합금적초생M7 C3탄화물,제고료과공정Fe-Cr-C퇴한합금표면내마성。
ABSTRACT:Objective To develop novel hypereutectic Fe-Cr-C hardfacing alloys ( Y2 O3-free and Y2 O3-modified, respectively) <br> so as to improve the coarse carbides and increase the wear resistance of Fe-Cr-C hardfacing alloys. Methods The hardfacing alloys were deposited by the automatic open arc surfacing welding method. The microstructures were observed by optical microscopy. Meanwhile, the macro hardness of the hardfacing alloy surface was measured by the Rockwell hardness tester. The wear resistance of the hardfacing alloy surface was evaluated by the abrasive wear test. Worn morphology was observed by field emission scanning electron microscopy. Moreover, the mechanism of the microstructure refinement by the two-dimensional misfit theory was also dis-cussed. Results The results showed that the microstructures of the hardfacing alloy consisted of the primary M7 C3( M=Cr, Fe) car-bide and eutectic structure ( eutectic M7 C3 carbide+retained austenite and its product) . The average size of primary carbide was a-bout 22 μm. The mass loss and the hardness of the Y2 O3-free alloy were 0. 85 mg/mm2 and 55HRC, respectively. After adding Y2 O3 , the average size of carbide was about 16μm. The mass loss of the coating was 0. 59 mg/mm2 and the hardness was 57HRC. The two-dimensional lattice misfit between the face (001) of Y2 O3 and the face (100) of orthorhombic M7 C3 was 8. 59%. Con-clusion By adding Y2 O3 as the heterogeneous nuclei, the primary M7 C3 carbide was refined and the wear resistance of the hypereu-tectic Fe-Cr-C hardfacing alloy surface can be improved.