摘要
采用爆炸喷涂技术在38CrMoAl钢表面制备了Cr3C2-25NiCr涂层,并在700、800及900℃下分别对其进行了热震试验,利用扫描电镜(SEM)、X射线衍射仪(XRD)、摩擦磨损试验机、电化学工作站等手段研究了涂层的高温氧化行为及耐腐蚀性能。结果表明:经过热震试验后,涂层中Cr3C2相逐渐被氧化脱碳成Cr7C3相,NiCr固溶相消失,转化为Cr3Ni2相以及NiCr2O4相,并出现了Cr5O12相,并且涂层因为高温氧化而出现了凹坑、微裂纹等。涂层中因氧化而产生的硬脆颗粒以及微裂纹会导致涂层的耐磨性能明显下降,破碎剥落的颗粒会成为新的磨料加剧磨损,并且涂层中能起到钝化耐腐蚀作用的Cr-O相消失,脆性破裂剥落的孔洞及微裂纹不断增加,会导致涂层的耐腐蚀性能随着热震温度的升高而逐渐降低。在700℃时,Cr3C2-25NiCr涂层具有良好的抗热震性能,随着热震温度进一步提高涂层的氧化行为加剧,抗热震及耐磨性能等明显降低。
Cr3C2-25 NiCr coating was prepared on 38 CrMoAl steel surface by detonation spraying technology,and thermal shock tests of the coating were carried out at 700,800 and 900℃,respectively.High temperature oxidation behavior and corrosion resistance of the coating were studied by means of scanning electron microscopy(SEM),X-ray diffractometer(XRD),friction and wear testing machine and electrochemical workstation.The results show that after thermal shock test,the Cr3C2 phase in the coating is gradually oxidized and decarbonized into Cr7C3 phase,the NiCr solid solution phase disappears and transforms into the Cr3Ni2 phase and NiCr2O4 phase,and the Cr5O12 phase appears,and the coating appears pits and microcracks due to high temperature oxidation.Hard and brittle particles and microcracks produced by oxidation in the coating will cause the wear resistance of the coating to decrease obviously,the broken and exfoliated particles will become new abrasive to aggravate the wear,and the Cr-O phase which can passivate and resist corrosion in the coating will disappear,and the pores and microcracks of brittle fracture and exfoliation will increase continuously,which will lead to the corrosion resistance of the coating gradually decrease with the increase of thermal shock temperature.The Cr3C2-25 NiCr coating has good thermal shock resistance at 700℃.With the increase of thermal shock temperature,the oxidation degree of the coating increases,the thermal shock resistance and wear resistance decrease obviously.
作者
赵坚
刘伟
陈小明
毛鹏展
伏利
张磊
无
ZHAO Jian;LIU Wei;CHEN Xiao-ming;MAO Peng-zhan;FU Li;ZHANG Lei;无(Standard&Quality Control Research Institute,Hangzhou 310012,China;State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China;Hangzhou Mechanical Research Institute,Hangzhou 310012,China;Key Laboratory of Surface Engineering of Equipments for Hydraulic Engineering of Zhejiang Province,Hangzhou 310012,China;Hydraulic Machinery and Remanufacturing Technology Engineering Laboratory of Zhejiang Province,Hangzhou 310012,China)
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2020年第12期112-118,共7页
Transactions of Materials and Heat Treatment
基金
浙江省科技计划项目(2018C37029)
浙江省科技计划项目(2019C04019)
浙江省科技计划项目(GC19E090001)
浙江省科技计划项目(2018C37029)。
