L415/IN825复合板焊接接头渗硼处理工艺及渗层的组织与性能

Boronizing Process of Welding Joints of L415/IN825 Composite Plates and Microstructure and Properties of Boronized Layer

目前对双金属复合板焊接接头的渗硼处理鲜有研究报道。为了提高双金属复合板焊接接头的耐蚀和耐磨性能,对其表面进行渗硼处理。采用光学显微镜(OM)、扫描电镜(SEM)、X射线衍射仪(XRD)及显微硬度计分别对L415/IN825复合板复层焊接接头渗层的微观组织、物相组成及显微硬度进行了分析,并研究了复合板焊接接头及其渗层电化学腐蚀性能。结果表明:复合板焊接接头复层渗层分为硼化物层(Ni_2B、Cr_5B_3、Cr_2B和CrB)和硅化物层(Ni_2Si、Cr_3Ni_2Si和Cr_(13)Ni_5Si_2),全渗层的厚度随着加热温度和保温时间的增加而增加;不同区域渗层表面的显微硬度值均高于基体;复合板焊接接头基体耐蚀性能优于焊接接头表面渗层。

Boronizing treatment was conducted on bi-metal composite plates welding joint to improve the corrosion resistance and wear resistance.The microstructure and phase of the boronized clad layer welding joint of L415/IN825 composite plates were characterized by optical microscope （OM）,scanning electron microscope （SEM） and X-ray diffractometer （XRD）.The micro-hardness of the boronized welding joint was studied by the micro-hardness tester.The corrosion resistance of the boronized welding joint was tested by electrochemical workstation.Results showed that the surface of the boronized welding joint contained botide phases （Ni2B,Cr2B3,Cr2B and CrB） and silicide phases （Ni2 Si,Cr3Ni2 Si and Cr13Ni5Si2）.The thickness of coating increased with extending of boronizing time and increase of temperature.The micro-hardness of the coatings in different areas was much higher than that of the substrate.Besides,the unboronized sample possessed better corrosion resistance than the boronized coatings.