The present work attributes the role of boron on the high strength steel submerged arc weld using an undermatching filler wire.Mild steel filler wire was used for welding in constant machine parameters setting to eval...The present work attributes the role of boron on the high strength steel submerged arc weld using an undermatching filler wire.Mild steel filler wire was used for welding in constant machine parameters setting to evaluate the joint strength due to the enrichment of boron.To change the chemical composition of the weld metal,boron trioxide powder was blended with virgin flux in various proportions(2.5%−12.5%),which led to an increase in boron weight percentage in the range of 0−0.0065.The results show that weld metals(WM)optical micrographs depict the various types of ferrites,pearlites and secondary phases like martensite-austenite(M-A).Acicular ferrite content was influenced by the boron trioxide addition.Heat affected zone(HAZ)micrographs were not showing appreciable changes with oxide enrichment.Hardness and toughness of weld metals showed the mixed trend with B_(2)O_(3) enrichment whereas,small reduction in ultimate tensile strength(UTS)and yield strength(YS)was observed.展开更多
B_(2)O_(3)-Zn O-SiO_(2)(BZS)glass containing Cu O with excellent acid resistance,wetting properties,and high-temperature sintering density was prepared by high temperature melting method and then applied in copper ter...B_(2)O_(3)-Zn O-SiO_(2)(BZS)glass containing Cu O with excellent acid resistance,wetting properties,and high-temperature sintering density was prepared by high temperature melting method and then applied in copper terminal electrode for multilayer ceramic capacitors(MLCC)applications.The structure and property characterization of B_(2)O_(3)-Zn O-SiO_(2)glass,including X-ray diffraction,FTIR,scanning electron microscopy,high-temperature microscopy,and differential scanning calorimetry,indicated that the addition of CuO improved the glass’s acid resistance and glass-forming ability.The wettability and acid resistance of this glass were found to be excellent when CuO content was 1.50 wt%.Compared to BZS glass,the CuO-added glass exhibited excellent wettability to copper powder and corrosion resistance to the plating solution.The sintered copper electrode films prepared using the glass with CuO addition had better densification and lower sintering temperature of 750℃.Further analysis of the sintering mechanism reveals that the flowability and wettability of the glass significantly impact the sintering densification of the copper terminal electrodes.展开更多
Fluid catalytic cracking(FCC)is still a key process in the modern refining industry,in which nickel contamination of the FCC catalyst can significantly increase the dry gas and coke yields and thus seriously affect th...Fluid catalytic cracking(FCC)is still a key process in the modern refining industry,in which nickel contamination of the FCC catalyst can significantly increase the dry gas and coke yields and thus seriously affect the stability of the FCC unit.Therefore,in this work,B_(2)O_(3)-modified SBA-15 molecular sieves(B_(2)O_(3)/SBA-15)with different B_(2)O_(3) contents were prepared,characterized,and further used as matrix component in the preparation of Ni-tolerant FCC catalyst.The characterization results indicated that the B_(2)O_(3)/SBA-15 samples possessed excellent Ni passivation ability and kept the characteristic structure of the parent SBA-15 such as highly ordered mesopores,large surface area,and high pore volume,which enabled the B_(2)O_(3)/SBA-15 sample to greatly improve the Ni tolerance of the prepared FCC catalyst.The heavy oil catalytic cracking tests indicated that,under the same Ni contamination conditions,the dry gas,coke,and heavy oil yields of the FCC catalyst containing B_(2)O_(3)/SBA-15 decreased by 0.92%,1.65%,and 1.26%,respectively,compared with those of conventional FCC catalyst,while the total liquid yield increased by 3.83%.展开更多
文摘The present work attributes the role of boron on the high strength steel submerged arc weld using an undermatching filler wire.Mild steel filler wire was used for welding in constant machine parameters setting to evaluate the joint strength due to the enrichment of boron.To change the chemical composition of the weld metal,boron trioxide powder was blended with virgin flux in various proportions(2.5%−12.5%),which led to an increase in boron weight percentage in the range of 0−0.0065.The results show that weld metals(WM)optical micrographs depict the various types of ferrites,pearlites and secondary phases like martensite-austenite(M-A).Acicular ferrite content was influenced by the boron trioxide addition.Heat affected zone(HAZ)micrographs were not showing appreciable changes with oxide enrichment.Hardness and toughness of weld metals showed the mixed trend with B_(2)O_(3) enrichment whereas,small reduction in ultimate tensile strength(UTS)and yield strength(YS)was observed.
基金the National Natural Science Foundation of China(Nos.51372179,51772224)the Open Project Foundation of Guangdong Fenghua Advanced Technology(No.FHR-JS-202011024)。
文摘B_(2)O_(3)-Zn O-SiO_(2)(BZS)glass containing Cu O with excellent acid resistance,wetting properties,and high-temperature sintering density was prepared by high temperature melting method and then applied in copper terminal electrode for multilayer ceramic capacitors(MLCC)applications.The structure and property characterization of B_(2)O_(3)-Zn O-SiO_(2)glass,including X-ray diffraction,FTIR,scanning electron microscopy,high-temperature microscopy,and differential scanning calorimetry,indicated that the addition of CuO improved the glass’s acid resistance and glass-forming ability.The wettability and acid resistance of this glass were found to be excellent when CuO content was 1.50 wt%.Compared to BZS glass,the CuO-added glass exhibited excellent wettability to copper powder and corrosion resistance to the plating solution.The sintered copper electrode films prepared using the glass with CuO addition had better densification and lower sintering temperature of 750℃.Further analysis of the sintering mechanism reveals that the flowability and wettability of the glass significantly impact the sintering densification of the copper terminal electrodes.
基金National Natural Science Foundation of China(grant number:21902008)Doctor Research Program of Shandong University of Technology(No.4041/420117).
文摘Fluid catalytic cracking(FCC)is still a key process in the modern refining industry,in which nickel contamination of the FCC catalyst can significantly increase the dry gas and coke yields and thus seriously affect the stability of the FCC unit.Therefore,in this work,B_(2)O_(3)-modified SBA-15 molecular sieves(B_(2)O_(3)/SBA-15)with different B_(2)O_(3) contents were prepared,characterized,and further used as matrix component in the preparation of Ni-tolerant FCC catalyst.The characterization results indicated that the B_(2)O_(3)/SBA-15 samples possessed excellent Ni passivation ability and kept the characteristic structure of the parent SBA-15 such as highly ordered mesopores,large surface area,and high pore volume,which enabled the B_(2)O_(3)/SBA-15 sample to greatly improve the Ni tolerance of the prepared FCC catalyst.The heavy oil catalytic cracking tests indicated that,under the same Ni contamination conditions,the dry gas,coke,and heavy oil yields of the FCC catalyst containing B_(2)O_(3)/SBA-15 decreased by 0.92%,1.65%,and 1.26%,respectively,compared with those of conventional FCC catalyst,while the total liquid yield increased by 3.83%.
