Luming MA
,
Guojun LIANG
,
Jun TAN
,
Lijian RONG
,
Yiyi LI
材料科学技术（英文）
The method of high-pressure hydrogen charging was used to investigate the internal hydrogen effects on cryogenic mechanical properties of two Cr-Ni-Mn-N austenitic steels, 22-13-5 and 21-6-9. Specimens saturated with hydrogen up to 65×10-6~68×10-6were tested in air at temperatures ranging from 77 to 293 K. Hydrogen caused the increase in cryogenic strength, both yield strength and ultimate tensile strength. Hydrogen decreased cryogenic ductility, and the maximum hydrogen embrittlement (HE) tendency was found at a certain low temperature. Cr-Ni-Mn-N austenitic steels showed the feature: δL>ΨL at low temperatures, here, δL andΨL are the hydrogen induced loss rates of elongation and reduction of area, respectively. Hydrogen had less effect on cryogenic Charpy impact toughness and notched tensile strength, however, hydrogen decreased cryogenic fracture toughness of the steels. At temperature below Md, the fracture toughness was obviously decreased due to the formation of strain-induced martensites, whether hydrogen was charged or not.
关键词:
Bin ZHANG
,
Qingyuan YU
,
Jun TAN
,
Guangping ZHANG
材料科学技术（英文）
200-nm-thick Au interconnects on a quartz substrate were tested in-situ inside a dual-beam microscope by applying direct current, alternating current and alternating current with a small direct current component. The failure behavior of the Au interconnects under three kinds of electric currents were characterized in-situ by scanning electron microscopy. It is found that the formation of voids and subsequent growth perpendicular to the interconnect direction is the fatal failure mode for all the Au interconnects under three kinds of electric currents. The failure mechanism of the ultrathin metal lines induced by the electric currents was analyzed.
关键词:
Au interconnect
,
null
,
null
,
null
Ye WAN
,
Chuanwei YAN
,
Chunan CAO
,
Jun TAN
材料科学技术（英文）
A laboratory study of the atmospheric corrosion of carbon steel deposited with (NH4)2SO4 in the presence of SO2 is reported. The different levels of (NH4)2SO4 (0, 15, 30, 45, 60μg·cm2 were added on the surface of the samples before the exposure. The corrosion was investigated by a combination of gravimetry, Fourier transform infrared spectroscope and scanning electron microscopy. A detailed knowledge about the corrosion products was acquired, both quantitatively and qualitatively. The results show that the metal loss increased and the increasing tendency of corrosion rates slowed down with the increasing exposure time. The phase constituents of the corrosion products are mainly α-FeO(OH), γ-FeO(OH), and δ-FeO(OH).
关键词:
Steel A3
,
null
,
null
,
null
,
null
