Peng X.-Y.,Nanjing University of Aeronautics and Astronautics |
Peng X.-Y.,Nanchang Hangkong University |
Peng X.-Y.,Key Laboratory for Microstructural Control of Metallic Materials of Jiangxi Province |
Zhou X.-L.,Nanjing University of Aeronautics and Astronautics |
And 6 more authors.
Journal of Iron and Steel Research International | Year: 2015
Microstructure transformation and aging hardening behavior of 15-5 PH stainless steel were studied by optical microscopy (OM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the 15-5 PH stainless steel consists of NbC precipitates and lath matensite with a high dislocation density after solution treatment. With increasing aging temperature and aging time, the martensitic laths were resolved gradually. Meanwhile, the nanometric-sized Cu precipitates gradually coarsened and lost their coherency with the martensite matrix, which exhibited an elliptical shape finally. Fine Cu precipitates can lead to significant dispersion hardening effect, while the coarsened Cu precipitates have no contribution to strengthening. The reversed austenite was observed in the specimens aged at 550 °C and above; moreover, the amount of reversed austenite increased as aging temperature increased. The precipitation hardening behavior of 15-5 PH stainless steel may depend on the balance between the softening caused by the formation of reversed austenite and the hardening caused by the precipitation of copper. © 2015 Central Iron and Steel Research Institute.
Lv D.,Nanchang Hangkong University |
Lv D.,Key Laboratory for Microstructural Control of Metallic Materials of Jiangxi Province |
Ou J.,Nanchang Hangkong University |
Ou J.,Key Laboratory for Microstructural Control of Metallic Materials of Jiangxi Province |
And 4 more authors.
Applied Surface Science | Year: 2015
Superhydrophobic surface (SHS) was fabricated on aluminum via surface roughening by NaClO and surface passivation by hexadecyltrimethoxysilane. The long-term durability for storing the sample in air and the chemical stability for contacting the sample with NaCl solution were investigated. The short-term corrosion resistance for immersing the sample in NaCl solution for 1 h was investigated by potentiodynamic polarization, and the long-term corrosion resistance for immersing the sample in NaCl solution for 7 days was investigated by variation analyses on surface wettability, surface morphology, and surface chemistry. All experimental results suggested that the so-obtained SHS possessed good stability and good corrosion resistance under the testing conditions. © 2015 Elsevier B.V. All rights reserved.