L. P. Xu
,
M. H. Xu
,
L. Li
,
Y.A. Min
,
X.Z Xuand R.H .Liu (Department of Materials Science and Engineering
,
Shanghai University
,
Shanghai 200072
,
China) (Shanghai No.5 Iron and Steel Factory
,
Shanghai 200940
,
China)
金属学报(英文版)
The composition of a bearing steel was designed for limited hardenability by use of Grossmann's method. A medium frequency induction Process was applied to heat bearings to ensure penetrant heating and suitable solving of carbon and other elements in the matrix. The hardened depth measured from the end quenching test samples and actual bearings matches well with the designed one.
关键词:
: bearing steel
,
null
,
null
Q. Qu
,
C.W. Yan
,
L. Li
,
L. Zhang
,
G.H. Liu
,
C.N. Cao
金属学报(英文版)
Influence of NH4Cl on the initial atmospheric corrosion of zinc was investigated via
quartz crystal microbalance (QCM) in laboratory at 80%RH and 25℃. The results
show that NH4Cl can accelerate the initial corrosion of zinc. Mass gain increase with
the exposure time, but mass gain in the later doesn't change obviously due to the
formation of the insoluble simonkolleite on zinc surface in the presence of NH4Cl.
Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) was
used to characterize the corrosion products. Zn5Cl2(OH)8·H2O, (NH4)2ZnCl4 and
ZnO are the corrosion products on zinc. Brief discussion on the mechanisms of atmospheric corrosion of zinc in the presence of NH4Cl was introduced.
关键词:
atmospheric corrosion
,
null
,
null
X.C. Wei
,
L. Li
,
R.Y. Fu
金属学报(英文版)
Tensile mechanical properties of 1.6Si-1.58Mn-0.195C TRIP (transformation-inducedplasticity) steels under high strain rate and effects of DP (dual-phase) treatments werestudied and compared to the quasi-static tensile behavior. The results show that theincreasing of strain rate leads to increasing in their strengths and decreasing in theuniform elongation remarkably. Because the stable retained austenite in TRIP steelcan transform to martensite during tensile testing and the material exhibits excellentcharacteristic of transformation induced plasticity, the plastic deformation behavior isevidently improved and the combination of strength and elongation is superior to thatof dual-phase steel, although its strength is smaller than that of DP steel. However,DP treated steel shown lower elongation under dynamic tension in spite of higherstrength. A model was proposed to explain the excellent elongation rate of TRIPsteel compared with DP steel on the basis of SEM analysis and the strength of thecomponents in microstructure.
关键词:
automobile sheet steel
,
null
,
null
,
null
