X. Lu
,
Z.X. Qin
,
Y.S. Zhang
,
B.Z. Dine and Z.Q. Hu ( Department of Materials Science & Engineering
,
Dalian Railway Institute
,
Dalian 116028
,
China
,
State Key Laboratory for RSA
,
Institute of Metal Research
,
The Chinese Academy of Science
,
Shenyang 110015
,
China)
金属学报(英文版)
The stress-strain-resistance relations of the Fe-Mn-Si alloys with different Si content have been investigated by measuring strain (ε) and resistance (△ R/R) upon tension synchronously. The results show that the strum induced γ→ε martensitic transfor- mation increases the strain sensitivity coeffcient of resistance (K) for the Fe-Mn-Si alloys in plastic region. There is a critical strum where dσ/dε becomes a constant value. Si increases the critical strum. A correlation between the critical strain and shape memory effect (SME) in the Fe-Mn-Si alloys is suggested.
关键词:
stain inducedγ →ε martensitic transformation
,
null
,
null
W. P. Liu
,
F. X. Zhai and C. H. Ding (Dept. of Materials Science and Engineering
,
Dalian Railway Institute
,
Dalian 116028
,
China)
金属学报(英文版)
In this investigation, the Gleeble 1500 test simulator was used for carrying out experiments of joining by the pressurized combustion synthesis (PCS). The intermetallic compound Ni3Al was bonded by us- ing the exothermic synthesis reaction of a mixture of element Ni and Al poweders pre - compacted as the interlayer material.Effects of the key process parameters, such as the heating rate and joining tem- perature as well as the hold time, on the joint formation and microstructural homogeneity were studied. The feasibility of the addition of Al2O3 particles in the joint interlayer for producing intermetallic -ma- trix composite joints are also explored. Results show that the microstructrual homogeneity in the synthe- sized joint interlayer was significantly influenced by the joining process paramenters.The fully synthesized Ni2Al joints exhibited an average tensile strength of 486MPa at R. T. With the addition of Al2O3 ce- ramic particles in the reactants, joints with reighrced Ni3Al - matrix composite interlayer were ob- tained.
关键词:
combustion synthesis
,
null
,
null
F.Gao
,
B.Y.Song
,
H.F.Jiang and C.B.Jia Department of Material Science and Engineering
,
Dalian Railway Institute
,
Dalian 116028
,
China
金属学报(英文版)
The force feed lubrication method is used for drawing aluminum clad steel wire. It is studied how deformation of wire and aspect of the lubricant film are influenced by the die angle, the reduction, the drawing speed and the gap between pressure die and wire. It has been concluded that when the factors above mentioned promote to thicken lubricant film, the drawing force is reduced and this favors the homogenous deformation of aluminum coating and steel core.
关键词:
aluminum clad steel wire
,
null
,
null
F.Gao
,
B.Y.Song
,
C.B.Jia and Y.H.Wang Department of Material Science and Engineering
,
Dalian Railway Institute
,
Dalian 116028
,
China
金属学报(英文版)
In this study the process of cladding steel wires with aluminum is investigated experimentally. It is studied how the cladding process and the quality of products are influenced by the aluminum deformation temperature, the wheel speed, the temperature of steel wire, the wire speed and the steel wire tensile force. The relation among the process parameters above is discussed, and the effect of the aluminum deformation temperature on the coating microstructure is analyzed. This paper suggested a reasonable range of process parameters for producing aluminum cladding steel wires.
关键词:
aluminum cladding steel wire
,
null
,
null
Z.X Qinand Y.S. Zhang(Department of Materials Science and Engineering
,
Dalian Railway Institute
,
Dalian 116028
,
China)
金属学报(英文版)
The hyperfine interactions of two shape memory alloys have been studied by Mossbauer effect measurement at various temperatures. The Mossbauer spectra exhibit a mag-netic change from antiferro magnetic state to paramagnetic state when the temperuture rises. The Fe-Mn-Si alloys have a small hyperfine field and silicon element increases the hyperfine field and magnetic susceptibility. Thermo-induced γ→ ε trunsforma-tions are suppressed by Neel transition and by increasing carbon content, whereas stress induced γ→ ε transformation occurs in both alloys. Antiferromagnetic spin order can suppress thermo-induced γ→εtransformations efficiently, but cannot sup-press stress induced γ → ε transformation.
关键词:
phase transformation
,
null
,
null
,
null
CUI Juan
,
LIU Yazheng
,
PAN Hui
,
GAO Lifeng
钢铁研究学报(英文版)
The microsturctural transformation of austenite grain, pearlite interlamellar spacing, and lamellar cementite thickness of spring steel 60Si2MnA for railway were studied in the hotrolled and reheated states. Furthermore, the effect of microstructural characterization on its final mechanical properties was discussed. The results showed that as far as 60Si2MnA, the pearlite interlamellar spacing determined the hardness, whereas, the austenite grain determined the toughness. Compared with microstructure and mechanical properties in the hotrolled state, after reheating treatment at 950 ℃, its average grain sizes are apparently fine and the pearlite interlamellar spacing and lamellar cementite thickness coarsen to some extent, but both hardness and impact toughness increase to HRC 48 and 85 J, respectively. In the course of making spring, the optimum reheating austenitizing temperature for the 60Si2MnA steel is 950 ℃.
关键词:
austenitizing temperature;austenite grain;pearlite interlamellar spacing;hardness;toughness
