Browsing by Author "CHOU, CP"

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A NEW ORIENTATION RELATIONSHIP BETWEEN M6C CARBIDE AND THE AUSTENITE MATRIX IN AN FE-MN-AL-MO-C ALLOY
(1993-07-01)
PENG, SW
;
TSAI, TY
;
CHOU, CP
;
交大名義發表
;
機械工程學系
A NEW TECHNIQUE FOR REDUCING THE RESIDUAL-STRESS INDUCED BY WELDING IN TYPE-304 STAINLESS-STEEL
(1995-01-15)
LIN, YC
;
CHOU, CP
;
機械工程學系
;
Department of Mechanical Engineering
A new Technique named as ''parallel heat welding'' (PHW) is developed for the reduction of residual stress. It is performed by a pair of parallel heating torches attached to the welding torch on both sides as a movable heat source during welding. Autogenous gas tungsten are welding process was used in type 304 stainless steel. The experimental results showed that the maximum principal residual stress and parallel welding direction stress can be reduced by 21-32 % when the conventional welding(CW) process is replaced by the parallel heat welding process. The elevation of equilibrium temperature during welding process is a main mechanism for the reduction of residual stress in PHW process.
DO3-B2-ALPHA-PHASE TRANSITION IN AN FE-MN-AL-C WELDMENT
(1993-05-15)
LIN, YL
;
CHOU, CP
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
EFFECT OF ALUMINUM ON TRIP FE-MN-AL ALLOY-STEELS AT ROOM-TEMPERATURE
(1993-02-28)
CHEN, FC
;
CHOU, CP
;
LI, P
;
CHU, SL
;
機械工程學系
Fe-Mn-Al alloy steel has undergone many significant developments during the past few years, and it is considered to be a steel of high strength and toughness. Studies and test results have shown that Fe-Mn-Al is a good potential replacement for conventional stainless steels which contain expensive nickel and chromium additions. Recently, it has been found that strain-induced martensitic transformation at room temperature is possible in austenitic Fe-Mn-Al alloy. Further study has shown that the alpha' martensite can improve the mechanical properties of these Fe-Mn-Al alloys. However, as the aluminium content increases, the strain-induced phase transformation is inhibited. Moreover, the mechanical properties of these materials are very dependent on the aluminium content.
EFFECT OF CARBON ON THE WELDABILITY OF FE-MN-AL ALLOYS
(1990-02-01)
CHOU, CP
;
LEE, CH
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
ERROR INDUCED BY LOCAL YIELDING AROUND HOLE IN HOLE DRILLING METHOD FOR MEASURING RESIDUAL-STRESS OF MATERIALS
(1995-06-01)
LIN, YC
;
CHOU, CP
;
機械工程學系
;
Department of Mechanical Engineering
The hole drilling strain gauge method described in ASTM standard E837 is a popular method for measuring residual stresses near the surface of a material. However, some measuring errors have been found that may affect the accuracy of the measurement The present paper aims to improve the accuracy by analysing the errors caused by local yielding around the hole. The materials used were 304 stainless steel, 5052 H32 aluminium alloy, and 1018 low carbon steel. The experimental results showed that the error induced by local yielding around the hole is negligible when the residual stresses measured are less than 65% of the yield stress. The maximum errors are in the range 32-47% and occur when the calibrated tensile stress is 95% of the yield stress of the test material. The maximum plastic error occurs in the perfect elastic-plastic material. The plastic error increases as the value of the Young's modulus of the material used increases.
EVIDENCE OF STRAIN-INDUCED MARTENSITIC-TRANSFORMATION IN FE-MN-AL AUSTENITIC ALLOY-STEELS AT ROOM-TEMPERATURE
(1991-03-01)
CHEN, FC
;
LI, P
;
CHU, SL
;
CHOU, CP
;
機械工程學系
GROWTH AND CHARACTERIZATION OF CARBON NITRIDE THIN-FILMS PREPARED BY ARC-PLASMA JET CHEMICAL-VAPOR-DEPOSITION
(1995-11-06)
YEN, TY
;
CHOU, CP
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
Carbon nitride thin films have been successfully grown on nickel substrates by a novel are-plasma jet chemical vapor deposition. These films were characterized by Auger electron spectroscopy, transmission electron microscopy, and Raman spectroscopy. Small grains (similar to 0.1 mu m) as well as nanocrystallites found in the films were identified to be beta-C3N4. Raman spectroscopy also confirmed the existence of beta-C3N4 phase in the films through five pronounced Raman bands as expected from the Hooke's law approximation based on the vibrational frequencies obtained in analogous compound, beta-Si3N4. (C) 1995 American Institute of Physics.
M23C6 CARBIDE IN AN FE-26.6MN-8.8AL-0.61C ALLOY
(1992-07-01)
LIN, YL
;
CHOU, CP
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
M2C STRUCTURE IN AN FE-24.6MN-6.6AL-3.1MO-1.0C-ALLOY
(1992-06-15)
PENG, SW
;
CHOU, CP
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
MICROSTRUCTURAL STUDIES OF FE-MN-AL-SI WELD METAL
(1989-06-01)
CHOU, CP
;
LEE, CH
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
ORIENTATION RELATIONSHIPS BETWEEN M2C CARBIDE AND THE AUSTENITE MATRIX IN AN FE-MN-AL-MO-C ALLOY
(1993-05-01)
PENG, SW
;
CHOU, CP
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
M2C carbides were observed to precipitate within the austenite matrix of an Fe-24-6Mn-6.6Al-3.1Mo-1.0C alloy after quenching from 1200-degrees-C and aging at 750-degrees-C. By means of transmission electron microscopy (TEM) and diffraction techniques, the orientation relationships between M2C (p) and the austenite (gamma) matrix were determined to be: (0001)p//(111)gamma, (1120BAR)p//(110BAR)gamma, (1100BAR)p//(112BAR)gamma. M2C carbide has been reported by many researchers to precipitate from the ferrite matrix or along austenite/ferrite boundaries in alloy steels containing Mo. However, little information concerning the formation of M2C in the austenite matrix has been provided. This investigation presents the first evidence for the existence of M2C carbide wholly within the austenite matrix and its relationship to the austenite. The energy-dispersive spectrometry (EDS) analyses were performed on M2C carbides, and the results indicate that the solubility of the M2C carbide for foreign atoms other than Mo is very limited.
ORIENTATION RELATIONSHIPS BETWEEN M6C CARBIDE AND ITS MATRICES IN AN FE-24.6MN-6.6A1-3.1MO-1.0C-ALLOY
(1992-01-15)
PENG, SW
;
CHOU, CP
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
PHASE DECOMPOSITIONS OF FE-MN-AL-NI ORDERED ALLOY
(1991-07-01)
LIN, YL
;
CHOU, CP
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
PHASE-SEPARATION IN AN FE-23.0MN-10.6AL-6.4 NI ORDERED ALLOY
(1991-11-01)
LIN, YL
;
CHOU, CP
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
PHASE-SEPARATION IN AN FE-23.0MN-10.6AL-6.4 NI ORDERED ALLOY
(1991-11-01)
LIN, YL
;
CHOU, CP
;
機械工程學系
;
Department of Mechanical Engineering
REDUCTION OF RESIDUAL-STRESS BY PARALLEL HEAT WELDING IN SMALL SPECIMENS OF TYPE-304 STAINLESS-STEEL
(1992-02-01)
CHOU, CP
;
LIN, YC
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
A new method designated 'parallel heat welding' has been developed for the reduction of residual stress in small specimens. It is carried out using a pair of parallel heating torches attached one either side to a welding torch as a movable heat source during welding. Six different welding conditions were applied to an autogenous gas tungsten arc welded Type 304 stainless steel. During welding, the thermal cycles of four locations in the weldment were recorded to investigate the action of thermal stress and to evaluate the effect of the parallel heat sources on sensitisation. In addition, an optical microscope was used to observe the degree of sensitisation. The experimental results show that the maximum principal residual stress and parallel welding direction stress can be reduced by 21-32% when the conventional welding process is replaced by parallel heat welding. The equilibrium temperature of the welded plate can be increased from 45 to 240-degrees-C. Also, based on the exposure time recorded at temperatures in the range 600-850-degrees-C, and metallographical observations, it was found that parallel heat welding has no influence on the degree of sensitisation of austenitic stainless steel weldments.
RESIDUAL-STRESS DUE TO PARALLEL HEAT WELDING IN SMALL SPECIMENS OF TYPE 304 STAINLESS-STEEL
(1992-09-01)
LIN, YC
;
CHOU, CP
;
機械工程學系
;
Department of Mechanical Engineering
The aim of this study was to verify the mechanism of parallel heat welding (PHW) and to investigate the thermal and residual stresses due to welding. In this study, autogenous gas tungsten arc welding was used on type 304 stainless steel. Wells' one-dimensional stress distribution model was assumed to explain the behaviour of stress introduced by conventional welding (CW) and PHW processes. A step by step method proposed by Tall was applied to calculate theoretical thermal and residual stresses. Comparison between experimental and analytical results showed that the predicted results calculated using a modified Wells' model are in agreement with the experimental results, and that the elevation of equilibrium temperature during the welding process is an important mechanism for the reduction of residual stress in the PHW process. The theoretical curves of residual stress calculated for thermal cycles corresponding to CW and PHW processes show fairly good agreement with experimental results in the vicinity of the fusion zone.
SYNTHESIS OF CARBON NITRIDE FILMS BY MAGNETICALLY ROTATED ARC-PLASMA JET CHEMICAL-VAPOR-DEPOSITION
(1995-08-01)
YEN, TY
;
CHOU, CP
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
Carbon Nitride films have been grown on nickel substrates by magnetically rotated arc-plasma jet chemical vapor deposition (CVD). These films were characterized by scanning electron microscopy (SEM), wavelength dispersive X-ray spectrometry (WDS) transmission electron microscopy (TEM), and Raman spectroscopy. Small grains (similar to 0.1 mu m) as well as nanocrystallites found in the films were identified to be beta-C3N4. Raman spectrum also confirmed the existence of beta-C3N4 phase in the films through three pronounced Raman bands at low frequency as expected from the Hooke's law approximation.
TEM STUDIES OF DO3 STRUCTURE IN FE-30MN-9AL-0.4C WELD METAL
(1989-11-01)
CHOU, CP
;
LEE, CH
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University