Joydeep Pal - Academia.edu (original) (raw)

Papers by Joydeep Pal

Research paper thumbnail of Creep deformation of Alloys 617 and 276 at 750–950 °C

Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2009

Alloys 617 and 276 were subjected to time-dependent deformation at elevated temperatures under su... more Alloys 617 and 276 were subjected to time-dependent deformation at elevated temperatures under sustained loading of different magnitudes. The results indicate that Alloy 617 did not exhibit strains exceeding 1 percent (%) in 1000h at 750, 850 and 950°C when loaded to 10% of its yield strength (YS) values at these temperatures. However, this alloy was not capable of sustaining

Research paper thumbnail of Corrigendum to “Dynamic strain ageing of an austenitic superalloy—Temperature and strain rate effects

Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2008

Research paper thumbnail of Time-Dependent Fatigue Crack Propagation Behavior of Two Solid-Solution-Strengthened Ni-Based Superalloys---INCONEL 617 and HAYNES 230

Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2011

The fatigue crack propagation (FCP) as well as the sustained loading crack growth (SLCG) behavior... more The fatigue crack propagation (FCP) as well as the sustained loading crack growth (SLCG) behavior of two solid-solution-strengthened Ni-based superalloys, INCONEL 617 (Special Metals Corporation Family of Companies) and HAYNES 230 (Haynes International, Inc., Kokomo, IN), were studied at increased temperatures in laboratory air under a constant stressintensity-factor (K) condition. The crack propagation tests were conducted using a baseline cyclic triangular waveform with a frequency of 1 3 Hz. Various hold times were imposed at the maximum load of a fatigue cycle to study the hold time effect. The results show that a linear elastic fracture mechanics (LEFM) parameter, stress intensity factor (K), is sufficient to describe the FCP and SLCG behavior at the testing temperatures ranging from 873 K to 1073 K (600°C to 800°C). As observed in the precipitation-strengthened superalloys, both INCONEL 617 and HAYNES 230 exhibited the time-dependent FCP, steady SLCG behavior, and existence of a damage zone ahead of crack tip. A thermodynamic equation was adapted to correlate the SLCG rates to determine thermal activation energy. The fracture modes associated with crack propagation behavior were discussed, and the mechanism of time-dependent FCP as well as SLCG was identified. Compared with INCONEL 617, the lower crack propagation rates of HAYNES 230 under the time-dependent condition were ascribed to the different fracture mode and the presence of numerous W-rich M 6 C-type and Cr-rich M 23 C 6 -type carbides. Toward the end, a phenomenological model was employed to correlate the FCP rates at cycle/time-dependent FCP domain. All the results suggest that an environmental factor, the stress assisted grain boundary oxygen embrittlement (SAGBOE) mechanism, is mainly responsible for the accelerated timedependent FCP rates of INCONEL 617 and HAYNES 230.

Research paper thumbnail of Temperature and Load Ratio Effects on Crack-Growth Behavior of Austenitic Superalloys

Journal of Engineering Materials and Technology-transactions of The Asme, 2010

Research paper thumbnail of Tensile deformation of a nickel-base superalloy for application in hydrogen generation

International Journal of Hydrogen Energy, 2008

Austenitic Alloy C-22 has been proposed to be a structural material in sulfuric acid decompositio... more Austenitic Alloy C-22 has been proposed to be a structural material in sulfuric acid decomposition process related to a thermochemical cycle associated with hydrogen generation using nuclear heat. In view of unusually high operating temperatures associated with this cycle, tensile properties of this alloy have been determined as functions of temperature and strain rate. A mechanistic understanding of tensile deformation based on activation energy, work-hardening index and dislocation density has been presented. Furthermore, the results of fractographic evaluations of the tested specimens have been included.

Research paper thumbnail of Dynamic strain ageing of an austenitic superalloy—Temperature and strain rate effects

Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2008

The tensile data involving austenitic Alloy C-276 suggest that this alloy is capable of maintaini... more The tensile data involving austenitic Alloy C-276 suggest that this alloy is capable of maintaining appreciable structural strength at temperatures relevant to the sulfuric acid decomposition process related to the nuclear hydrogen initiative. Reduced failure strain and formation of serrations, characteristics of dynamic strain ageing (DSA), were noted within susceptible temperature regimes. An average activation energy of 55 kJ/mol, and work hardening index ranging from 0.68 to 0.75 were determined as functions of different testing temperature and strain rates. The occurrence of DSA was also associated with enhanced dislocation density. Depending on the testing temperature, a combination of ductile and intergranular brittle failures was observed with the tested specimens.

Research paper thumbnail of Creep deformation of Alloys 617 and 276 at 750–950 °C

Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2009

Alloys 617 and 276 were subjected to time-dependent deformation at elevated temperatures under su... more Alloys 617 and 276 were subjected to time-dependent deformation at elevated temperatures under sustained loading of different magnitudes. The results indicate that Alloy 617 did not exhibit strains exceeding 1 percent (%) in 1000h at 750, 850 and 950°C when loaded to 10% of its yield strength (YS) values at these temperatures. However, this alloy was not capable of sustaining

Research paper thumbnail of Corrigendum to “Dynamic strain ageing of an austenitic superalloy—Temperature and strain rate effects

Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2008

Research paper thumbnail of Time-Dependent Fatigue Crack Propagation Behavior of Two Solid-Solution-Strengthened Ni-Based Superalloys---INCONEL 617 and HAYNES 230

Metallurgical and Materials Transactions A-physical Metallurgy and Materials Science, 2011

The fatigue crack propagation (FCP) as well as the sustained loading crack growth (SLCG) behavior... more The fatigue crack propagation (FCP) as well as the sustained loading crack growth (SLCG) behavior of two solid-solution-strengthened Ni-based superalloys, INCONEL 617 (Special Metals Corporation Family of Companies) and HAYNES 230 (Haynes International, Inc., Kokomo, IN), were studied at increased temperatures in laboratory air under a constant stressintensity-factor (K) condition. The crack propagation tests were conducted using a baseline cyclic triangular waveform with a frequency of 1 3 Hz. Various hold times were imposed at the maximum load of a fatigue cycle to study the hold time effect. The results show that a linear elastic fracture mechanics (LEFM) parameter, stress intensity factor (K), is sufficient to describe the FCP and SLCG behavior at the testing temperatures ranging from 873 K to 1073 K (600°C to 800°C). As observed in the precipitation-strengthened superalloys, both INCONEL 617 and HAYNES 230 exhibited the time-dependent FCP, steady SLCG behavior, and existence of a damage zone ahead of crack tip. A thermodynamic equation was adapted to correlate the SLCG rates to determine thermal activation energy. The fracture modes associated with crack propagation behavior were discussed, and the mechanism of time-dependent FCP as well as SLCG was identified. Compared with INCONEL 617, the lower crack propagation rates of HAYNES 230 under the time-dependent condition were ascribed to the different fracture mode and the presence of numerous W-rich M 6 C-type and Cr-rich M 23 C 6 -type carbides. Toward the end, a phenomenological model was employed to correlate the FCP rates at cycle/time-dependent FCP domain. All the results suggest that an environmental factor, the stress assisted grain boundary oxygen embrittlement (SAGBOE) mechanism, is mainly responsible for the accelerated timedependent FCP rates of INCONEL 617 and HAYNES 230.

Research paper thumbnail of Temperature and Load Ratio Effects on Crack-Growth Behavior of Austenitic Superalloys

Journal of Engineering Materials and Technology-transactions of The Asme, 2010

Research paper thumbnail of Tensile deformation of a nickel-base superalloy for application in hydrogen generation

International Journal of Hydrogen Energy, 2008

Austenitic Alloy C-22 has been proposed to be a structural material in sulfuric acid decompositio... more Austenitic Alloy C-22 has been proposed to be a structural material in sulfuric acid decomposition process related to a thermochemical cycle associated with hydrogen generation using nuclear heat. In view of unusually high operating temperatures associated with this cycle, tensile properties of this alloy have been determined as functions of temperature and strain rate. A mechanistic understanding of tensile deformation based on activation energy, work-hardening index and dislocation density has been presented. Furthermore, the results of fractographic evaluations of the tested specimens have been included.

Research paper thumbnail of Dynamic strain ageing of an austenitic superalloy—Temperature and strain rate effects

Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2008

The tensile data involving austenitic Alloy C-276 suggest that this alloy is capable of maintaini... more The tensile data involving austenitic Alloy C-276 suggest that this alloy is capable of maintaining appreciable structural strength at temperatures relevant to the sulfuric acid decomposition process related to the nuclear hydrogen initiative. Reduced failure strain and formation of serrations, characteristics of dynamic strain ageing (DSA), were noted within susceptible temperature regimes. An average activation energy of 55 kJ/mol, and work hardening index ranging from 0.68 to 0.75 were determined as functions of different testing temperature and strain rates. The occurrence of DSA was also associated with enhanced dislocation density. Depending on the testing temperature, a combination of ductile and intergranular brittle failures was observed with the tested specimens.