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The specimens of austenitic stainless steels were machined to different strain rates (105 s−1, 1050 s−1, 1500 s−1, 2100 s−1). These specimens were subjected to low-temperature sensitization (LTS) heat treatment. The LTS treatment was carried out at 475℃ and 575℃ for 24 h. Further, oxalic acid, double-loop electrochemical potentiokinetic reactivation (DL-EPR) were carried out. As-machined specimens were subjected to surface roughness measurements, optical microscopy, electron backscattered diffraction (EBSD), and Fourier transform infrared spectroscopy (FTIR) imaging measurements. Machined specimen exhibited more difficulty in passivation than the as-received specimen. The complete surface statistics were extracted. The specimens machined at a strain rate of 2100 s−1 were exhibited a higher degree of sensitization (DoS) at LTS of 575℃ and 475℃ for 24 h, respectively, than other specimens. It was found that specimens machined at a higher strain rate produced smoother roughness. FTIR imaging was used to extract the signal intensity of chromium oxide (Cr2O3) peak. Detected Cr2O3 peak/signal was strong for the specimen that exhibited lower DoS as estimated from FTIR-imaging.
N Srinivasan. Studies of Low-Temperature Sensitization after Sub-Surface Damage Evolution in Austenitic Stainless Steel. Metallography, Microstructure, and Analysis 2021, 1 -10.
AMA StyleN Srinivasan. Studies of Low-Temperature Sensitization after Sub-Surface Damage Evolution in Austenitic Stainless Steel. Metallography, Microstructure, and Analysis. 2021; ():1-10.
Chicago/Turabian StyleN Srinivasan. 2021. "Studies of Low-Temperature Sensitization after Sub-Surface Damage Evolution in Austenitic Stainless Steel." Metallography, Microstructure, and Analysis , no. : 1-10.
In this manuscript, the latest developments pertaining to sensitization are discussed. Sensitization leads to intergranular corrosion and intergranular stress corrosion cracking. The advantages and disadvantages of conventional methods to combat sensitization are elaborated. Emerging/newer techniques such as grain boundary engineering, creation of orientation gradients, and high density of twinning to improve resistance to sensitization are also covered. Detection and monitoring of deleterious phase precipitation such as carbides, nitrides, and other intermetallic phases during operation necessitate making use of nondestructive testing (NDT) methods. Possible information that we get from NDT is for material characterization includes the size, shape, and location of a defect. Herein, the significant developments for monitoring and detection of phases concerning sensitization by NDT are discussed. These range from magnetic methods to ultrasonic techniques. The multi-physics approach is essential to fully utilize NDT to ensure/predict the lifetime of the components used in the industry. Further, proper selection of suitable NDT for defect detection can avert accidents, catastrophic failures, and economic losses due to corrosion degradation. For this, the corrosion engineer/corrosionist properly apply the suitable techniques (prevention, monitoring, and assessment) to address the issues of sensitization among the wide choice available.
N. Srinivasan. Sensitization of Austenitic Stainless Steels: Current Developments, Trends, and Future Directions. Metallography, Microstructure, and Analysis 2021, 1 -15.
AMA StyleN. Srinivasan. Sensitization of Austenitic Stainless Steels: Current Developments, Trends, and Future Directions. Metallography, Microstructure, and Analysis. 2021; ():1-15.
Chicago/Turabian StyleN. Srinivasan. 2021. "Sensitization of Austenitic Stainless Steels: Current Developments, Trends, and Future Directions." Metallography, Microstructure, and Analysis , no. : 1-15.
The passive film mainly consists of oxides and hydroxide and is a key for corrosion protection of metallic materials. It increases the durability and performance of engineering components by spontaneous formation of effective, adherent barrier between the corrosive environment and a substrate. Herein, influence of plastic strain and after heat treatment on austenitic stainless steels was compared with the focus on stability of the passive film. The following materials were used in this study: Sanicro 28™, AISI 316 L, and AISI 304 L. These specimens were subjected to a true strain of 0.58. The conventional three-electrode cell was used to record the anodic potentiodynamic polarization curves. The grain size and other misorientation parameters were extracted using electron backscattered diffraction (EBSD). Fourier transform infrared spectroscopy (FTIR)-imaging was used for capturing chromium oxide (Cr2O3) peaks for all specimens. The average area of Cr2O3 peaks was compared with deformed and after heat treatment of 700 °C 30 min specimens. It was found that heat-treated specimens exhibited slightly higher average area of Cr2O3 than deformed.
N. Srinivasan; S.S. Kumaran. The Effects of Strain on Stability of Passivation in Austenitic Stainless Steels: Comparison with Heat Treatment. Experimental Techniques 2021, 45, 207 -216.
AMA StyleN. Srinivasan, S.S. Kumaran. The Effects of Strain on Stability of Passivation in Austenitic Stainless Steels: Comparison with Heat Treatment. Experimental Techniques. 2021; 45 (2):207-216.
Chicago/Turabian StyleN. Srinivasan; S.S. Kumaran. 2021. "The Effects of Strain on Stability of Passivation in Austenitic Stainless Steels: Comparison with Heat Treatment." Experimental Techniques 45, no. 2: 207-216.
The friction welding of tube to tube plate using an external tool (FWTPET) is widely deployed in several industrial applications, such as aerospace, automotive, and power plants. Moreover, for achieving a better tensile strength and hardness in the weld zone, the friction stir processing (FSP) technique was incorporated into the FWTPET process for joining aluminum alloys (AA6063 tube, AA6061 tube plate). Furthermore, it has to be noted that FWTPET was applied for joining the AA6063 tube to the AA6061 tube plate, and FSP was deployed for reinforcing the weld zone with carbon nanotube (CNT) and silicon nitride (Si3N4) particles, thereby attaining the desirable mechanical properties. Subsequently, the Taguchi L25 orthogonal array was used for identifying the most influential input and output FWTPET + FSP process parameters. Furthermore, particle swarm optimization (PSO) and the firefly algorithm (FFA) were deployed for determining the optimized input and output FWTPET + FSP process parameters. The input process parameters include CNT, Si3N4, rotational tool speed, and depth. Furthermore, the tensile strength of the welded joint was considered as the output process parameter. The process parameters predicted by PSO and FFA were compared with the experimental values. It was witnessed that deviation between the predicted and experimental values was minimal. Moreover, it was found that FFA provided a superior tensile strength prediction than PSO.
Senthil Kumaran Kumaran S; Jayakumar Kaliappan; Kathiravan Srinivasan; Yuh-Chung Hu; Sanjeevikumar Padmanaban; Srinivasan N. Realizing a Novel Friction Stir Processing-Enabled FWTPET Process for Strength Enhancement Using Firefly and PSO Methods. Materials 2020, 13, 728 .
AMA StyleSenthil Kumaran Kumaran S, Jayakumar Kaliappan, Kathiravan Srinivasan, Yuh-Chung Hu, Sanjeevikumar Padmanaban, Srinivasan N. Realizing a Novel Friction Stir Processing-Enabled FWTPET Process for Strength Enhancement Using Firefly and PSO Methods. Materials. 2020; 13 (3):728.
Chicago/Turabian StyleSenthil Kumaran Kumaran S; Jayakumar Kaliappan; Kathiravan Srinivasan; Yuh-Chung Hu; Sanjeevikumar Padmanaban; Srinivasan N. 2020. "Realizing a Novel Friction Stir Processing-Enabled FWTPET Process for Strength Enhancement Using Firefly and PSO Methods." Materials 13, no. 3: 728.
A novel phenomenon known as Industry X.0 is becoming extremely popular for digitizing and reinventing business organizations through the adaption of rapid and dynamic technological, innovational, and organizational changes for attaining the profitable revenue. This work investigates the die-casted commercially pure aluminum alloyed with 9% silicon and 3% copper (AlSi9Cu3) that is produced through the gravity die casting process. Further, the degradation of surface coating on die-casted AlSi9Cu3 alloy was explored. The acrylic paint electrodeposition (ED) coat, 2-coat polyester without primer and 3-coat polyester with epoxy primer powder coatings were used in this study. Moreover, the 3.5 wt.% of sodium chloride (3.5 wt.% of NaCl) test solution was used for electrochemical and salt spray test and the tools used to assess electrochemical properties were electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and neutral salt spray test (NSS). The microstructure of AlSi9Cu3 after corrosion exposure was investigated; also, the microstructure of coated and uncoated AlSi9Cu3 samples was analyzed by SEM microscopy after corrosion exposure. Besides, the electrochemical studies were also carried out on the Al alloy die casting. It was found that acrylic paint ED coatings exhibited higher corrosion resistance than 2-coat polyester without primer & 3-coat polyester with epoxy primer powder coatings. Acrylic paint ED coating showed higher corrosion resistance in AC and a lower value in DC and 3-coat polyester with epoxy primer powder coating displayed higher corrosion resistance in DC and a lower value in AC.
Yuh-Chung Hu; Senthil Kumaran Selvaraj; Manivannan Subramanian; Kathiravan Srinivasan; Srinivasan Narayanan. Ultrasonic Sensors-Assisted Corrosion Studies on Surface Coated AlSi9Cu3 Alloy Die Castings. Coatings 2020, 10, 85 .
AMA StyleYuh-Chung Hu, Senthil Kumaran Selvaraj, Manivannan Subramanian, Kathiravan Srinivasan, Srinivasan Narayanan. Ultrasonic Sensors-Assisted Corrosion Studies on Surface Coated AlSi9Cu3 Alloy Die Castings. Coatings. 2020; 10 (1):85.
Chicago/Turabian StyleYuh-Chung Hu; Senthil Kumaran Selvaraj; Manivannan Subramanian; Kathiravan Srinivasan; Srinivasan Narayanan. 2020. "Ultrasonic Sensors-Assisted Corrosion Studies on Surface Coated AlSi9Cu3 Alloy Die Castings." Coatings 10, no. 1: 85.
In modern times, the Industry X.0 has emerged as the paradigm that has become the core of digital technology-driven business organizations. Further, this paper establishes a tube to tube plate friction welding technology with the help of deploying an external tool, also known referred to as the FWTPET scheme. Besides, the SA213 tube and SA387 tube plate were combined by employing a unique interference fit technique. Also, the strength of this combined portion was assessed with and without the aid of a holding block. Subsequently, the analytic optimization approaches like genetic algorithm, analysis of variance, and Taguchi L9 orthogonal array design were deployed in the prediction of the optimum joining strength. Moreover, the input parameters include the projection of the tube (mm), the rotational speed of the tool (rpm), and depth of cut (mm); besides, the tensile strength is considered as the output parameter. Also, the grain size distribution around the weld zone and the presence of base metal were measured through an optical microscope as per ASTM linear intercept method. Further, it is evident that grain refinement had occurred in the weld zone, which in turn increases the tensile strength. The exceptional weld strength (tensile strength) was obtained when joining of SA213 tube and SA387 tube plate through interference fit using a holding block without a hole in the tube. Experimentally, it was found that the achieved tensile strengths were 836.8 MPa (without a hole) and 789.35 MPa (with hole) using the holding block, respectively. Additionally, it was found that in the absence of a holding block, the achieved tensile strength is 762.2 MPa (without a hole), and 700.8 MPa (with a hole), correspondingly. The deviation of tensile strength between the predicted (genetic algorithm) and experimental was found minimal. Therefore, for achieving this strength, the suitable operating parameters set include the rotational speed of the tool (1300 rpm), projection of the tube (1 mm), and depth of cut (0.5 mm) with backing block configuration.
Senthil Kumaran S; Kathiravan Srinivasan; Srinivasan Narayanan; Alex Noel Joseph Raj. Prediction of Tensile Strength in Friction Welding Joins Made of SA213 Tube to SA387 Tube Plate through Optimization Techniques. Materials 2019, 12, 4079 .
AMA StyleSenthil Kumaran S, Kathiravan Srinivasan, Srinivasan Narayanan, Alex Noel Joseph Raj. Prediction of Tensile Strength in Friction Welding Joins Made of SA213 Tube to SA387 Tube Plate through Optimization Techniques. Materials. 2019; 12 (24):4079.
Chicago/Turabian StyleSenthil Kumaran S; Kathiravan Srinivasan; Srinivasan Narayanan; Alex Noel Joseph Raj. 2019. "Prediction of Tensile Strength in Friction Welding Joins Made of SA213 Tube to SA387 Tube Plate through Optimization Techniques." Materials 12, no. 24: 4079.
Currently, the use of sensors and supporting technologies has become indispensable in the assessment of tribological behavioral patterns of composites. Furthermore, the current investigation focused on the assessment of the tribological behavior of the Al–SiCp composite for high-temperature applications. Moreover, the Al–SiCp composite was fabricated by adapting the liquid metallurgy route with varying weight percentages of SiCp (x = 3, 6, and 9). Density, hardness, and high-temperature wear tests were performed to evaluate the hardness and tribological characteristics and properties of modern-day advanced composites. Moreover, the inclusion of SiCp enhanced the advanced composite materials hardness from 60 HV to 110 HV due to a high degree of refinement of the α-phase. Subsequently, the fabricated samples’ wear behavior was assessed by varying the wear parameter viz. the applied load (20 N and 30 N) and sliding distance (250 m, 500 m, 750 m, and 1000 m) with the constant sliding velocity (0.45 m/s) for various temperatures (40 °C, 150 °C, and 250 °C). Moreover, the results revealed that the enhancement in the reinforcement percentage improves the wear resistance. Consequently, the wear rate decreased at 250 °C, possibly owing to the development of the oxide layers. Therefore, the occurrence of delamination and plastic deformation were evidenced in the wear-out surface, thereby depicting the prevalence of delamination and the abrasive wear-mechanism.
Manivannan S; Senthil Kumaran S; Srinivasan Narayanan; Kathiravan Srinivasan; Alex Noel Joseph Raj. Sensor-Assisted Assessment of the Tribological Behavioral Patterns of Al–SiCp Composites under Various Environmental Temperature Conditions. Materials 2019, 12, 4004 .
AMA StyleManivannan S, Senthil Kumaran S, Srinivasan Narayanan, Kathiravan Srinivasan, Alex Noel Joseph Raj. Sensor-Assisted Assessment of the Tribological Behavioral Patterns of Al–SiCp Composites under Various Environmental Temperature Conditions. Materials. 2019; 12 (23):4004.
Chicago/Turabian StyleManivannan S; Senthil Kumaran S; Srinivasan Narayanan; Kathiravan Srinivasan; Alex Noel Joseph Raj. 2019. "Sensor-Assisted Assessment of the Tribological Behavioral Patterns of Al–SiCp Composites under Various Environmental Temperature Conditions." Materials 12, no. 23: 4004.
The Environment Assisted Cracking (EAC) of grade P92 was investigated by employing a new testing method. The main aim is to understand the mechanism of the EAC. The specimen was subjected to a static load of approximately 90% of the material's yield strength. The experimental work was carried out under the various corrosive environments such as NaOH, KOH, HCl, CuSO4, and CH4N2S test solutions until it gets fractured, which takes a duration of one week (168 hours). These specimens were subjected to the Scanning Electron Microscope (SEM) analysis for obtaining its microstructural characterization. Further, the obtained microstructural images can be utilized to understand the failure mechanism. It can be witnessed that the majority of failures appear in the region around the coarse-grained HAZ. Subsequently, the results indicate that the passive path corrosion mechanism seems to be the preferred one as P92 welds are vulnerable to EAC.
Yuh-Chung Hu; S Manivannan; S Senthil Kumaran; Kathiravan Srinivasan; K Sathish Kumar; N Srinivasan; P Sanjeevikumar; Manivannan S; Senthil Kumaran S; Sathish Kumar K; Srinivasan Narayanan; Sanjeevikumar Padmanaban. Smart assessment of environment assisted cracking of grade 92 material using different test solutions. Materials Research Express 2019, 6, 1265h2 .
AMA StyleYuh-Chung Hu, S Manivannan, S Senthil Kumaran, Kathiravan Srinivasan, K Sathish Kumar, N Srinivasan, P Sanjeevikumar, Manivannan S, Senthil Kumaran S, Sathish Kumar K, Srinivasan Narayanan, Sanjeevikumar Padmanaban. Smart assessment of environment assisted cracking of grade 92 material using different test solutions. Materials Research Express. 2019; 6 (12):1265h2.
Chicago/Turabian StyleYuh-Chung Hu; S Manivannan; S Senthil Kumaran; Kathiravan Srinivasan; K Sathish Kumar; N Srinivasan; P Sanjeevikumar; Manivannan S; Senthil Kumaran S; Sathish Kumar K; Srinivasan Narayanan; Sanjeevikumar Padmanaban. 2019. "Smart assessment of environment assisted cracking of grade 92 material using different test solutions." Materials Research Express 6, no. 12: 1265h2.
This study dealt with characterizing oxide passive films in austenitic stainless steels with different chemical compositions. Stacking fault energy was estimated, and thermal conductivity at different temperatures (298, 673, 873 and 1073 K) were calculated. Steels specimens were plane strain compressed and subjected to anodic potentiodynamic polarization scan in a different deaerated testing environment. The deformed specimens were characterized using electron backscattered diffraction system and Fourier transform infrared spectroscopy (FTIR)-imaging. The Cr2O3 peak from FTIR-imaging was captured, and area of the peak was calculated after anodic potentiodynamic polarization scan. The intensity of Cr2O3 peak was related to deformed microstructural features.
N. Srinivasan; S. Senthil Kumaran. Role of Alloy Chemistry on Stability of Passive Films in Austenitic Stainless Steel. Journal of Materials Engineering and Performance 2019, 28, 3695 -3703.
AMA StyleN. Srinivasan, S. Senthil Kumaran. Role of Alloy Chemistry on Stability of Passive Films in Austenitic Stainless Steel. Journal of Materials Engineering and Performance. 2019; 28 (6):3695-3703.
Chicago/Turabian StyleN. Srinivasan; S. Senthil Kumaran. 2019. "Role of Alloy Chemistry on Stability of Passive Films in Austenitic Stainless Steel." Journal of Materials Engineering and Performance 28, no. 6: 3695-3703.
N Srinivasan; S Senthil Kumaran; D Venkateswarlu; Srinivasan Narayanan; Senthil Kumaran S; Venkateswarlu Devuri. Effects of in-grain misorientation developments in sensitization of 304 L austenitic stainless steels. Materials Research Express 2018, 6, 016551 .
AMA StyleN Srinivasan, S Senthil Kumaran, D Venkateswarlu, Srinivasan Narayanan, Senthil Kumaran S, Venkateswarlu Devuri. Effects of in-grain misorientation developments in sensitization of 304 L austenitic stainless steels. Materials Research Express. 2018; 6 (1):016551.
Chicago/Turabian StyleN Srinivasan; S Senthil Kumaran; D Venkateswarlu; Srinivasan Narayanan; Senthil Kumaran S; Venkateswarlu Devuri. 2018. "Effects of in-grain misorientation developments in sensitization of 304 L austenitic stainless steels." Materials Research Express 6, no. 1: 016551.
This paper focused on effect of strain on stability of passive film in three different grades of austenitic stainless steels. These were Sanicro 28TM, AISI 316L and AISI 304L steels. These specimens were subjected to unidirectional cold rolling and achieved true strain was 0.26 and 0.58. Potentiodynamic anodic polarization tests were carried out for all specimens in different test solutions. The changes in anodic polarization parameters were recorded. The deformed microstructures were characterized by using electron backscattered diffraction (EBSD). Aim of this study was to characterize chromium oxide (Cr2O3) by Fourier transform infrared spectroscopy (FTIR)-imaging. Further, an attempt was made to combine EBSD and FTIR-imaging for direct microstructural correlation.
N Srinivasan; S Senthil Kumaran; D Venkateswarlu; Srinivasan Narayanan; Senthil Kumaran S; Venkateswarlu Devuri. Effects of plastic strains on passivation behavior of different austenitic stainless steel grades. Materials Research Express 2018, 6, 026504 .
AMA StyleN Srinivasan, S Senthil Kumaran, D Venkateswarlu, Srinivasan Narayanan, Senthil Kumaran S, Venkateswarlu Devuri. Effects of plastic strains on passivation behavior of different austenitic stainless steel grades. Materials Research Express. 2018; 6 (2):026504.
Chicago/Turabian StyleN Srinivasan; S Senthil Kumaran; D Venkateswarlu; Srinivasan Narayanan; Senthil Kumaran S; Venkateswarlu Devuri. 2018. "Effects of plastic strains on passivation behavior of different austenitic stainless steel grades." Materials Research Express 6, no. 2: 026504.