Rajneesh Kumar Gupta
@nmlindia.org
Principal Scientist
national metallurgical laboratory
RESEARCH INTERESTS
Welding, mechanical properties, fracture toughness, structural integrity, joining, modeling
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Mayur P. Singh, Kanwer Singh Arora, Ankit Gupta, Rajneesh Kumar, Dinesh Kumar Shukla, and Pranav Jhunjhunwala
Springer Science and Business Media LLC
Mayur Pratap Singh, Pavan Kumar Meena, Kanwer Singh Arora, Rajneesh Kumar, and Dinesh Kumar Shukla
Emerald
Purpose This paper aims to measure peak temperatures and cooling rates for distinct locations of thermocouples in the butt weld joint of mild steel plates. For experimental measurement of peak temperatures, K-type thermocouples coupled with a data acquisition system were used at predetermined locations. Thereafter, Rosenthal’s analytical models for thin two-dimensional (2D) and thick three-dimensional (3D) plates were adopted to predict peak temperatures for different thermocouple positions. A finite element model (FEM) based on an advanced prescribed temperature approach was adopted to predict time-temperature history for predetermined locations of thermocouples. Design/methodology/approach Comparing experimental and Rosenthal analytical models (2D and 3D) findings show that predicted and measured peak temperatures are in close agreement, while cooling rates predicted by analytical models (2D, 3D) show significant variation from measured values. On the other hand, 3D FEM simulation predicted peak temperatures and cooling rates for different thermocouple positions are close to experimental findings. Findings The inclusion of filler metal during simulation of welding rightly replicates the real welding situation and improves outcomes of the analysis. Originality/value The present study is an original contribution to the field of welding technology.
Rajan Choudhary, Rajneesh Kumar, Ankush Kumar, Santanu Pathak, and Abhinay Kumar
Springer Nature Singapore
Raj Kumar, Mohammad Mursaleen, G. A. Harmain, and Ashutosh Kumar
Springer Nature Singapore
Raj Kumar, R. G. Deshpande, B. Gopinath, Jayasheel Harti, Madeva Nagaral, and V. Auradi
Springer Science and Business Media LLC
Yash Khandelwal, Rajneesh Kumar Gupta, K. K. Verma, and Amitava Mandal
Springer Singapore
Mayur Pratap Singh, Kanwer Singh Arora, Rajneesh Kumar, Dinesh Kumar Shukla, and S. Siva Prasad
Wiley
Akhil Khajuria, Modassir Akhtar, Raman Bedi, Rajneesh Kumar, Mainak Ghosh, C.R. Das, and Shaju K. Albert
Elsevier BV
Akhil Khajuria, Modassir Akhtar, Raman Bedi, Rajneesh Kumar, Mainak Ghosh, C. R. Das, and Shaju K. Albert
Informa UK Limited
Conventional P91 and boron modified P91-steels were considered in the present investigation. Using Gleeble, weld intercritical heat-affected zone (ICHAZ) was processed. Conventional microscopy was done along with electron back-scattered diffraction for both specimens. Lath boundary of martensite was more, and preferably oriented for P91B-ICHAZ than P91-ICHAZ. Lattice strain was high and lath mobility was low for P91B-ICHAZ in comparison to P91-ICHAZ. Large fraction of ferritic grain structure (39.1%) and small fraction of fresh martensitic grain structure (9.5%) in P91-ICHAZ, whereas small fraction of ferritic grain structure (10.7%) and large fraction of fresh martensitic grain structure (32.7%) in P91B-ICHAZ was observed. However, tempered martensite exhibited meager variation. These differences between ICHAZ simulations were attributed to the presence of 100ppm-boron in P91B-steel.
Mayur Pratap Singh, Dinesh Kumar Shukla, Rajneesh Kumar, and Kanwer Singh Arora
Emerald
PurposeThe key purpose of conducting this review is to identify the issues that affect the structural integrity of pipeline structures. Heat affected zone (HAZ) has been identified as the weak zone in pipeline welds which is prone to have immature failuresDesign/methodology/approachIn the present work, literature review is conducted on key issues related to the structural integrity of pipeline steel welds. Mechanical and microstructural transformations that take place during welding have been systematically reviewed in the present review paper.FindingsKey findings of the present review underline the role of brittle microstructure phases, and hard secondary particles present in the matrix are responsible for intergranular and intragranular cracks.Research limitations/implicationsThe research limitations of the present review are new material characterization techniques that are not available in developing countries.Practical implicationsThe practical limitations are new test methodologies and associated cost.Social implicationsThe fracture of pipelines significantly affects the surrounding ecology. The continuous spillage of oil pollutes the land and water of the surroundings.Originality/valueThe present review contains recent and past studies conducted on welded pipeline steel structures. The systematic analysis of studies conducted so far highlights various bottlenecks of the welding methods.
Anuranjan Kumar, Kanwer Singh Arora, Rajneesh Kumar Gupta, and G. A. Harmain
Springer Science and Business Media LLC
Mayur Pratap Singh, Kanwer Singh Arora, Nikhil Shajan, Sangeetha Ranga Pandu, Mahadev Shome, Rajneesh Kumar, and Dinesh Shukla
Springer Science and Business Media LLC
Akhil Khajuria, Rajneesh Kumar, and Raman Bedi
Springer Science and Business Media LLC
Manoj Kumar, Saurav Datta, and Rajneesh Kumar
Springer Science and Business Media LLC
MayurPratap Singh, Rajneesh Kumar, Dinesh Kumar Shukla, and Kanwer Singh Arora
IOP Publishing
In the present work, phase transformation behavior and structure-property correlation in X-80 steel was analyzed at three distinct austenitizing peak temperatures (1250 °C, 1030 °C and 950 °C). Dilation studies and simulations of Charpy size samples were carried out using Gleeble 3800 thermal simulator. Dilation studies indicated that the dissolution of Nb rich carbides occurred at 1020 °C. During cooling from 1250 °C, mixed microstructure of bainitic ferrite and martensite formed at fast (200 °C s−1 −80 °C s−1) and medium (50 °C s−1–40 °C s−1) cooling rates. For slow cooling rates (20 °C s−1–0.5 °C s−1), ferrite/pearlite microstructure was obtained. For lower peak temperatures 1030 °C and 950 °C, mixed microstructure of bainitic ferrite and martensite was observed for fast cooling rates. Whereas, ferrite/pearlite with small fraction of bainitic ferrite nucleated in the microstructure at medium and slow cooling rates. Highest area fraction of M-A (8%) was observed at medium cooling rates (50 °C s−1–40 °C s−1) for 1250 °C peak temperature. Charpy size samples simulated for a 1250 °C peak temperature, exhibited the minimum notch toughness at 12.5 °C s−1, due to deleterious effect of granular bainite and M-A constituents. Simulated samples at lower peak temperatures 1030 °C and 950 °C exhibited higher notch toughness due to a mixed microstructure of bainitic ferrite and ferrite-pearlite.
Akhil Khajuria, Raman Bedi, and Rajneesh Kumar
Springer Singapore
Santosh Kumar Sahu, Nimai Haldar, Saurav Datta, and Rajneesh Kumar
Elsevier BV
Modassir Akhtar, Akhil Khajuria, Jitendra K. Sahu, J. Swaminathan, Rajneesh Kumar, Raman Bedi, and Shaju K. Albert
Springer Science and Business Media LLC
Nimai Haldar, Saurav Datta, and Rajneesh Kumar
Springer Science and Business Media LLC
Saurabh Kumar Gupta, KN Pandey, and Rajneesh Kumar
SAGE Publications
Joining of dissimilar aluminum alloys are widely used in automobile, aerospace and shipbuilding industries. The defect-free joining of aluminum alloys using conventional technique is a challenging task for a welding engineer. Friction stir welding has been established as one of the most promising processes for defects-free joining of aluminum alloys. In this study, a hybrid approach of grey relational analysis with principal component analysis, is applied for multi-objective optimization of process parameters for friction stir welding of dissimilar AA5083/AA6063 aluminum alloys. Three responses namely tensile strength, average hardness at weld nugget zone and average grain size at weld nugget zone, and four process parameters with three levels have been selected for the study. Taguchi method based L27 orthogonal array design matrix is used for experiments. The optimal set of process parameters using hybrid approach was found as 900 r/min of tool rotational speed, 60 mm/min of welding speed, 18 mm of shoulder diameter and 5 mm of pin diameter. Improved performance of each response was obtained from the confirmation tests at optimum level of parameters.
Saurabh Kumar Gupta, KN Pandey, and Rajneesh Kumar
SAGE Publications
The present research investigates the application of artificial intelligence tool for modelling and multi-objective optimization of friction stir welding parameters of dissimilar AA5083-O–AA6063-T6 aluminium alloys. The experiments have been conducted according to a well-designed L27 orthogonal array. The experimental results obtained from L27 experiments were used for developing artificial neural network-based mathematical models for tensile strength, microhardness and grain size. A hybrid approach consisting of artificial neural network and genetic algorithm has been used for multi-objective optimization. The developed artificial neural network-based models for tensile strength, microhardness and grain size have been found adequate and reliable with average percentage prediction errors of 0.053714, 0.182092 and 0.006283%, respectively. The confirmation results at optimum parameters showed considerable improvement in the performance of each response.
Saurabh Kumar Gupta, K.N. Pandey, and Rajneesh Kumar
Inderscience Publishers
Gopinath K, R.K. Gupta, J.K. Sahu, P.K. Ray, and R.N. Ghosh
Elsevier BV
Rajneesh KUMAR, Kanwer SINGH, and Sunil PANDEY
Elsevier BV