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Effect of electroslag remelting and homogenization on hydrogen flaking in AMS-4340 ultra-high-strength steels

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International Journal of Minerals,Metallurgy and Materials 2019年第5期26卷 611-621页

作者： Shivraj singh Kasana O.p.pandey School of physics and Materials Science Thapar Institute of Engineering and Technology Star Wire (India) Ltd.Ballabgarh

Hydrogen flakes and elemental segregation are the main causes of steel rejection. To eliminate hydrogen flaking, the present study focuses on the manufacture of AMS-4340 ultra-high-strength steel through an alternate route. AMS-4340 was prepared using three different processing routes. The primary processing route consisted of melting in an electric arc furnace, refining in a ladle refining furnace, and vacuum degassing. After primary processing, the heat processes(D1, D2, and D3) were cast into cylindrical electrodes. For secondary processing, electroslag remelting(ESR) was carried out on the primary heats to obtain four secondary heats: E1, E2, E3, and E4. Homogenization of ingots E1, E2, E3, and E4 was carried out at 1220°C for 14, 12, 12, and 30 h, respectively, followed by an antiflaking treatment at 680°C and air cooling. In addition, the semi-finished ESR ingot E4 was again homogenized at 1220°C for 6–8 h and a second antiflaking treatment was performed at 680°C for 130 h followed by air cooling. The chemical segregation of each heat was monitored through a spectroscopy technique. The least segregation was observed for heat E4. Macrostructure examination revealed the presence of hydrogen flakes in heats E1, E2, and E3, whereas no hydrogen flakes were observed in heat E4. Ultrasonic testing revealed no internal defects in heat E4, whereas internal defects were observed in the other heats. A grain size investigation revealed a finer grain size for E4 compared with those for the other heats. Steel produced in heat E4 also exhibited superior mechanical properties. Therefore, the processing route used for heat E4 can be used to manufacture an AMS-4340 ultra-high-strength steel with superior properties compared with those of AMS-4340 prepared by the other investigated routes.

关键词： AMS-4340 steel segregation and homogenization antiflaking treatment electroslag remelting

Contrasting REE Signatures on Manganese Ores of Iron Ore Group in North Orissa, India

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Journal of Rare Earths 2007年第6期25卷 749-758页

作者： p.p.Mishra B.K.Mohapatra p.p.singh Institute of Minerals and Materials Technology Bhubaneswar 751013 India post Graduate Department of Geology Utkal University Bhubaneswar 751004 India

The distribution pattern of Rare Earth Elements （REE） in three categories of manganese ores viz. stratiform, stratabound-replacement, and detrital of precambrian Iron Ore Group from north Orissa, India was reported. These categories of Mn-ore differed in their major and trace chemistry and exhibited contrasting REE signature. The stratiform ores were relatively enriched in ∑REE content （697 μg·g^-1） and their normalized pattern showed both positive Ce and Eu anomalies, whereas the stratabound-replacement types were comparatively depleted in ∑REE content （211 μg·g^-1） and showed negative Ce and flat Eu signatures. The detrital categories showed mixed REE pattern. The data plotted in different discrimination diagrams revealed a mixed volcaniclastic and chemogenic source of material for stratiform categories, and LREE （Light Rare Earth Elements） and HREE （Heavy Rare Earth Elements） are contributed by such sources, respectively. In contrast, the stratabound ore bodies were developed during the remobilization of stratiform ores, and associated Mncontaining rocks under supergene condition followed by the redeposition of circulating mineralized colloidal solutions in structurally favorable zones. During this process, some of the constituents were found only in very low concentration within stratabound ores, and this is attributed to their poor leachability/mobility. The detrital ores did not exhibit any significant characteristic in respect of REE as their development was via a complex combination of processes involving weathering, fragmentation, recementation, and burial under soil cover.

关键词： manganese ore REE normalization geochemistry Bonai-Keonjhar belt Orissa rare earths

Thermomechanical Control process and Its Effect on Structure and properties of High Strength Low Alloy Steels

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Journal of Iron and Steel Research International 2011年第S1期18卷 511-520页

作者： singh R K p Director Kalyani Centre for Technology & innovationSurvey No.15Ahead of Renuka Mata MandirKeshavnagarPuneIndia - 411036

Low carbon steels microalloyed with small amount of carbide and/or nitride forming elements such as Nb,Ti and V with Thermomechanical controlled processing (TMCp) can give fine grained ferrite structure with high strength and superior *** present study was aimed at identifying rolling parameters as well as microstructural characterization for accomplishing high yield strength and high charpy impact property at-60℃ by controlling hot rolling parameters and microstructure Grain size distribution was also monitored and related to mechanical properties of steel.

关键词： HSLA steel thermomechanical control processing grain refining precipitation recrystalization

Bio-amelioration of alkali soils through agroforestry systems in central Indo-Gangetic plains of India

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Journal of Forestry Research 2014年第4期25卷 887-896页

作者： Y.p.singh Gurbachan singh D.K.Sharma Central Soil Salinity Research Institute Regional Research StationLucknow (U.P.) 226005 India Indian Council of Agricultural Research New Delhi 110001 India Central Soil Salinity Research Institute Karnal Haryana 132001 India

A long-term field study was initiated during 1995 at Central Soil Salinity Research Institute, Regional Research Station, Lucknow （26047＇58＂ N and 80°46＇24＂ E） to analyze the effect of agroforestry systems on amelioration of alkali soils. Three agroforestry systems （pas- toral, silvipastoral and silvicultural） were compared with the control where no agroforestry system was introduced. Tree-based silvicultural and silvipastoral systems were characterized by tree species prosopis juliflora and Acacia nilotica along with grass species Leptochloafusca, panicum maximum, Trifolium alexandrium and Chloris gayana. Growth of ten-year-old prosopis juliflora and Acacia nilotica planted in combi- nation with grasses was significantly higher over the silviculture system with the same species. Tree biomass yields of p. juliflora （77.20 t·ha-1） and A. nilotica （63.20 t·ha-1） planted under silvipastoral system were significantly higher than the sole plantation of （64.50 t·ha-1 and 52.75 t·ha-1）. Fodder yield under the pastoral system was significantly higher than the silvipastoral system during initial years but it was at par with that of silvipastoral systems after eight years of plantation. The microbial biomass carbon in the soils of silvipastoral systems was significantly higher than in soils under sole plantation of trees and control systems. The prosopis-based silvipastoral system proved more effective in reduc- ing soil pH, displacing Na＋ from the exchange complex, increasing or- ganic carbon and available N, p and K. Improvement in soil physical properties such as bulk density, porosity, soil moisture and infiltration rate was higher in the prosopis-based silvipastoral system than in the silviculture system or control On the basis of biomass production and improvement in soil health due to tree ＋ grass systems, silvipastoral agroforestry system could be adopted for sustainable reclamation ofhighly alkali soils.

关键词： agroforcstry systems alkali soils biomass production mi-crobial biomass soil amelioration

Implications of future climate change on crop and irrigation water requirements in a semi-arid river basin using CMIp6 GCMs

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Journal of Arid Land 2022年第11期14卷 1234-1257页

作者： Kunal KARAN Dharmaveer singh pushpendra K singh Birendra BHARATI Tarun p singh Ronny BERNDTSSON Department of Water Engineering and Management Central University of JharkhandBrambeRanchi 835205India Symbiosis Institute of Geo-informatics Symbiosis International(Deemed University)Pune 411016India Water Resources Systems Division National Institute of HydrologyRoorkee 247667India Division of Water Resources Engineering&Centre for Advanced Middle Eastern Studies Lund UniversityLund Box 11722100Sweden

Agriculture faces risks due to increasing stress from climate change,particularly in semi-arid *** of understanding of crop water requirement(CWR)and irrigation water requirement(IWR)in a changing climate may result in crop failure and socioeconomic problems that can become detrimental to agriculture-based economies in emerging nations *** research in CWR and IWR has largely focused on large river basins and scenarios from the Coupled Model Intercomparison project phase 3(CMIp3)and Coupled Model Intercomparison project phase 5(CMIp5)to account for the impacts of climate change on *** basins,however,are more susceptible to regional climate change,with more significant impacts on *** study estimates CWRs and IWRs for five crops(sugarcane,wheat,cotton,sorghum,and soybean)in the pravara River Basin(area of 6537 km^(2))of India using outputs from the most recent Coupled Model Intercomparison project phase 6(CMIp6)General Circulation Models(GCMs)under Shared Socio-economic pathway(SSp)245 and SSp585 *** increase in mean annual rainfall is projected under both scenarios in the 2050s and 2080s using ten selected CMIp6 *** for all crops may decline in almost all of the CMIp6 GCMs in the 2050s and 2080s(with the exceptions of ACCESS-CM-2 and ACCESS-ESM-1.5)under SSp245 and SSp585 *** availability of increasing soil moisture in the root zone due to increasing rainfall and a decrease in the projected maximum temperature may be responsible for this decline in ***,except for soybean and cotton,the projected IWRs for all other three crops under SSp245 and SSp585 scenarios show a decrease or a small increase in the 2050s and 2080s in most CMIp6 *** findings are important for agricultural researchers and water resource managers to implement long-term crop planning techniques and to reduce the negative impacts of climate change and associated rainfall variability to avert crop failure and agricultural

关键词： climate change crop water requirement irrigation water requirement CMIp6 GCMs emission scenario pravara River Basin

An Easy Access to Oxime Ethers by pd-Catalyzed C—O Cross-Coupling of Activated Aryl Bromides with Ketoximes and Chalcone Oximes

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Chinese Journal of Chemistry 2020年第8期38卷 830-836页

作者： Reeta T.M.Rangarajan Raj pal singh R.p.singh Manjula singh Centre for Fire Explosive and Environment SafetyDRDODelhiIndia Department of Chemistry University of DelhiDelhiIndia Department of Chemistry Sri Venkateswara CollegeUniversity of DelhiNew DelhiIndia Department of Chemistry Shivaji CollegeUniversity of DelhiNew DelhiIndia

An efficient pd-catalyzed method for C—O cross-coupling of ketoximes and chalcone oximes with activated aryl bromides and bromo-chalcones has been *** oxime ethers were obtained in good to excellent yields by[(π-allyl)pdCl]2/tBuXphos(L7)catalyst ***(L11)was also found to be effective for the oxime *** method offers an easy and smooth coupling of chalcone oximes with activated aryl bromides and bromo-chalcones,which has not been previously explored.

关键词： coupling coupling bromide

Stability investigation of road cut slope in basaltic rockmass,Mahabaleshwar,India

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Geoscience Frontiers 2015年第6期6卷 837-845页

作者： Ashutosh Kainthola p.K.singh T.N.singh Department of Earth Sciences Indian Institute of Technology Bombay

Slope failures along hill cut road slopes are the major nuisance for commuters and highway planners as they put the human lives at huge risk,coupled with immense monetary *** of these vulnerable cut slopes entails the assessment and estimation of the suitable material strength input parameters to be used in the numerical models to accomplish a holistic stability *** the present study a 60 m high,basaltic and lateritic road cut hill slope in Mahabaleshwar,India,has been considered.A number of samples of both basalt and laterite,in their natural state were tested in the laboratory and the evaluated maximum,minimum and mean strength parameters were employed for the three cases in a distinct element numerical *** Mohr-Coulomb failure criterion has been incorporated in the numerical model for the material as well as the *** numerical investigation offered the factor of safety and insights into the probable deformational mechanism for the three ***,several critical parameters have also been judged from the study viz.,mode of failure,factor of safety,shear strain rate,displacement magnitudes *** result of this analysis shows that the studied section is prone to recurrent failures due to the capping of a substantially thick layer of weaker lateritic material above the high strength basaltic rock *** triggering mechanisms like heavy precipitation and earthquake may also accelerate the slope failure in this *** study also suggests employing instant preventive measures to avert the further risk of damage.

关键词： Slope stability UDEC Basalt Mahabaleshwar Road cut

Ichnofossils from the Miocene Middle Bhuban Formation, Mizoram, Northeast India and their paleoenvironmental Significance

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Acta Geologica Sinica(English Edition) 2013年第5期87卷 1460-1471页

作者： Kapesa LOKHO Birendra p.singh Wadia Institute of Himalayan Geology (WIHG) Center of Advanced Study in Geology Panjab University

An ichnofossil assemblage is preserved in sediments of the Middle Bhuban Formation, Surma Group, of Miocene age from the Durtlang and Chanmari sections, Aizawl district, Mizoram, northeastern India. The studied sections comprise a thick, bioturbated and thinly bedded sandstone-silty shale facies. The preserved ichnofossils show high density and low diversity with the assemblage represented by feeding and resting traces, i.e., psilonichnus upsilon Frey et al., 1984, Ophiomorpha isp., Teichichnus spiralis Mikulas. 1990, Skolithos isp., palaeophycus isp., and other horizontal burrows. Sedimentary structures associated with these traces are mainly cross bedding, flaser bedding and slump structures. Considering the distribution of the psilonichnus ichnogenus across an integrated ichnological-sedimentological framework, the stratigraphic interval of the Middle Bhuban Formation, in which they occur, are interpreted to have been deposited under a shallow, marginal-marine channel complex dominated by tidal channels developed in quiet, brackish-water portions of a delta plain.

关键词： Ichnology Miocene (Burdigalian) psilonichnus Skolithos Assam-Arakan Basin

Implications of multipurpose tree leaf application on wheat productivity in dry tropics

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Journal of Forestry Research 2013年第4期24卷 777-782页

作者： Rajani Srivastava K.p.singh Department of Botany Banaras Hindu University

Leaves of multipurpose tree species （those providing more than one function or product of human use） can serve as sources of fer- tilizer for nutrient supply, especially nitrogen （N）. In this study chopped leaves of tropical tree species （5 N-fixing species, 5 non-N-fixing species and combinations of 5 N-fixing with a non-N-fixing species） were in- corporated in soil to evaluate its effects on wheat biological productivity （including grain yield, GyIELD） under dryland conditions. High quality leaves of N-fixing tree species （e.g. Dalbergia sissoo, Cassia fistula and prosopis cineraria） had lower carbon/nitrogen （C/N）, lignin/nitrogen （L^o/N）, polyphenol/nitrogen （ppt/N） and lignin＋polyphenol /nitrogen （L~＋ppL/N） ratios than low quality leaves of non-N-fixing species. Com- bination treatments had intermediate values of different parameters, Application of high quality leaves caused greater increases in wheat productivity and yield than other species.

关键词： multipurpose tree leaves chemical quality index grain yield,N-fixing species non-N fixing species Dryland agriculture