Detailed characterization of Fe-3.2%Si steel after different stages of processing trails including hot-rolling, normalization annealing, cold-rolling with intermediate annealing, and finally, decarburization/primary annealing and secondary annealing has been carried out. The evolution of ferrite grain structure, grain boundary characteristics, and the micro-texture of the samples are characterized using electron backscatter diffraction (EBSD). The inhibiting precipitates such as MnS and CuS are studied under scanning and transmission electron microscopy (SEM and TEM). The evolution of ferrite grain structure and texture are explained considering the mechanisms (role of inhibitors, crystal orientation, special boundary, high energy medium angle boundary, grain boundary curvature) responsible for the abnormal growth of Goss oriented grains after final annealing treatment. Extremely coarse Goss oriented grains (as large as >20 mm) have been developed in this study. An analytical approach is presented at the end to explain the texture evolution during processing considering the Taylor factor maps (for different loading conditions) and the prediction of limiting ferrite grain size for abnormal grain growth, considering the size and fraction of the precipitates along with their coarsening and dissolution kinetics.

The engineering systems for iron and steel production in an integrated steel company are composed of multitudes of complex machineries and components for handling and transfer of large volume of aggres-sive raw material and intermediate products. This leads to abrasion, wear and other service induced degradation of components and machineries resulting in huge losses owing to decreased component ser-vice life, production losses, energy losses and increased maintenance cost. This inevitably requires sys-tematic approach towards a productive maintenance strategy in order to prevent frequent failures of machineries and components adding to the operating costs and consuming more resources. Wear pre-vention and control through judicious selection and use of superior materials for machineries compo-nents have received greater attentions in recent times as a solution to the maintenance problems. The present paper highlights various types of wear encountered in steel processing industries, the metallur-gical factors influencing wear and the strategy/ techniques to prevent it. This also includes field examples of such an attempt towards selection guidelines and their uses for wear prone components. The success-ful applications of some of the wear resistant materials, such as, high-Cr iron alloys, tool and alloy steels, etc.; for some of the wear prone components, such as, protective liners for material handling systems for coke and sinter, knives for shearing and chopping applications for steel strips and sheets, steel mill rolls, etc; have been enumerated.Copyright (c) 2022 Elsevier Ltd. All rights reserved.Selection and peer-review under responsibility of the scientific committee of the Symposium on Failure and Preventive Maintenance of Machineries 2022.

Strengthening by micro-alloying permits a remarkable reduction in carbon content which greatly improves weldability and notch toughness. As the strength requirement has increased, a shift from traditional ferrite/pearlite (FP) microstructure produced by a conventional alloy design to a ferrite/acicular ferrite (F/AF) microstructure has been necessary. The ultimate steel microstructures and final properties of steel are shown to be highly dependent on both controlled rolling and accelerated cooling conditions. Two steel grades one having richer chemistry alloyed with Nb–V–Mo–Ti and other lean chemistry with Nb–Ti addition thermo-mechanically processed in such a way that Mo containing steel yielded polygonal ferrite–bainite structure. Whereas, high reduction per pass and high cooling rate in Nb–Ti steel resulted into fine acicular ferrite and bainite microstructure. This steel possessed attractive properties in terms of YS: 584–592 MPa, UTS: 763–803 MPa, %EL: 29–31, YS/UTS: 0.72–0.77 and Charpy impact energy of 210–222 J compared to that of Nb–V–Mo–Ti bearing steel with polygonal ferrite and bainite structure with YS: 487–490 MPa, UTS: 566–576 MPa, %EL: 32–34, YS/UTS: 0.84–0.86 and Charpy impact energy of 328–344 J. The properties so achieved have been related to microstructural variations from polygonal ferrite and bainite to acicular ferrite and bainite.

Quenched and tempered steel are broadly classified as low alloy conventional grades with C content of 0.15-0.40% and tool steels with C content as high as 2% alloyed with strong carbide forming elements such as Cr, V, Mo etc. in the range of 1-12%. In both the cases, steels are used in hardened/quenched and tempered or auto tempered condition for improved toughness, strength and wear resistance. The C content and tempering temperature are optimized based on desired application. However, achieving high strength/hardness along with adequate toughness is a challenge. The chemistry design is one of the important parts of developing these grades. The judicious amount of hardenability elements like Mn, Cr, Mo, B etc. are added for achieving required as quenched hardness while excess addition of these elements will not be cost effective. Optimized austenite grain size before quenching is also key to achieve hardenability as well as toughness. All these points have been reviewed systematically in this paper for the first time as there is no such review available covering all aspect of quenched and tempered grade. Unlike text books or any past review articles, this is a systematic review of quenched and tempered steel which will help in designing suitable chemistry and process parameters for producing different grades of quenched and tempered steel in industrial scale.

Stress-induced sensitization in the heat-affected zone (HAZ) of the 304LN austenitic stainless steel weld at 923 K (650 °C) was evaluated using a thermomechanical simulator (Gleeble 3800) at different stress levels. The simulated sensitization behavior of the HAZ was studied in close approximation of the stress and weld thermal cycle that is generally observed during pulse current gas metal arc welding of the 25-mm-thick section of the 304LN steel. The response to the degree of sensitization, as a function of the type and magnitude of stresses present in the matrix, was established through observations on changes in microstructure, electrochemical properties and hardness measurements. Transmission electron microscopy and selected area diffraction confirm that sensitization occurred and Cr23C6 precipitates formed at grain boundaries. The results indicate that the presence of tensile or compressive stresses, especially above the yield stress of the steel, enhances sensitization.

Single-pass and multi-pass deformation schedules were applied over 973 K to 1323 K (700 °C to 1050 °C) using a Gleeble® thermomechanical simulator to understand the effect of the number of deformation passes, strain per pass, and interpass interval on ferrite grain refinement, particularly for the formation of an ultrafine ferrite grain structure (ULFG) with favorable high-angle grain boundaries and texture components. The microstructure, texture, and grain boundaries were characterized using SEM and EBSD. In the single-pass schedule, a decrease in deformation temperature from 1323 K to 1073 K (1050 °C to 800 °C) refined the ferrite grain size from 9.5 to 2.0 μm and intensified the beneficial γ-fiber (〈111〉//ND) texture. The ferrite grain size remained unchanged, whereas Cube and Goss texture strengthened with a further decrease in deformation temperature to 973 K (700 °C). For the multi-pass schedule at 1073 K (800 °C), where the total deformation was applied in three successive passes with 10-second interpass time, an ULFG structure was also developed with 2.5 μm grain size. Grain growth during the interpass intervals weakened the texture in the multi-pass deformed samples compared to that of the single-pass deformed samples. The evolution of microstructure and texture has been explained considering that restoration mechanisms (recrystallization, grain growth, and phase transformation) acted during and after deformation. Finally, ferrite grain refinement during different processing schedules was predicted using a simple mathematical approach based on the experimental data, with suggestions for future improvements.

In order to study the influence of composition and thermo-mechanical processing schedule on the kinetics of austenite recrystallization, strain induced precipitation and final microstructural evolution in Nb-microalloyed steels, thermo-mechanical processing simulations have been carried out inside Gleeble® by varying the number of deformation passes (2-pass vs. 6-pass), deformation temperatures (1000–800°C) and inter-pass times. Low-C high-Mn steel (LCHMn) has been found to offer finer ferrite grain size and finer Nb-precipitation which contributed to superior hardness to that steel, compared to high-C low-Mn steel (HCLMn). Among the deformation schedules applied, 6-pass schedule has been found to be superior over 2-pass schedule in terms of precipitation strengthening and hardness. This study also proposes a mathematical framework to explain the effect of composition and processing schedule in Nb-microalloyed steels following Dutta and Sellars approach on precipitation-recrystallization interaction.

The hot deformation behavior of 2101 grade lean duplex stainless steel (DSS, containing ~5 wt pct Mn, ~0.2 wt pct N, and ~1.4 wt pct Ni) and associated microstructural changes within δ -ferrite and austenite ( γ ) phases were investigated by hot-compression testing in a GLEEBLE 3500 simulator over a range of deformation temperatures, T def [1073 K to 1373 K (800 °C to 1100 °C)], and applied strains, ε (0.25 to 0.80), at a constant true strain rate of 1/s. The microstructural softening inside γ was dictated by discontinuous dynamic recrystallization (DDRX) at a higher T def [1273 K to 1373 K (1000 °C to 1100 °C)], while the same was dictated by continuous dynamic recrystallization (CDRX) at a lower T def (1173 K (900 °C)]. Dynamic recovery (DRV) and CDRX dominated the softening inside δ -ferrite at T def ≥ 1173 K (900 °C). The dynamic recrystallization (DRX) inside δ and γ could not take place upon deformation at 1073 K (800 °C). The average flow stress level increased 2 to 3 times as the T def dropped from 1273 to 1173 K (1000 °C to 900 °C) and finally to 1073 K (800 °C). The average microhardness values taken from δ -ferrite and γ regions of the deformed samples showed a different trend. At T def of 1373 K (1100 °C), microhardness decreased with the increase in strain, while at T def of 1173 K (900 °C), microhardness increased with the increase in strain. The microstructural changes and hardness variation within individual phases of hot-deformed samples are explained in view of the chemical composition of the steel and deformation parameters ( T def and ε ).

Isothermal phase transformation study on low-carbon HY 85 steel shows a strong influence of isothermal holding temperature on the nature of phase transformation and resultant microstructure and hardness. Lath martensite along with bainite was the dominant transformed phase when isothermally held at 750 °C. Austenite changed to allotriomorphic ferrite at 700 °C, which remained significantly at 650 °C, to Widmanstätten ferrite and acicular ferrite at 550 °C, to predominantly upper bainite from 500 to 300 °C, and finally changed to lower bainite at 200 °C. In general, prior austenite grain size varied in the range of 22–7.5 µm with a trough at 500 °C. Similarly, hardness also had trough at 500 °C which ranged in the range of 420–270 VHN. ITT diagram developed through analysis of dilation plots revealed four distinct zones over different temperature ranges. Ferrite transformation was observed at 650 °C and has a flat top similar to start of displacive transformation (upper bainite) observed over 600–300 °C.

Uni-axial hot compression tests were conducted at different temperatures(1173-1423 K) and at strain rates of 0.1, 1, 10 and 100/s using Thermo-mechanical Simulator (Gleeble-3500C System) on a 2.7% Si electrical steel to understand the hot workability issues associated with this steel during hot rolling. The flow curves obtained revealed dynamic recovery as the predominant softening mechanism at majority of hot deformation conditions except at lower temperature and high strain rate where work hardening was observed. However, the work hardening was not very prominent due to ferrite structure throughout the hot deformation temperature range established by Thermo-Calc software. Small amount of cementite (pearlite) transformed from austenite along prior ferrite grain was observed due to presence of carbon in excess of 0.02. Strain rate sensitivity varied within a narrow range of 0.18 - 0.21 with rising tendency with an increase in temperature.

Continuous cooling transformation (CCT) diagrams were determined for weld simulated coarse grained heat affected zone (CGHAZ) of Nb-microalloyed and HY 85 steels using a Gleeble®3800 thermo-mechanical simulator. Samples were heated to a peak temperature of 1573K (1300°C) and cooled at different cooling rates from 0.5K/s to 120K/s. Microstructures, hardness, and impact toughness at 223K were determined corresponding to simulated samples of weld CGHAZ thermal cycles. Transformation temperatures AC3, AC1, Bs, Bf, Ms, and Mf were also determined using dilatometric analysis. At slow cooling rates pro-eutectoid ferrite and pearlite were observed in Nb-microalloyed steel and a mixture of bainitic ferrite and granular bainite was observed in HY 85 steel but no pro-eutectoid ferrite was observed. At moderate cooling rates, only bainite was observed in both the steels. At high cooling rates, lath martensite was observed for both the steels. A strong dependence of prior austenite grain size on mechanical properties has been found. A prior austenite grain size of approximately 30μm (80K/s) has shown impact toughness more than 100J and 198J for Nb-microalloyed steel and HY85 steel samples respectively. Based on microstructures, hardness, impact toughness, and transformation temperatures, CCT diagrams for the weld CGHAZ region were determined.

Thermo-mechanical simulation studies using Gleeble System have found extensive application in almost all spheres of metal processing industries including process optimization, development of new alloys, quality/ yield improvement and material characterization, etc. Physical simulation unlike numerical simulation being very close to the real world process can be very helpful in near exact reproduction of the process and in turn better results if carried out carefully. However, it has certain limitations too which must be clearly understood before planning for a study. Therefoere, such studies need to be carried out with precaution to achieve desired results. Otherwise, the simulated results may not find appreciation with actual processing. These limitations can be machine specific or understanding specific. For example, thermal gradient along length is advantageous for HAZ or continuous casting simulation but it limits the scope for hot tensile test due to low uniform temperature zone across gauge length. Similarly, most of the research papers published on hot compression to understand the hot workability or development of processing map are based on on-heating experiments involving heating the material to deformation temperature followed by deformation at different strain rate and temperature. The results generated are sometime used to optimize an industrial process which involves different thermal cycle of reheating the material to high temperature, soaking followed by cooling to deformation temperature and are unable to produce desired results.

The correlation of microstructure and mechanical properties in simulated heat affected zone (HAZ) of a low carbon bainitic steel plate of thickness 28mm using single and multiple thermal cycles was investigated in the Gleeble 3800 Thermo Mechanical Simulator. Optical microscopy, field emission scanning electron microscopy, hardness, and impact strength measurements were done to characterize theweld HAZ simulated steel samples. Peak temperatures (Tp) of 1300, 1150, 1000, 900, 800, 700, and 600 degrees C with heat input 50 kJ/cm were used for single pass weld. In two pass weld cycles, peak temperature (Tp1) 1300 degrees C, and (Tp2) of 1100, 1000, 900, 800, and 700 degrees C were used. This heat input is in line with the submerged arc welding (SAW) process extensively used in the fabrication of ship building industries. The impact toughness of weld HAZ simulated specimens was determined at -50 degrees C by using a Charpy impact tester. Best impact toughness values (minimum 75 J) in weld HAZ simulated specimen were observed at the peak temperatures from 600 to 1150 degrees C in single pass weld and from 1000 to 1100 degrees C in two pass weld HAZ thermal cycles.

Thermo-mechanical simulation studies can be effectively utilized for optimization of processing parameters apart from development of new alloys, quality/yield improvement and material characterization. Physical simulation, being very close to the real world process, can be very helpful in near exact reproduction of the process, and in turn, better results. Thermo-mechanical simulation studies using Gleeble System found extensive applications in steel research and its processing. It can help in careful design of alloy chemistry, proper continuous casting operation to produce defect-free casting, and optimization of hot rolling and post-cooling parameters to produce the desired microstructure and annealing process after cold rolling to achieve the desired microstructure and properties, welding for easy fabrication, etc. Each of these steps needs to be fine-tuned and optimized to achieve the maximum benefit towards reduction in alloy additions, as well as quality and yield improvement during steel processing. A number of studies like continuous casting simulation for production of Cr-alloyed rail steel, hot deformation simulation and phase transformation behavior to optimize hot rolling of difficult to process high boron steel, and hot deformation simulation to bring down the rolling load and annealing simulation to achieve the desired hardness in low nickel stainless steel, etc. undertaken, helped to improve the processing of these steels. Details of these studies, results obtained, and the way to improve processing were discussed.

In this paper, Mechanical properties of areca fibers extracted from areca husk are determined. Further these Areca fibers were chemically treated and the effect of this treatment on fiber strength is studied. Areca fiber composite laminates were prepared with randomly distributed fibers in wood powder and Phenol Formaldehyde. Composite laminates were prepared with different proportions of phenol formaldehyde and fibers. Tensile test, moisture absorption test, and flexural (three-point bending) tests on these laminates were carried out. Properties of these areca-reinforced phenol formaldehyde (PF) composite laminates were analyzed and observed that composite plate of 300ml resin shows the maximum tensile strength, composite plate of 400ml PF shows the maximum bending stress and a composite plate of 500ml PF shows better moisture absorption resistance.

The microstructure of an austenitic SS 304L rapidly quenched from its semi-solid state shows a unique annular austenitic ring in between the core of each globule and its ferritic outer layer. On the basis of experimental results and microstructural analysis, it is proposed that the ring is formed as a result of preferential austenitic phase nucleation in a small quantity of liquid entrapped between adjacent solid globules during rapid quenching, in spite of the fact that ferrite is the thermodynamically stable phase for the alloy.

Micro-alloyed (MA) forging steels are becoming increasingly important economic alternative to the traditional quenched and tempered steels. MA steels do not require heat treatment after they are shaped into parts, as the required mechanical properties are obtained directly at the end of the process and save the cost and energy by reducing the number of operations. Also, these steels have achieved very good characteristics of toughness and weldability. These beneficial properties have been achieved by a careful control of chemical composition and by adopting suitably controlled thermo- mechanical processes. In this study, hot compression test on a medium carbon vanadium micro-alloyed steel grade 38MnVS6 has been performed on Gleeble-Thermo mechanical Simulator (TMS) in order to study the effect of forging temperature and strain rate on flow stress. Also the proposed process has been simulated using a forging process simulation software tool, DEFORMTM 3D V6.1.