Properties Of Steel Research Articles

The Influence of Multi-Pass Friction Stir Processing on the Microstructure Evolution and Mechanical Properties of IS2062 Steel

The motive of present work is to explore the variation in the material characteristics of steel upon multi-pass friction stir processing. Steel plates (IS2062) that were 3 mm thick, were subjected to friction stir processing in a multi-pass manner. The selected transverse speed was 150 mm/min, along with a tool rotation of 800 RPM when using a tungsten carbide tool (shoulder diameter—10 mm). Steel plates were processed using the single-pass, double-pass, and triple-pass travel of the rotating tool to observe the impact of multi-pass processing on the properties of steel plates. Multi-pass friction stir processing resulted in a higher micro-hardness of 175 VHN after the second pass, in comparison to the unprocessed metal, which had a micro-hardness of 130 VHN, owing to the collective effect of the plastic flow of the material due to the rotation of the tool and frictional heat, which also leads to grain refinement. The second pass evidenced an average grain size of 22 microns, whereas the unprocessed material had an average grain size of 57 microns. The results of EBSD and SEM characterization showed reasonably improved material properties of the processed work materials.

Effect of cold rolling route and annealing on the microstructure and mechanical properties of AISI 316 L stainless steel

Since cross rolling promotes the transformation of austenite to deformation-induced α΄-martensite and increases the dislocation density in the retained austenite, the reversion/recrystallization annealing after cross rolling might be more effective to achieve finer grain sizes in metastable austenitic stainless steels. Accordingly, the effect of cold rolling route and annealing for grain refinement and improvement of mechanical properties of AISI 316 L stainless steel was systematically investigated in the present work. It was found and formulated that by increasing strain, the grain refinement efficiency during annealing is improved, the effect being more pronounced if the cold rolling step is applied by cross rolling instead of unidirectional rolling. The evaluation of tensile properties revealed that all cold rolling and annealing routes lead to significant improvements of mechanical properties in terms of strength and plasticity, the influence of cross rolling being more prominent again. Moreover, the cross rolling and annealing route led to a remarkable strength-ductility balance, which revealed the opportunities that this route can offer for the improvement of mechanical properties of austenitic stainless steels. Accordingly, the results of the present work may shed light on the further utilization of cold rolling route and annealing treatment.

Influence of the Machining Process on the Wear Properties of Self-Mated Structural Steel in Dry Sliding Conditions

This work investigates the tribological behavior of a machined S355JR structural steel in dry sliding conditions for the development of an innovative seismic dissipation system. Flat-ended pins and disks were made of the same structural steel to simulate the conformal contact of different device parts. Pins were machined by turning, while disks were milled and turned to obtain a nominal average surface Ra roughness ranging from 0.8 µm to 6.3 µm. The influence of the surface roughness on the coefficient of friction (COF), specific wear rate (SWR), and time to steady-state (TSS) was investigated. Tribological tests were conducted reciprocating motion in dry sliding conditions to simulate the operating conditions of the device, with 1 Hz and 2 Hz reciprocating frequencies and an applied normal load of 50 N. The Rsk and Rku roughness parameters helped to better understand the tribological response of milled and turned disks, having an influence on the TSS and SWR.

Effect of Si Content on Microstructure and Properties of Low-Carbon Medium-Manganese Steel after Intercritical Heat Treatment

Effect of Si Content on Microstructure and Properties of Low-Carbon Medium-Manganese Steel after Intercritical Heat Treatment

Effects of Mn, Al, and Cu on Austenite Stability and Corrosion Properties of High Cr-Equivalent Steels

Effects of Mn, Al, and Cu on Austenite Stability and Corrosion Properties of High Cr-Equivalent Steels

The influence of annealing temperature on the microstructure and mechanical properties of Fe-0.52 C-11Mn-5.14Al-1Cr lightweight steel

Steel used in the automotive industry must strike a delicate balance between strength and ductility to maintain the structural integrity of vehicles and achieve intricate designs. Traditional methods of reducing weight by using high-strength low-carbon steels have limitations. As a result, a new dual-phase lightweight steel with an austenite-ferrite structure and the composition Fe-0.52 C-11Mn-5.14Al-1Cr was developed. The relationship between the microstructure and mechanical properties of this lightweight steel, which underwent various annealing processes (700°C-1000°C) after cold rolling, was examined using specialized equipment like a universal testing machine, electron microscopy, and X-ray diffractometer. The findings reveal that the cold-rolled test steel (CR) exhibits high tensile strength (1500 MPa) but low elongation at break (3.9 %). The performance of the experimental steel post-annealing treatment has shown significant improvement, with the average grain size increasing with higher annealing temperatures. The γ phase generally shows an increasing trend, with finer grains post-annealing, and the distribution of the α phase displays a consistent pattern along γ boundaries. Additionally, a substantial number of annealing twins appear in the matrix. These twin boundaries absorb some dislocations, and slip leads to the movement of twin boundaries, effectively reducing stress concentration from deformation and enhancing the ability of twin boundaries to accommodate plastic strain, creating twin dislocation interaction. The interplay among dislocations, stacking faults, and twins regulates the balance between strength and plasticity. Following treatment at 850°C × 1 min + 500°C × 3 min, the steel displays excellent mechanical properties, including ultimate tensile strength (836 MPa), elongation (53 %), and strength-ductility product (43,723 MPa·%). This study identifies a specific heat treatment parameter that achieves a harmonious equilibrium between outstanding strength and plasticity (strength-ductility product) within the designed composition.

Study of Quenching and Partitioning (Q&P) and Ultrasonic Surface Rolling (USR) Process on Microstructure and Mechanical Property of a High-Strength Martensitic Steel.

Steel with a combination of strength and plasticity is prevalently demanded for lightweight design and emission reductions in manufacturing. In this study, a high-strength Cr-Ni-Mo martensitic steel treated by quenching and partitioning (Q&P) and ultrasonic surface rolling (USR) processes was studied for both strength and plasticity enhancement. Specimens were austenitized at 850 °C and then quenched to 240 °C via cooling by water, oil, and normalization in quenching. This was followed by partitioning, in which two groups of specimens were heated to 370 °C and 350 °C for 45 min, respectively. At last, all the specimens were quenched to room temperature with the same methods of quenching. The highest tensile strength increased from 681.73 MPa to 1389.76 MPa when compared to as-received (AR) steel after the Q&P process. The USR process with a static force of 800 N further improved the tensile strength of specimens with high tensile strength after the Q&P process, which improved from 1389.76 MPa to 1586.62 MPa and the product's strength and elongation (PSE) increased from 15.76 GPa% to 15.9 GPa%, while the total elongation showed a mitigatory decrease from 11.34% to 10.02%. Tensile fractures were also studied and verified using a combination of strength and plasticity after a combined process of Q&P and USR.

Influence of water radiolysis on the passive properties of 316L-stainless steel.

This work aims to study the effect of radiolytic species induced by water radiolysis on the passive behavior of 316L stainless steel. For this purpose, the stainless steel/neutral and aerated 0.02 M Na2SO4, electrolyte solution interface was irradiated with proton beams. A wide range of energies between 2 and 16 MeV was selected, varying the maximum of the energy deposition between 0.5 and 122 µm in water from the interface. The irradiation experiments were performed at the CEMHTI cyclotron in Orléans and the 4 MV Van de Graaff accelerator at IP2I in Lyon (France). A dedicated irradiation device implemented with a 3-electrode cell dedicated to perform electrochemical measurements allows to measure the surface reactivity of the stainless steel as a function of the irradiation conditions. Results show that whatever the beam energy, the corrosion potential remains unchanged. It indicates that the very short-lived, highly reactive radiolytic species drive the corrosion potential and not only the recombination products such H2O2 or H2. The stainless steel remains in the passive state whatever the irradiation conditions. However, it is shown that, during irradiation, the passive film is less protective. This evolution is attributed to radiolysis of bound water molecules in the passive film.

Deep Rolling Techniques: A Comprehensive Review of Process Parameters and Impacts on the Material Properties of Commercial Steels

The proposed review demonstrates the effect of the surface modification process, specifically, deep rolling, on the material surface/near-surface properties of commercial steels. The present research examines the various process parameters involved in deep rolling and their effects on the material properties of AISI 1040 steel. Key parameters such as the rolling force, feed rate, number of passes, and roller geometry are analyzed in detail, considering their influence on residual stress distribution, surface hardness, and microstructural alterations. Additionally, the impact of deep rolling on the fatigue life, wear resistance, and corrosion behavior of AISI 1040 steel is discussed. Engineering components manufactured by AISI 1040 steel can perform better and last longer when deep rolling treatments are optimized with an understanding of how process variables and material responses interact. This review provides critical insights for researchers and practitioners interested in harnessing deep rolling techniques to enhance the mechanical strength and durability of steel components across diverse industrial settings. In summary, the valuable insights provided by this review pave the way for continued advancements in deep rolling techniques, ultimately contributing to the development of more durable, reliable, and high-performance steel components in diverse industrial applications. The establishment of generalized standardizations for the deep rolling process proves unfeasible because of the multitude of controlling parameters and their intricate interactions. Thus, specific optimization studies tailored to the material of interest are imperative for process standardization. The published literature on the characterization of surface and subsurface properties of deep-rolled AISI 1040 steel, as well as process parameter optimization, remains limited. Additionally, numerical, analytical, and statistical studies and the role of ANN are limited compared with experimental work on the deep rolling process.

Permeability and strength of gradient printed permeable steel manufactured by selective laser melting

Based on the forming principle of laser rapid melting and layered manufacturing, the selective laser melting (SLM) process is suitable for the preparation of permeable metal materials with a certain porosity. One of the important applications of this special structure is the development of permeable steel. In this study, the permeable steel with micron-sized controllable pores was prepared by gradient printing using SLM process. The formation and connectivity mechanism of pore structure were analyzed by adjusting the interlayer arrangement of scanning melt channels, and the influence of process parameters on the pore characteristics, permeability and mechanical properties was systematically investigated. The results revealed that the porosity and pore size of permeable steel were effectively improved by controlling the hatch distance and scanning strategy, with the results ranging from 7.81 % to 17.32 % and 57 μm to 121 μm, respectively. Based on the gas permeation test, it was verified that the permeability of permeable steel showed a clear upward trend with increasing porosity, and the results ranged from 2.17 × 10−12 m2 to 4.26 × 10−12 m2, indicating that the pore structure provides a strong basis for gas flow. Moreover, the mechanical properties of permeable steel decreased significantly with the increase of porosity and pore size, and the compressive strength and tensile strength ranged from 1061 MPa to 528 MPa and 1018 MPa to 609 MPa, respectively. The mechanical behavior and deformation mechanism were closely related to the gradient evolution of the pore structure. Overall, the gradient printed permeable steel using SLM process has good permeability and mechanical properties.

Effect of N plasma immersion ion implantation (N-PIII) on the microstructure and mechanical properties of 8Cr4Mo4V steel

To enhance the surface hardness and wear resistance of 8Cr4Mo4V steel, nitrogen plasma immersion ion implantation (N-PIII) was carried out, under various nominal implantation energies, in this study. Additionally, the microstructure and mechanical properties of the steel were analyzed. The results indicated that the depth of the nitrogen ion-implanted layer escalated with the specified implantation energy, reaching 140 nm for a 50 keV sample. Nitrogen was present within the implanted layer in the martensite lattice as a solute, and also in the form of nitrides along with alloying elements. Moreover, a nanocrystalline layer approximately 40–70 nm thick also formed at the sample surface. As the implantation energy increased, both the surface roughness and residual stress of the sample initially increased before declining, whereas the surface hardness and modulus exhibited a gradual increase. After the 50 keV N-PIII treatment, the surface hardness of the sample increased by 39 %, which caused a remarkable reduction in the friction coefficient, and the wear amount was also reduced by about 40 %. This work systematically establishes the relationship between the surface microstructures, surface morphology, and mechanical properties of implanted 8Cr steel, and significantly improves its surface hardness and wear resistance.

Effect of Y2Ti2O7 on microstructure and tensile properties of ODS-CLAM steel

Nano-Y2Ti2O7 is one of the phases used for improving the strength of oxide dispersion strengthened (ODS) steels, which is usually precipitated with Ti and Y2O3 added. The effect of synthesized Y2Ti2O7 on China low activation martensitic (CLAM) steel was studied. Two kinds of ODS-CLAM samples with nano-Y2Ti2O7 and amorphous Y2Ti2O7 additions were prepared using mechanical alloying (MA) and spark plasma sintering (SPS). The results indicates that amorphous Y2Ti2O7 powders had both amorphous and crystal oxides after milling with CLAM powders. Y2Ti2O7 powders were refined to below 10 nm in size with almost no structural change, and randomly distributed in the matrix. The initial size of added Y2Ti2O7 had a smaller impact on the size of precipitates, and the initial structure or the transform of the oxides during milling process were more important. The added Y2Ti2O7 particles were refined from ∼32 nm to 9.2 nm in size, while the size of amorphous Y2Ti2O7 particles was reduced from micron size to 6.9 nm in the sintered sample. The structure of Y2Ti2O7 in ODS powders affected the microstructure and strength of the sample after sintering. The sample with Y2Ti2O7 had higher strength and lower plasticity at both room temperature and 650 °C because of the higher dislocation density, while the sample with amorphous Y2Ti2O7 had higher plasticity with almost the same yield strength due to its higher dispersion strengthening. This study reveals the changes in Y2Ti2O7 structure during preparation process and suggests that the expected properties of ODS steels can be obtained by controlling the oxide structure.

Effects of homogenization and deep cryogenic treatments on microstructure and mechanical property of D2 tool steel fabricated by laser direct energy deposition

The integration of laser direct energy deposition (L-DED) for manufacturing high-hardness D2 tool steel components presents a promising avenue for addressing the increasing complexity of product geometries demanded by modern industry. However, the inherent variability in microstructure and mechanical properties induced by L-DED across the build height necessitates the employment of post-processing techniques to achieve material homogeneity. This study explores the synergistic application of homogenization and deep cryogenic treatment (DCT) as a novel post-processing strategy aimed at mitigating microstructural inhomogeneities and enhancing the mechanical properties of L-DED-fabricated D2 tool steel. Initial analysis of the as-built samples revealed a microstructure characterized by a fine network of eutectic carbides enveloping an FCC matrix, which imposed constraints on martensite transformation during DCT. Homogenization was found to effectively alleviate these constraints, promoting compositional and microstructural uniformity and enabling a more consistent transformation to martensite across the samples upon subsequent DCT. The strategic combination of homogenization and DCT resulted in achieving uniformly distributed high hardness levels exceeding 750 HV throughout the entire sample, regardless of their initial positions within the build. This study demonstrates the potential of combining homogenization with DCT as an effective approach to enhance the structural integrity and mechanical performance of L-DED-fabricated D2 tool steel, offering valuable insights for the development of advanced manufacturing processes for alloyed materials.

Effect of tempering temperatures on microstructure and mechanical properties of high-strength steel

Effect of tempering temperatures on microstructure and mechanical properties of high-strength steel

In Situ Study of Precipitates' Effect on Grain Deformation Behavior and Mechanical Properties of S31254 Super Austenitic Stainless Steel.

Grain boundary (GB) precipitation-induced cracking is a significant issue for S31254 super austenitic stainless steel during hot working. Investigating the deformation behavior based on precipitate morphology and distribution is essential. In this study, continuous smaller and intermittent larger precipitates were obtained through heat treatments at 950 °C and 1050 °C. The microstructure evolution and mechanical properties influenced by precipitates were experimentally investigated using an in situ tensile stage inside a scanning electron microscope (SEM) combined with electron backscatter diffraction (EBSD). The results showed that continuous precipitates at 950 °C had a stronger pinning effect on the GB, making grain rotation difficult and promoting slip deformation in the plastic interval. Continuous precipitates caused severe stress concentration near GB and reduced coordinated deformation ability. Additionally, the crack propagation path changed from transcrystalline to intercrystalline. Furthermore, internal precipitates were a crucial factor affecting the initial crack nucleation position. Interconnected precipitates led to an intergranular fracture tendency and severe deterioration of the material's plasticity, as observed in fracture morphology.

Effects of Initial Grain Orientation and Annealing Parameters on Grain Size, Texture, and Magnetic Properties of Ultra-Thin Grain-Oriented Silicon Steel

Effects of Initial Grain Orientation and Annealing Parameters on Grain Size, Texture, and Magnetic Properties of Ultra-Thin Grain-Oriented Silicon Steel

Modeling 3D finite element analysis of a semi-elliptical crack on stress corrosion cracking of API X52 pipeline

In this study, an external semi-elliptical crack was modeled in a 3D API 5 L X52 pipeline with stress corrosion cracking (SCC). To make the crack, the finite element method (FEM) was used to obtain the failure pressure (Pf) and its mechanical behavior. The longitudinal crack had a constant length (2c) and varied with depth (a). The properties of X52 steel subjected to SCC using the slow strain rate technique (SSRT) were considered. True stress-strain curves were obtained in air and in an NS4 solution with pHs of 3.5 and 9.5 at temperatures of 25 and 50°C. According to the SCC index calculated from the mechanical properties of the SSRT, the X52 steel is susceptible to SCC at pH 3.5 and 50°C. The mechanical properties of the tensile test using the stress-strain curves decreased as the pH and temperature changed, compared to those carried out at room temperature. This was due to the corrosion and hydrogen embrittlement produced by the solution on the X52 steel. The failure pressure is sensitive to the stress-strain curve; if the stress-strain curve decreases, the failure pressure also decreases. Corrosion defects, such as longitudinal cracks in X52 steel, which could be susceptible to SCC in an NS4 solution, decrease the failure pressure (Pf) and its capacity to withstand pressures of up to 75% in pipe-grade steel that transports hydrocarbons.

Effect of gradient nanostructures on the damage mechanism of aermet100 steel at various strain rates

The introduction of nano-scale grains, which form a gradient nanostructure (GNS) within the material, usually increases the service life of metallic materials. In this study, the uniaxial tensile mechanical properties of AerMet100 steel in initial and GNS states under different strain rate conditions were compared, and the microanalysis of tensile fracture was performed. It is found that GNS has little effect on the mechanical properties of AerMet100 but has an effect on its damage mode. The initial AerMet100 was basically ductile fracture, and GNS increased the brittle fracture mode in AerMet100.

Optimizing the Microstructure and Properties of Fe–Ni–Cu–Mo–C Sintered Steel by TiB2

The Fe–Ni–Cu–Mo–C powder metallurgy sintered steels with TiB2 reinforced were prepared by the conventional powder metallurgy techniques. This study explored the influence of incremental TiB2 additions, ranging from 0.1 to 0.6 wt.%, on the microstructure and properties of these steels. The results reveal that the microstructures primarily consist of martensite, Ni-rich austenite, Cu-rich pearlite, TiB2, and Ti–O rich nanoparticles. The latter form via a reaction between TiB2 and free oxygen. Notably, both the density and impact strength of the steels showed enhancement with increasing TiB2 content. The optimal values, 7.25 g/cm3 for density and 17.23 J/cm2 for impact strength, were observed at a TiB2 concentration of 0.5%. The hardness and ultimate tensile strength also increased steadily, reaching maxima of 38.7 and 1083.7 MPa at 0.6% TiB2, respectively. However, excessive TiB2 led to the formation of a net-like B-containing eutectic network, adversely affecting the steel properties. Steels with 0.5% TiB2 exhibited excellent wear resistance. At 200 rpm, the dominant failure mode was abrasive wear, which shifted to adhesive wear with oxidation at 400 rpm, followed by abrasive wear.

Microstructure and mechanical properties of the laser welded air-hardening steel joint

The decrease in mechanical properties of high-strength steel after welding is an important issue affecting the wide application of high-strength steel. Air-hardening steel is a high-strength steel suitable for lower body structural parts such as subframes. Its application process involves welding, hot forming and other processes. The present work investigates the microstructure and mechanical properties of the air-hardening steel laser welded joint that is air-cooled after hot forming in the two-phase zone (800 °C). The microstructure was characterized by electron backscattered diffraction (EBSD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that during hot forming, the welded joint transforms from martensite to ferrite and acicular martensite, and the base metal transforms from ferrite to polygonal martensite and ferrite. The difference in martensite morphology between the welded joint and the base metal is attributed to the nucleation positions of austenite. The structural evolution of the welded joint and the base metal is accompanied with the annihilation and reproduction of dislocations, which results in significant changes in hardness. The hardness value dropped from the highest 430 HV to 271 HV in the welded joint, while increased from the lowest 184 HV to 203 HV in the base metal. After hot forming, the tensile strength of the welded sample is reduced by only 36 MPa, and the total elongation is slightly decreased by about 1.5% compared with the unwelded sample. The welded joint and the base metal have similar plastic deformation capabilities, since the acicular martensite in the welded joint displays good plastic deformation ability, and the dislocation density of the welded joint and the base metal is similar. Overall, the microstructure and dislocation density of the air-hardening steel welded joint after hot forming are similar to those of the base metal, which is responsible for the good mechanical properties of air-hardening steel welded joint.