Effect Of Heat Treatment Process Research Articles

Effect of heat treatment process on microstructure and properties of copper modified 1Cr11MoNiW1VNbN

Abstract The purpose of this study was to investigate the effects of Cu element content and heat treatment process on the microstructure and mechanical properties of 1Cr11MoNiW1VNbN martensitic heat-resistant steel. Microstructure was characterized by optical microscope (OM) and scanning electron microscope (SEM), tensile testing machine and impact testing machine were used to test the mechanical property. The results show that with the increase of Cu content, the precipitation of Cu-rich phase in the steel increases, while the formation of δ-ferrite and coarse carbides decreases, which significantly improves the strength of the material. When the Cu content is 2.14%, the tensile strength at 600 °C reached 542 MPa and the yield strength reached 484 MPa after normalizing at 1000 °C and tempering at 700 °C. With the increase of the normalizing temperature, the strength of the test steel decreases slightly, and the impact energy improved significantly.

Effect of Heat-Treatment Process on Magnetic Characteristics of Grain-Oriented Electrical Steel

This paper explores the effects and impacts of the metallurgical process of quenching on grain-oriented strips of electrical steel. Experimental findings reveal that quenching resulted in increased hardness and an increased Young’s modulus. An analysis of the material structure post-quenching indicates significant alterations in grain spacing and reduced height differences between grains. However, the magnetic properties of the steel deteriorated following quenching.

Effect of heat treatment processes on the microstructure and mechanical properties of 00Cr13Ni5Mo super martensitic stainless steel (SMSS)

The effects of quenching and tempering temperatures on the microstructure and mechanical properties of super martensitic stainless steel (SMSS) 00Cr13Ni5Mo were studied. The SMSS after heat treatment is composed of martensite (α phase) and a small amount of austenite. When the quenching temperature is 930 °C, with the increase of tempering temperature, the enrichment of Ni in martensite leads to the formation of reverse austenite, the content of martensite phase decreases from 84.9 % to 80.0 %, and the average grain size increases from 23.23 μm to 27.07 μm. When tempering at 580 °C, the content of martensite phase decreases from 80.0 % to 83.7 % with the increase of quenching temperature. The average grain size increased from 25.23 μm to 35.01 μm. When the quenching temperature is 930 °C, the hardness and yield strength of SMSS decrease, and the hardness and yield strength are the highest at 530 °C, which are 275 HV and 873 MPa. The plasticity increases first and then decreases, and the plasticity is the best at 580 °C. The elongation and reduction of area were 22.87% and 71.41%. These changes in mechanical properties are mainly related to the content of martensite and reversed austenite in the microstructure. The tensile strength and elongation of SMSS under different process conditions were compared. The results show that when the quenching temperature is 930 °C and the tempering temperature is 580 °C, the comprehensive performance of SMSS is the best, reaching 18700 MPa•%. This value is 31% higher than that of forgings. Finally, the formation mechanism of reversed austenite was discussed, and the strengthening model of SMSS 00Cr13Ni5Mo was established.

Study on precipitation in (CoCrFeMnNi)90Al6Ti4 high entropy alloy

(CoCrFeMnNi)90Al6Ti4 high entropy alloy (HEA) was prepared by adding Al and Ti elements into CoCrFeMnNi HEA. The alloy underwent processes including copper mold suction casting, 1473 K homogenization, 30 % cold rolling + 1273 K annealing + 1073 K aging, and water quenching and heating treatment. Microstructure and phase composition of both as-cast and heat-treated (CoCrFeMnNi)90Al6Ti4 HEA were studied using metallographic microscope, scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffractometer (XRD), and transmission electron microscope (TEM). The effect of heat treatment processes on the precipitation of second phases in (CoCrFeMnNi)90Al6Ti4 HEA was investigated, and mechanical properties of as-cast and heat-treated (CoCrFeMnNi)90Al6Ti4 HEA were studied via hardness tests. The results show that in as-cast (CoCrFeMnNi)90Al6Ti4 HEA, the second phase precipitated is primarily L21 structured AlTiNi2 phase. After homogenization, cold rolling, annealing, and aging processes, both the quantity and size of the second phase increase, with a small amount of nanoscale L12 phase appearing after aging treatment. With the progression of heat treatment, the hardness of (CoCrFeMnNi)90Al6Ti4 HEA increases, and mechanical properties are improved.

The influence of heat treatment process on the dynamic recrystallization evolution mechanism of Inconel 718 during high-speed machining

This study aims to investigate the cutting mechanisms of Inconel 718 alloy under different heat treatment processes and the grain refinement patterns of the transformed layer. By establishing a constitutive model suitable for cutting and importing it into DEFORM-3D for heat treatment processing and single-factor cutting experiment simulation, the effects of heat treatment processes and cutting parameters on cutting force, cutting temperature, and surface grain refinement were studied. The results indicate that the increase in cutting force is maximum, approximately 12 %, after the aging temperature is raised from 668 °C to 718 °C. The cutting force generated after aging heat treatment shows a negative correlation with cutting speed, whereas the cutting force after solution heat treatment rises significantly between 1400 and 1600 mm/s. The maximum cutting temperature occurs in workpieces after solution heat treatment, about 112 % of that of workpieces treated at 718 °C aging heat treatment. At the onset of cutting, the size relationship of the original grain volume is as follows: untreated < solution heat treatment < aging heat treatment; the number of nucleation points for dynamic recrystallization at grain boundaries is as follows: aging heat treatment < solution heat treatment < untreated. The most significant increase in the number of dynamic recrystallizations is observed after aging heat treatment at 621 °C, with the relationship of the number of recrystallizations in different cutting deformation zones being: secondary deformation zone < primary deformation zone < tertiary deformation zone. With the increase in cutting depth, the grain size of the workpiece after solution heat treatment first increases then decreases during the cutting process; the grain size of the workpiece after aging heat treatment first decreases then increases. The grain size of the workpiece during the cutting process after heat treatment is negatively correlated with cutting speed. Specifically, when the cutting speed is 600 mm/s, the grain size after solution heat treatment is the largest, about 1.1 times that of the 718 °C aging heat-treated workpiece.

Effect of heat treatment processes on the Cu-electrodeposited through glass vias (TGV) plate

Based on laser-induced deep etching technology and through-hole filling techniques, TGV interposers were successfully fabricated. The residual stress in the Cu overburden film directly affects the yield improvement after subsequent grinding of the interposer. Therefore, we studied the evolution of residual stress, microstructural changes, and micro-nano mechanical properties within the Cu overburden film after heat treatment at different temperatures. Residual stress analysis using the sin2Ψ method with an X-ray diffractometer (XRD) indicates that during the process of increasing temperature from 100°C to 200°C, the internal residual stress in the Cu overburden film changes from compressive stress to tensile stress. Furthermore, the maximum absolute value of the residual stress, 70.09 MPa, appears at room temperature, and the minimum absolute value of the residual stress, 15.59 MPa, occurs after the heat treatment process at 200°C. Electron backscatter diffraction (EBSD) microstructural analysis shows that the application of heat treatment can effectively accelerate static recrystallization (SRX), promote a higher proportion of high-angle grain boundaries (HAGB), and refine grain size. Additionally, a (001) preferred orientation at high residual stress states and a (111) preferred orientation at low residual stress states are observed. Nanoindentation test results indicate that the Cu overburden film treated at 100°C has the most potential for removal during the grinding process.

Interpretable Predicting Creep Rupture Life of Superalloys: Enhanced by Domain-Specific Knowledge.

Evaluating and understanding the effect of manufacturing processes on the creep performance in superalloys poses a significant challenge due to the intricate composition involved. This study presents a machine-learning strategy capable of evaluating the effect of the heat treatment process on the creep performance of superalloys and predicting creep rupture life with high accuracy. This approach integrates classification and regression models with domain-specific knowledge. The physical constraints lead to significantly enhanced prediction accuracy of the classification and regression models. Moreover, the heat treatment process is evaluated as the most important descriptor by integrating machine learning with superalloy creep theory. The heat treatment design of Waspaloy alloy is used as the experimental validation. The improved heat treatment leads to a significant enhancement in creep performance (5.5 times higher than the previous study). The research provides novel insights for enhancing the precision of predicting creep rupture life in superalloys, with the potential to broaden its applicability to the study of the effects of heat treatment processes on other properties. Furthermore, it offers auxiliary support for the utilization of machine learning in the design of heat treatment processes of superalloys.

Microstructure and corrosion resistance properties of (FeCoNi)86Al7Ti7 high-entropy alloy via different aging time

The effects of heat treatment processes with different aging times on the corrosion behavior and passive film properties of the (FeCoNi)86Al7Ti7 high-entropy alloy were investigated. The study shows that aging time has a significant effect on the grain characteristics and L21 phase distribution. A suitable aging time optimizes the compositional segregation between the face-centered cubic and L21 phases. Samples aged for 1 h exhibit the best corrosion resistance, which can be attributed to the homogeneity of the composition and the quality of the passive film. Ti oxides play a major role in the passive film.

Effect of Heat Treatment Process on Microstructure and Mechanical Properties of High-Carbon H13 Steel

This paper investigated the mechanical properties and microstructures of different samples of H13 steel after they underwent various heat treatment processes. It provided a detailed analysis of the microstructure and mechanical properties under different processes and approached the topic from a theoretical perspective. The phase composition of each sample remained unchanged after undergoing different heat treatment processes. Despite the vacuum gas quenching (H1) sample being guaranteed a hardness of 58.47 HRC, its toughness fell below expectations at a mere 46.75 J. Notably, the microstructure of the sample which underwent the H1 process and the cryogenic (H2) treatment exhibited a finer grain size and higher toughness compared to the sample which only underwent the H1 process without the cryogenic treatment. Its toughness was 70.19 J, but its hardness slightly decreased to 57.47 HRC. Following the application of oil quenching and cryogenic treatment (H3), the hardness of the sample significantly increased, reaching a remarkable 58.38 HRC. Additionally, the sample exhibited good impact resistance, with a measurement of 74.25 J. Before the H2 process, the sample which underwent the spheroidizing annealing process (H4) had a higher hardness compared to the sample without spheroidizing annealing. At the same time, when comparing the above four samples, the sample that underwent the H4 process exhibited the best toughness, with a value of 86.94 J, while still maintaining a hardness of 57.85 HRC; thus, it achieved an ideal balance between strength and toughness. Therefore, the optimal heat treatment process for high-carbon H13 steel was spheroidizing annealing followed by vacuum gas quenching and then cryogenic treatment.

Effects of heat treatment processes on the mechanical properties, microstructure evolution, and strengthening mechanisms of Al–Mg–Zn–Cu alloy

In this study, the mechanical properties and strengthening mechanisms resulting from the evolution of microstructure in an Al-4.39Mg-2.78Zn-0.42Cu (wt%) alloy were investigated through various heat treatment processes. Compared with the conventional T6 process, both the final thermomechanical treatment (FTMT) and the T6+deformation (T6D) process were found to significantly increase the strength of the alloy. In FTMT and T6D treated alloys, the distribution of nano-sized T-Mg32(Al, Zn, Cu)49 phase and dislocations were observed throughout the microstructure. Furthermore, the FTMT process led to a decrease in the solid solution amount of Mg atoms in the alloy, resulting in an improvement of the Portevin-Le Chatelier (PLC) effect. The increase in yield strength of the FTMT-treated and T6D-treated alloys was attributed to the combined effects of enhanced precipitation strengthening and introduced dislocation strengthening. However, the contributions of grain boundary strengthening and solid solution strengthening remained relatively unchanged. This study presents a strategy for producing Al–Mg–Zn–Cu alloys with excellent mechanical performance by manipulating their microstructure and strengthening mechanisms.

Effect of Heat Treatment Processes on the Microstructure and Mechanical Properties of High-Strength Aluminum Alloy Deposited Layers Processed by Fused Arc Additive Manufacturing.

In this study, 7075 aluminum alloy welding wire with TiB2 nanoparticle reinforcement as an additive together with the variable polarity TIG welding arc as a heat source were applied to produce thin-walled deposited layer samples. Results indicated that the performance of the deposited structure of 7075 aluminum alloy with a TiB2 reinforcement phase was significantly improved compared to the deposited structure of ordinary 7075 aluminum alloy welding wire. Meanwhile, the precipitation of the TiB2 reinforcement phase was insufficient within the structure, and the enhancing effect could not be fully exerted. Moreover, the 7-series aluminum alloy contained a large amount of Zn and Mg elements inside. If the soluble crystalline phase was not fully dissolved, severe stress corrosion could be caused, which inevitably led to a decrease in the mechanical properties. To further improve the performance of the deposited layer, a T6 heat treatment process was performed at 470 °C for 2 h, followed by rapid cooling with distilled water and artificial aging at 120 °C for 24 h. After heat treatment, many second phases appeared in the microstructure of the deposited layer, and the tensile strength increased from (361.8 ± 4.8) MPa to (510.2 ± 5.4) MPa together with the elongation which increased from (9.5 ± 0.5) % to (10.2 ± 0.4) %. The fracture mode of the fracture was a ductile fracture along grain boundaries. The microhardness increased from (145 ± 5) HV to (190 ± 4) HV and exhibited good corrosion resistance in a 3.5% NaCl solution corrosion test.

Effect of Heat Treatment Process on the Surface Integrity of 7A04 Aluminum Alloy

Effect of Heat Treatment Process on the Surface Integrity of 7A04 Aluminum Alloy

Characteristics of Silica Powder Extracted from Fly Ash of Coal Fired Power Plant: Effect of Heat Treatment Process

Characteristics of Silica Powder Extracted from Fly Ash of Coal Fired Power Plant: Effect of Heat Treatment Process

Effect of heat treatment process on microstructure and properties of depleted uranium No.2 alloy

By controlling the heat treatment temperature, the influence of aging process on the microstructure and mechanical properties of depleted uranium No.2 alloy was studied, and the dynamic properties of No.2 alloy were analyzed by Hobkinson device, and the stress-strain relationship was tested. The results show that, after solution treatment at 850 °C × 2h and aging treatment at 350 °C × 4h, the microstructure of No.2 alloy is mainly U(γ) phase and U (α /), and the dynamic yield strength of the alloy reaches the peak, which can reach 1580MPa, which is more than 40% higher than the quasi-static yield strength and has a strong strain rate hardening effect.

Effect of heat treatment regime on microstructure and phase evolution of AlMo0.5NbTa0.5TiZr refractory high entropy alloy

This paper reports the effect of heat treatment process on the ensuing microstructure evolution, and hardness variation of a cast and homogenized AlMo0.5NbTa0.5TiZr refractory high-entropy alloy (RHEA). Heat treatments were carried out on the homogenized samples at 1000, 1100, and 1200 °C for 10, 24, and 48 h. It was revealed that the phase decomposition in the alloy took place in a much shorter time than that reported in the literature. The significant tendency of Zr and Ti in respect of separation from the solid solution was found as the main reason for the formation of multi-phase structure and causing thermal instability. The phase decomposition occurred though the formation of Zr-rich needle-like phase constituents and Ti-rich globular ones. The semi-stable Zr-rich phase constituents are believed to form on B2 lamellas, and during their growth, the crystal structure gradually transforms from body-centered cubic (BCC) to a hexagonal close-packed (HCP) configuration. The electron back-scattered diffraction (EBSD) analyses confirmed that the HCP phase fraction increased significantly with increase in annealing temperature and/or time. A remarkable increase of 78% in Vickers hardness was measured for the sample heat treated at 1100 °C for 24 h compared to that of the homogenized state. It turned out that the morphology, size, interface coherency, and volume fraction of the needle-like precipitates played the leading role in influencing the alloy’s hardness. A comprehensive mechanism has been proposed for the phase decomposition of the alloy, based on the microstructure and chemical composition variations.

Modeling of wear resistance for TC21 Ti-alloy using response surface methodology

This study investigated the effect of heat treatment processes on the dry sliding wear resistance of the TC21 Ti-alloy at several levels of normal load and sliding speed. Response Surface Methodology (RSM) has been used as a design of the experiment procedure. OM and FESEM besides XRD analysis were used for results justification. Highest hardness of 49 HRC was recorded for WQ + Aging specimens due to the plenty of α″ which decomposed to αs and the more αs, while the lowest hardness of 36 HRC was reported for WQ specimens. The results revealed that specimens subjected to water quenching and aging (WQ + Aging) under extreme load and speed conditions (50 N and 3 m/s), possessed the poorest wear resistance although they had the highest hardness. While those left in the annealed condition revealed the highest wear resistance although they had much lower hardness when compared to other conditions. A mathematical polynomial model for wear resistance expressed in wear rate was developed, validated then used to get the optimum parameters.

Effect of Heat Treatment Processes on the Microstructure and Mechanical Properties of Spray‐Formed 440C Martensitic Stainless Steel

Herein, 440C martensitic stainless steel (440C MSS) is manufactured by spray forming (SF) technology. Microstructural and mechanical properties such as strength, ductility, and toughness are evaluated after quenching and tempering–partitioning (Q–TP) and quenching–intercritical–quenching–tempering (Q–IQ–T) heat treatments. The microstructural features that control the deformation and fracture behavior of the heat‐treated specimens are discussed. The experimental results show that after austenitizing at 1050 °C, the material exhibits no apparent plastic deformation before fracture. However, specimens austenitized above 1050 °C and the specimen subjected to Q–IQ–T exhibit an improvement in the tensile properties by showing an elastic–plastic transition that is related to the strain‐induced martensitic transformation of retained austenite formed during the Q–TP process and to a decrease in the volume fraction of martensite with increasing austenitizing temperature. Also, it is observed that the strain hardening rate decreases with increasing austenitizing temperature. Furthermore, the stress–strain data suggest that the Q–IQ–T heat treatment effectively improves the toughness and ductility of the steel without compromising strength. The results indicate that the mechanical response of the SF‐440C MSS can be tailored by adjusting the heat treatment parameters to enable better design for industrial applications.

A Novel Continuous Cooling Treatment Based on the Carbon Diffusion Process During Nanobainite Transformation in High‐Carbon Steel

A novel methodology of carbon‐diffusion‐dominated continuous cooling treatment (CC) during the bainite transformation is proposed and implemented on a high‐carbon nanobainitic steel. Nanobainite (NB) microstructure composed of bainitic ferrite lath with a thickness of ≈36 nm is obtained by successive heat treatment processes, including cooling the sample from 240 to 216 °C at a rate of 0.1 °C min−1, then cooling down to 120 °C at a rate of 0.2 °C min−1 followed by austempering at 120 °C for 12 h. Several technological routines involving oil quenching + tempering, single‐stage austempering + tempering, and two‐stage austempering + tempering are compared. The effects of heat treatment processes on the microstructure and mechanical properties are unveiled. Importantly, after the CC process, the tensile strength is 2049 MPa, the yield strength is 1552 MPa, the elongation is 2.5%, the impact toughness is 11.5 J, and the hardness is 60.7 HRC. Notably, the comprehensive mechanical properties of CC‐processed samples are superior to that of other heat‐treated samples. Microstructure analyses reveal that the CC process significantly refines the bainitic ferrite lath thickness while increasing the volume fraction of NB. Thereby, effectively shrink blocky retained austenite, and finally enhancing the overall mechanical properties.

Effect of Heat Treatment Process on the Optimization of Grain Boundary Character Distribution in Heavy Gage Austenitic Stainless Steel

The optimization of grain boundary character distribution (GBCD) is of great significance to improve the GB-related properties for heavy-gauge austenitic stainless steels worked in harsh environments such as reactors of nuclear power, which can usually be realized by regulating the thermomechanical process. In this paper, special solution annealing processes for a hot-rolled nuclear grade 316H plate were designed to introduce different character distribution of Σ3n boundaries (1 ≤ n ≤ 3) and random high-angle GBs (RHAGBs), and the regulation principle among them were clarified. It was worked out that the optimized GBCD by characterization of large twin related domains, abundant interconnected Σ3n boundaries and interrupted topology network of RHAGBs could be effectively facilitated through solution annealing with a long time period at lower temperature or short time period at higher temperature, in which the recrystallization, grain growth and GB migration during heat treatment process played key roles. Moreover, the length fraction of Σ3n boundaries were found to be hardly changed when they reached about 77%, but their character distribution could be continuously optimized.

Effect of heat treatment process on the micro machinability of 7075 aluminum alloy

This work aims to investigate the effect of heat treatment process on the micro machinability of 7075 aluminum alloy,7075 aluminum alloy was treated with T6, T73 and RRA.T6 single-stage aging process is 120 °C × 24 h; T73 two-stage aging process is 140 °C × 8 h + 180 × 12 h; retrogression and reaging (RRA) process is 120 °C × 16 h + 190 °C × 10min + 160 °C × 30 h. Finite element simulation and single-factor testing are used to examine how different heat treatment processes and different cutting parameters affect the cutting force, surface roughness, surface quality, and residual stress of 7075 aluminum alloy during micro machining.Under all three heat treatment processes, the cutting force of 7075 aluminum alloy increases with increasing cutting speed and cutting depth, but it is less affected by feed rate. Under the same cutting parameters, the cutting force of 7075 aluminum alloy under the three heat treatment processes is T73 > T6 > RRA. Under all three heat treatment processes, the surface roughness of 7075 aluminum alloy is negatively correlated with cutting speed and cutting depth, but positively correlated with feed rate. In the meantime, the micro-machined surface quality of 7075-RRA aluminum alloy is worse than that of 7075-T73 and 7075-T6 aluminum alloy. As cutting speed and cutting depth increase, the residual stress of 7075 aluminum alloy displays a typical “ladle” profile under all three heat treatment processes. When cutting speed changes, the machined surface residual tensile stress of 7075 aluminum alloy changes in much the same way under all three heat treatment processes. When cutting depth changes, the residual tensile stress of 7075 aluminum alloy under the three heat treatment processes is T73 > RRA > T6.