Tong Wang, Yang-xin Wang, Chun-dong Hu, Peng-min Cao, Han Dong
{"title":"Mechanical properties and microstructure evolution of 1800 MPa grade low alloy ultrahigh strength steel during quenching and tempering process","authors":"Tong Wang, Yang-xin Wang, Chun-dong Hu, Peng-min Cao, Han Dong","doi":"10.1007/s42243-024-01289-0","DOIUrl":"https://doi.org/10.1007/s42243-024-01289-0","url":null,"abstract":"<p>The characterization techniques were employed like transmission electron microscope, X-ray diffraction and microstructural characterization to investigate microstructural evolution and impact of precipitate-phase precipitation on strength and toughness of a self-developed 32Si<sub>2</sub>CrNi<sub>2</sub>MoVNb steel during the quenching and tempering process. Research outputs indicated that the steel microstructure under the quenching state could be composed of martensite with a high dislocation density, a small amount of residual austenite, and many dispersed spherical MC carbides. In details, after tempering at 200 °C, fine needle-shaped ε-carbides would precipitate, which may improve yield strength and toughness of the steel. However, as compared to that after tempering at 200 °C, the average length of needle-shaped ε-carbides was found to increase to 144.1 ± 4 from 134.1 ± 3 nm after tempering at 340 °C. As a result, the yield strength may increase to 1505 ± 40 MPa, and the impact absorption energy (V-notch) may also decrease. Moreover, after tempering at 450 °C, those ε-carbides in the steel may transform into coarse rod-shaped cementite, and dislocation recoveries at such high tempering temperature may lead to decrease of strength and toughness of the steel. Finally, the following properties could be obtained: a yield strength of 1440 ± 35 MPa, an ultimate tensile strength of 1864 ± 50 MPa and an impact absorption energy of 45.9 ± 4 J, by means of rational composition design and microstructural control.</p>","PeriodicalId":16151,"journal":{"name":"Journal of Iron and Steel Research International","volume":"40 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141944353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Microstructure evolution and mechanical properties improvement of (Ti8Zr6Nb4V5Cr4)100−xAlx lightweight high-entropy alloy by Laves phase transformation","authors":"Qin Xu, Cheng-yuan Guo, Qi Wang, Peng-yu Sun, Ya-jun Yin, Rui-run Chen","doi":"10.1007/s42243-024-01280-9","DOIUrl":"https://doi.org/10.1007/s42243-024-01280-9","url":null,"abstract":"<p>(Ti<sub>8</sub>Zr<sub>6</sub>Nb<sub>4</sub>V<sub>5</sub>Cr<sub>4</sub>)<sub>100−<i>x</i></sub>Al<sub><i>x</i></sub> (<i>x</i> = 0, 0.1, 0.2, 0.3, 0.4 at.%) lightweight high-entropy alloys with different contents of Al were prepared via vacuum non-consumable arc melting method. Effects of adding varying Al contents on phase constitution, microstructure characteristics and mechanical properties of the lightweight alloys were studied. Results show that Ti<sub>8</sub>Zr<sub>6</sub>Nb<sub>4</sub>V<sub>5</sub>Cr<sub>4</sub> alloy is composed of body-centered cubic (BCC) phase and C15 Laves phase, while (Ti<sub>8</sub>Zr<sub>6</sub>Nb<sub>4</sub>V<sub>5</sub>Cr<sub>4</sub>)<sub>100−<i>x</i></sub>Al<sub><i>x</i></sub> lightweight high-entropy alloys by addition of Al are composed of BCC phase and C14 Laves phase. Addition of Al into Ti<sub>8</sub>Zr<sub>6</sub>Nb<sub>4</sub>V<sub>5</sub>Cr<sub>4</sub> lightweight high-entropy alloy can transform C15 Laves phase to C14 Laves phase. With further addition of Al, BCC phase of alloys is significantly refined, and the volume fraction of C14 Laves phase is raised obviously. Meanwhile, the dimension of BCC phase in the alloy by addition of 0.3 at.% Al is the most refined and that of Laves phase is also obviously refined. Adding Al to Ti<sub>8</sub>Zr<sub>6</sub>Nb<sub>4</sub>V<sub>5</sub>Cr<sub>4</sub> alloy can not only reduce the density of (Ti<sub>8</sub>Zr<sub>6</sub>Nb<sub>4</sub>V<sub>5</sub>Cr<sub>4</sub>)<sub>100−<i>x</i></sub>Al<sub><i>x</i></sub> alloy, but also improve strength of (Ti<sub>8</sub>Zr<sub>6</sub>Nb<sub>4</sub>V<sub>5</sub>Cr<sub>4</sub>)<sub>100−<i>x</i></sub>Al<sub><i>x</i></sub> alloy. As Al content increased from 0 to 0.4 at.%, the density of the alloy decreased from 6.22 ± 0.875 to 5.79 ± 0.679 g cm<sup>−3</sup>. Moreover, compressive strength of the alloy by 0.3 at.% Al addition is the highest to 1996.9 MPa, while fracture strain of the alloy is 16.82%. Strength improvement of alloys mainly results from microstructure refinement and precipitation of C14 Laves by Al addition into Ti<sub>8</sub>Zr<sub>6</sub>Nb<sub>4</sub>V<sub>5</sub>Cr<sub>4</sub> lightweight high-entropy alloy.</p>","PeriodicalId":16151,"journal":{"name":"Journal of Iron and Steel Research International","volume":"7 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141944355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Reaction intermediates and products characterisation of NH3 in desulphurisation with activated coke","authors":"Wei-li Zhang, Meng Wang, Wen-zhe Si, Jun-hua Li","doi":"10.1007/s42243-024-01241-2","DOIUrl":"https://doi.org/10.1007/s42243-024-01241-2","url":null,"abstract":"<p>The sulphate is an important factor restricting the efficient and stable operation of the activated coke (AC) flue gas purification system. The simulation experiments and in situ infrared tests of AC taken from desorption tower of the AC flue gas purification system were carried out to first calibrate the thermal desorption characteristics of adsorbed NH<sub>3</sub> and sulphate and explore the reaction behaviour of NH<sub>3</sub> with SO<sub>2</sub> and H<sub>2</sub>SO<sub>4</sub>. On this basis, some advice for optimising the sulphate generation was put forward to improve the purification efficiency of the AC system. The results show that the temperatures of the desorption of adsorbed NH<sub>3</sub>, the decomposition of (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> and NH<sub>4</sub>HSO<sub>4</sub> are 224, 276 and 319 °C, respectively, which lays the foundation for the quantitative analysis of sulphate on AC. Regardless of the NH<sub>3</sub> amount, only a small portion of H<sub>2</sub>SO<sub>4</sub> is converted to sulphate, as the H<sub>2</sub>SO<sub>4</sub> deposited in AC pores or agglomerated together could not come into contact with NH<sub>3</sub>. The final reaction product of NH<sub>3</sub> and SO<sub>2</sub> is mainly (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> which is continuously generated because the newly generated H<sub>2</sub>SO<sub>4</sub> is continually exposed to NH<sub>3</sub>, if NH<sub>3</sub> is enough. The reaction of NH<sub>3</sub> with H<sub>2</sub>SO<sub>4</sub> takes precedence over with NH<sub>4</sub>HSO<sub>4</sub>. In the initial stages in which H<sub>2</sub>SO<sub>4</sub> is exposed to NH<sub>3</sub>, the product is essentially all NH<sub>4</sub>HSO<sub>4</sub> as intermediate. Then, it is further converted to (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> whose amount reaches equilibrium when the accessible H<sub>2</sub>SO<sub>4</sub> is exhausted. All the NH<sub>3</sub> adsorbed on AC entering the desulphurisation tower generates NH<sub>4</sub>HSO<sub>4</sub>, but the amount is limited. The remaining SO<sub>2</sub> entering the denitrification tower mainly generates (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>; thus, limiting the remaining SO<sub>2</sub> amount is necessary to guarantee denitrification efficiency. When the NH<sub>3</sub> injection is changed to the desulphurisation tower, the initial NH<sub>3</sub> injection rate can be increased to complete the conversion of accessible H<sub>2</sub>SO<sub>4</sub> as soon as possible in order to obtain higher denitrification efficiency.</p>","PeriodicalId":16151,"journal":{"name":"Journal of Iron and Steel Research International","volume":"198 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141944356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xue-yun Gao, Wen-bo Fan, Lei Xing, Hui-jie Tan, Xiao-ming Yuan, Hai-yan Wang
{"title":"Construction of a prediction model for properties of wear-resistant steel using industrial data based on machine learning approach","authors":"Xue-yun Gao, Wen-bo Fan, Lei Xing, Hui-jie Tan, Xiao-ming Yuan, Hai-yan Wang","doi":"10.1007/s42243-024-01279-2","DOIUrl":"https://doi.org/10.1007/s42243-024-01279-2","url":null,"abstract":"<p>A prediction model leveraging machine learning was developed to forecast the tensile strength of wear-resistant steels, focusing on the relationship between composition, hot rolling process parameters and resulting properties. Multiple machine learning algorithms were compared, with the deep neural network (DNN) model outperforming others including random forests, gradient boosting regression, support vector regression, extreme gradient boosting, ridge regression, multi-layer perceptron, linear regression and decision tree. The DNN model was meticulously optimized, achieving a training set mean squared error (MSE) of 14.177 with a coefficient of determination (<i>R</i><sup>2</sup>) of 0.973 and a test set MSE of 21.573 with an <i>R</i><sup>2</sup> of 0.960, reflecting its strong predictive capabilities and generalization to unseen data. In order to further confirm the predictive ability of the model, an experimental validation was carried out, involving the preparation of five different steel samples. The tensile strength of each sample was predicted and then compared to actual measurements, with the error of the results consistently below 5%.</p>","PeriodicalId":16151,"journal":{"name":"Journal of Iron and Steel Research International","volume":"15 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141969350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chao-qun Xia, Hong-pu Zhou, Tian-shuo Song, Shu-guang Liu, Tai Yang, Qiang Li
{"title":"Effect of hot rolling treatment on microstructure, mechanical, and corrosion properties of Zr–Sn–Co ternary alloys","authors":"Chao-qun Xia, Hong-pu Zhou, Tian-shuo Song, Shu-guang Liu, Tai Yang, Qiang Li","doi":"10.1007/s42243-024-01287-2","DOIUrl":"https://doi.org/10.1007/s42243-024-01287-2","url":null,"abstract":"<p>The microstructure, mechanical properties, and corrosion resistance of as-cast Zr–Sn–Co ternary alloys have been investigated in this experiment. The properties of as-cast Zr–1.5Sn–<i>x</i>Co (<i>x</i> = 0, 2.5, 5, 7.5, and 10 at.%) ternary alloys were investigated, and the alloy composition exhibiting the best comprehensive performance was identified. Subsequently, the chosen alloys were subjected to hot rolling treatment. The microstructure of the alloys in the rolled state was analyzed using the optical microscope, X-ray diffractometer, and scanning electron microscope. The mechanical properties of the alloys were analyzed using room temperature compression tests and microhardness tests, while the corrosion properties of the alloy were investigated through electrochemical testing. The results show that the strength of as-cast Zr–1.5Sn–Co ternary alloy increases significantly with the increase in Co content. The incorporation of Co element makes the corrosion resistance of as-cast Zr–1.5Sn–Co alloy increase significantly. The hot rolling treatment has minimal effect on enhancing the corrosion resistance of Zr–1.5Sn–2.5Co alloy. However, the mechanical properties of Zr–1.5Sn–2.5Co alloy after rolling treatment are significantly enhanced. The alloy exhibits the highest strength and hardness at a rolling temperature of 600 °C and exhibits the best plasticity at a rolling temperature of 800 °C.</p>","PeriodicalId":16151,"journal":{"name":"Journal of Iron and Steel Research International","volume":"26 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141881689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ming-yue Yang, Sheng-wei Wang, Shui-ze Wang, Yu-he Huang, Xin-ping Mao
{"title":"Effect of compact strip processing on segregation behavior and mechanical properties of Q&P steel","authors":"Ming-yue Yang, Sheng-wei Wang, Shui-ze Wang, Yu-he Huang, Xin-ping Mao","doi":"10.1007/s42243-024-01259-6","DOIUrl":"https://doi.org/10.1007/s42243-024-01259-6","url":null,"abstract":"<p>The microstructure and mechanical properties of the compact strip production (CSP) processed quenching and partitioning (Q&P) steels were investigated through experimental methods to address the challenge of designing high-performance Q&P steels. Compared with the conventional process (CP) produced samples, with slightly reduced strength, the total elongation of the CSP produced samples was increased by nearly 7%. Microstructural analysis revealed that variations in austenite stability were not the primary cause for the differences in mechanical properties between the CSP and the CP. The CSP processed Q&P steel exhibited milder center segregation behavior in contrast to the CP processed Q&P steel. Consequently, in the CSP processed Q&P steel, a higher proportion of austenite and a lower proportion of martensite were observed at the center position, delaying the crack initiation in the central region and contributing to the enhanced ductility. The investigation into the CSP process reveals its effect on alleviation of segregation and enhancement of mechanical properties of the Q&P steel.</p>","PeriodicalId":16151,"journal":{"name":"Journal of Iron and Steel Research International","volume":"77 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141869751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ming-shuai Huo, Hai-bo Xie, Tao Zhang, Guan-qiao Su, Lian-jie Li, Meng-yuan Ren, Zhou Li, Jing-bao Liu, Ting Yang, Xi Zhang, Yan-bin Du, Valerie Linton, Zheng-yi Jiang
{"title":"Multiscale analysis of microstructure-based bending characteristics of advanced high strength dual-phase steel","authors":"Ming-shuai Huo, Hai-bo Xie, Tao Zhang, Guan-qiao Su, Lian-jie Li, Meng-yuan Ren, Zhou Li, Jing-bao Liu, Ting Yang, Xi Zhang, Yan-bin Du, Valerie Linton, Zheng-yi Jiang","doi":"10.1007/s42243-024-01264-9","DOIUrl":"https://doi.org/10.1007/s42243-024-01264-9","url":null,"abstract":"<p>Different stress states have a significant influence on the magnitude of the microscopic plastic strain and result in the development of the microstructure evolution. As a result, a comprehensive understanding of the different scale variation on microstructure evolution during bending deformation is essential. The advanced high strength dual-phase (DP1180) steel was investigated using multiscale microstructure-based 3D representative volume element (RVE) modelling technology with emphasis on understanding the relationship between the microstructure, localised stress–strain evolution as well as the deformation characteristics in the bending process. It is demonstrated that the localised development in bending can be more accurately described by microscopic deformation when taking into account microstructural properties. Microstructure-based 3D RVEs from each chosen bending condition generally have comparable localisation properties, whilst the magnitudes and intensities differ. In addition, the most severe localised bands are predicted to occur close to the ferrite and martensite phase boundaries where the martensite grains are close together or have a somewhat sharp edge. The numerically predicted results for the microstructure evolution, shear bands development and stress and strain distribution after 3-point bending exhibit a good agreement with the relevant experimental observations.</p>","PeriodicalId":16151,"journal":{"name":"Journal of Iron and Steel Research International","volume":"21 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141873173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Flow and fluctuation of molten steel under permanent magnet flow control-mold in continuous casting process","authors":"Ze-feng Han, En-gang Wang, Ze-peng Wang, Zhong-xin Zhai","doi":"10.1007/s42243-024-01275-6","DOIUrl":"https://doi.org/10.1007/s42243-024-01275-6","url":null,"abstract":"<p>A new flow control technology in continuous casting process named permanent magnet flow control-mold (PMFC-Mold) was proposed, in which the permanent magnets are arranged in Halbach array near the narrow region of the mold. The behavior of molten steel flow and the fluctuation of molten steel/slag interface in the PMFC-Mold under different continuous casting speeds were investigated. Firstly, a physical experiment of liquid Ga–In–Sn alloy circulating flow was carried out in Perspex mold with Halbach’s permanent magnets (HPMs) to investigate the magnetic field distribution of HPMs and its impactful electromagnetic braking effect. The numerical simulation of 1450 mm × 230 mm slab shows that a stronger magnetic field over 0.3–0.625 T is formed at the wide surface and the narrow surface of the mold, which provides an effective electromagnetic braking for controlling the impingement of molten steel jet and suppressing the fluctuation of molten steel/slag interface. The numerical simulation results show that in the PMFC-Mold, the region with the turbulent kinetic energy greater than 0.01 and 0.04 m<sup>2</sup> s<sup>−2</sup> on the upper backflow zone and near the narrow surface of the mold are significantly reduced. The maximum turbulent kinetic energy of the submerged entry nozzle (SEN) jet in front of the narrow surface is significantly reduced, and the SEN jet moves downward before impacting the narrow surface of the mold. In the PMFC-Mold, the region with the surface velocity greater than 0.2 m s<sup>−1</sup> on the steel/slag interface is eliminated, the flow pattern and fluctuation profiles on the molten steel/slag interface become regular on both sides of SEN, and the vortex near SEN disappears. The maximum fluctuation height of molten steel/slag interface is controlled below 2.59 and 5.40 mm corresponding to the casting speed of 1.6 and 2.0 m min<sup>−1</sup>, respectively.</p>","PeriodicalId":16151,"journal":{"name":"Journal of Iron and Steel Research International","volume":"88 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141869933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effects of different annealing temperatures on microstructure, mechanical properties, and magnetic properties of cold-rolled 20Mn23AlV non-magnetic structural steel","authors":"Xing-chang Tang, Gang-hu Cheng, Zhi-hui Jia, Da-yang Qi, Zhi-jian Zhang, Ying-ying Shen, Wei-lian Zhou, Yuan-yuan Hou","doi":"10.1007/s42243-024-01278-3","DOIUrl":"https://doi.org/10.1007/s42243-024-01278-3","url":null,"abstract":"<p>The variations in the mechanical and magnetic properties of cold-rolled 20Mn23AlV non-magnetic structural steel after annealing at different temperatures were investigated. The microstructure and precipitation changes during annealing were studied by optical microscopy, scanning electron microscopy, and transmission electron microscopy. The results show that recrystallization completed after annealing at 620 °C, resulting in grain sizes of approximately 800 nm and the best combination of strength and plasticity. The yield-to-tensile ratio of the non-magnetic structural steel after cold rolling continuously decreases from low to high temperatures after annealing, with the highest value being 0.89 and the lowest value being 0.43, indicating a wide range of yield-to-tensile ratio adjustment. The introduction of numerous dislocations during cold rolling provided favorable nucleation sites for precipitation, leading to abundant precipitation of the fine second-phase V(C, N). The phase composition of the samples remained unchanged as single-phase austenite after annealing, and the relative permeability values were calculated to be less than 1.002, meeting the requirements for non-magnetic steel in terms of magnetic properties.</p>","PeriodicalId":16151,"journal":{"name":"Journal of Iron and Steel Research International","volume":"11 3 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141873172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jing Zhang, Wen-bin Xin, Deng-yun Hou, Jun Peng, Zhi-bo Zhao, Yang Tong
{"title":"Effect of Mo on acicular ferrite transformation and interphase precipitation of Nb–V–N microalloyed steel during a continuous cooling process","authors":"Jing Zhang, Wen-bin Xin, Deng-yun Hou, Jun Peng, Zhi-bo Zhao, Yang Tong","doi":"10.1007/s42243-024-01281-8","DOIUrl":"https://doi.org/10.1007/s42243-024-01281-8","url":null,"abstract":"<p>The substantial influences of Mo contents varying from 0 to 0.26 and 0.50 wt.% on the microstructural evolution and MX (M = Nb, V and Mo; X = C and N) precipitation characteristics of Nb–V–N microalloyed steels processed by hot deformation and continuous cooling were studied using a Gleeble 3800 thermomechanical simulator. Metallographic analysis showed that the ferrite microstructure transformed from polygonal ferrite (PF) in 0Mo steel to both acicular ferrite (AF) and PF in 0.26Mo and 0.50Mo steels, and AF content first increased and then decreased. The thermodynamic calculations and the experimental results proved that the quantity of solid solution of Mo in austenite obviously increased, which reduced the austenite (γ) to ferrite (α) transformation temperature, consequently promoting AF formation in 0.26Mo steel and bainite transformation in 0.50Mo steel. Moreover, the submicron Nb-rich MX particles that precipitated at the temperature of the austenite region further induced AF heterogeneous nucleation with an orientation relationship of <span>((011)_{{{text{MX}}}} //(100)_{{{text{Ferrite}}}})</span> and <span>([1overline{1}1]_{{{text{MX}}}} //[001]_{{{text{Ferrite}}}})</span>. The interphase precipitation of the nanosized V-rich MX particles with Mo partitioning that precipitated during γ → α transformation exhibited a Baker–Nutting orientation relationship of <span>(left( {100} right)_{{{text{MX}}}} //left( {100} right)_{{{text{Ferrite}}}})</span> and <span>(left[ {001} right]_{{{text{MX}}}} //left[ {01overline{1}} right]_{{{text{Ferrite}}}})</span> with respect to the ferrite matrix. With increasing Mo content from 0 to 0.26 and 0.50 wt.%, the sheet spacing decreased from 46.9–49.0 to 34.6–38.6 and 25.7–28.0 nm, respectively, which evidently hindered dislocation movement and greatly enhanced precipitation strengthening. Furthermore, facilitating AF formation and interphase precipitation was beneficial to improving steel properties, and the optimal Mo content was 0.26 wt.%.</p>","PeriodicalId":16151,"journal":{"name":"Journal of Iron and Steel Research International","volume":"10 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141869752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}