Materials Characterization最新文献

{"title":"Effects of ZrC addition on the recrystallization behavior of ZrC-dispersion strengthened FeCrAl alloys","authors":"Gangming Chen ,&nbsp;Yongduo Sun ,&nbsp;Hui Wang ,&nbsp;Xuefei Huang","doi":"10.1016/j.matchar.2024.114547","DOIUrl":"10.1016/j.matchar.2024.114547","url":null,"abstract":"<div><div>ZrC-dispersion strengthened FeCrAl (ZrC-FeCrAl) alloy is one of the promising cladding materials for advanced nuclear reactors. The thermal stability of ZrC-FeCrAl alloy is closely associated with its recrystallization behavior. In this study, the effects of different ZrC contents (0–1.5 wt%) on the recrystallization behavior of FeCrAl alloys were investigated. It was found that ZrC addition impedes the recovery and recrystallization processes, with higher ZrC content resulting in higher recrystallization temperatures. Specifically, the addition of 1.5 wt% ZrC increased the recrystallization finishing temperature from 700 °C to 1000 °C. ZrC delays the initiation and completion of recrystallization as well as the onset and termination of grain growth, with higher ZrC content leading to more pronounced delaying effects and extended incubation periods for recrystallization. Furthermore, ZrC influences recovery and recrystallization by affecting the precipitation of M₂₃C₆ and Al₂O₃. ZrC addition also significantly enhances both room-temperature (RT) and high-temperature strength of the alloys. While low ZrC content markedly improves ductility, excessive ZrC content can impair it. The FeCrAl alloy with 0.5 wt% ZrC exhibited the best comprehensive mechanical properties. Moreover, with increasing ZrC content, the fracture mode of the alloy shifts from ductile to brittle fracture.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114547"},"PeriodicalIF":4.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656753","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":"Evolution of microstructures in laser additive manufactured HT-9 ferritic martensitic steel","authors":"Madhavan Radhakrishnan ,&nbsp;Shashank Sharma ,&nbsp;Selvamurugan Palaniappan ,&nbsp;Narendra B. Dahotre","doi":"10.1016/j.matchar.2024.114551","DOIUrl":"10.1016/j.matchar.2024.114551","url":null,"abstract":"<div><div>A comparative study to understand the influence of processing conditions on the microstructural and phase evolution in HT9 ferritic/martensitic (F/M) steels, fabricated using laser powder bed fusion and laser directed energy deposition methods, was undertaken. The microstructural and phase evolutions during the laser-based additive manufacturing processes were compared with the HT9 steel fabricated using conventional vacuum arc melting and explained through the thermokinetic conditions associated with these manufacturing processes. Electron back scattered diffraction microstructures of the cross-sections reveal that the L-PBF processed HT9 steel microstructures comprised δ-ferrite, martensite (α’) and retained austenite (γ), whereas the L-DED microstructure consisted of α’ and retained γ, and no evidence of retained δ-ferrite was found. The arc melted steel showed predominantly martensite and a small amount of retained δ-ferrite. The L-PBF and L-DED microstructures comprise 15–21 % and 3–5 % of retained γ along the build direction, respectively. A multiscale multiphysics thermal model approach was adopted to deduce the correlation between the experimentally observed phase fractions and process-induced thermo-kinetics. The nanoindentation based hardness and yield stress obtained through spherical indentation technique, correlates well with the fraction of retained austenite. The experimental findings coupled with modelling aspects offer valuable insights into the intricate interplay between processing routes, phase evolution, and mechanical attributes in HT9 steel.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114551"},"PeriodicalIF":4.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656751","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":"Enhanced mechanical properties of lightweight refractory high-entropy alloys at elevated temperatures via Si addition","authors":"Tiantian Wang ,&nbsp;Wentao Jiang ,&nbsp;Xiaohong Wang ,&nbsp;Bo Jiang ,&nbsp;Ye Wang ,&nbsp;Xin Wang ,&nbsp;Hongyu Xu ,&nbsp;Maoliang Hu ,&nbsp;Dongdong Zhu","doi":"10.1016/j.matchar.2024.114552","DOIUrl":"10.1016/j.matchar.2024.114552","url":null,"abstract":"<div><div>A new lightweight refractory high-entropy alloys were prepared by introducing Si element into AlMo_0.5NbTiV alloy. The effects of Si content on microstructural evolution, density and high temperature mechanical properties were analyzed. The results show that the addition of Si leads to the formation of hard and brittle M₅Si₃-type (M = Ti and Nb) phase at the grain boundary of the matrix, which gradually transforms the alloys from a single body centered cubic (BCC) structure to a dual-phase structure. While the density of AlMo_0.5NbTiVSi_x alloys decreases from 6.01 to 5.59 g/cm³ with the increase of Si content, and the mechanical properties are also significantly improved, AlMo_0.5NbTiVSi_0.5 alloy has the best yield strength of 1428 and 390 MPa at 1073 K and 1273 K, respectively. Among them, AlMo_0.5NbTiVSi_0.1 alloy has the best compression ductility strain at 1073 K, up to 22.2 %, indicating that the addition of appropriate Si can improve the compression ductility of the alloy, which is also caused by the combination of grain refinement and the appearance of eutectic structure. On the one hand, the segregation of Si elements at grain boundaries results in slow growth of the primary crystal, which inhibits the growth of grains. On the other hand, the eutectic structure composed of M₅Si₃ and BCC is distributed at the grain boundary, which is not conducive to the growth of grains, and the combined effect of the two eventually leads to the grain refinement. The strengthening mechanisms of the alloys can be attributed to the second phase strengthening, solid solution strengthening and grain refinement strengthening. In addition, the softening of the alloys at 1273 K is caused by dynamic recovery and dynamic recrystallization, and the dynamic recovery is the main softening mechanism.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114552"},"PeriodicalIF":4.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656752","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":"Comprehensive analysis of beryllium content influence on secondary electron yield in CuBe alloys","authors":"Can Wang ,&nbsp;Daibo Zhu ,&nbsp;Wenming Zhu ,&nbsp;Hailin Liu ,&nbsp;Xinyan Liu ,&nbsp;Xiaoyu Jiang ,&nbsp;Fan Zhou ,&nbsp;Yanbin Jiang ,&nbsp;Xiaochen Ding ,&nbsp;Tao Deng","doi":"10.1016/j.matchar.2024.114553","DOIUrl":"10.1016/j.matchar.2024.114553","url":null,"abstract":"<div><div>This study examines the impact of varying Be contents on the evolution of secondary electron emission (SEE) properties. Through microscopic characterization of the microstructure before and after activation, it was determined that the phase composition was <em>α</em>(Cu) phase and eutectic structure (<em>α</em>(Cu) + <em>γ</em>). The findings indicate that as the Be content increased from 2.8 wt.% to 3.8 wt.%, the proportion of heterogeneous structures increased and the distribution became more uniform. Meanwhile, the number of heterogeneous structure interfaces between <em>α</em>(Cu) phase and <em>γ</em> phase increased, and there were a large number of mismatch dislocations at the interfaces, which served as short-circuit diffusion paths for Be elements. Be elements were more easily able to diffuse outward through the interface to form a uniform BeO film, thereby increasing secondary electron yield (SEY). In addition, the density of mismatch dislocations near the interface was high, promoting the formation of grain boundaries, which provided more diffusion pathways, allowing Be elements to diffuse outward more easily, thereby generating a uniform BeO film with increased SEY. This study holds significant implications for augmenting the SEY of Cu<img>Be dynode electrodes used in photomultiplier tubes (PMTs).</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114553"},"PeriodicalIF":4.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656336","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":"Effect of grain size on precipitation and microstrain of nanocrystalline NiTi alloys","authors":"Penghui Li ,&nbsp;Wang Tang ,&nbsp;Qihang Shen ,&nbsp;Xiaobin Shi ,&nbsp;Ping Liu","doi":"10.1016/j.matchar.2024.114549","DOIUrl":"10.1016/j.matchar.2024.114549","url":null,"abstract":"<div><div>The effect of aging treatment on the microstructure, phase transformation behavior and mechanical properties of nanocrystalline NiTi alloy was studied. The nanocrystalline NiTi alloys with different grain sizes were acquired by cold drawing followed by annealing at 350–500 °C for 10 min. The annealed samples were aged at 250–400 °C for 48 h. The Ti₃Ni₄ precipitates were found in aged nanocrystalline NiTi alloys. In the sample with smaller average nanograin size, the precipitates were found at the edge of grain boundaries and little lattice strain was shown in R phase matrix. In the sample with larger average grain size, the precipitates were found in the nanograins and exhibited a coherent interface with the matrix. The nanocrystalline R phase NiTi matrix exhibited a significant compressive stress at the end of the coherent precipitate. The coherent precipitates in sample aged at 250 °C after annealing at 500 °C suppress the stress-induced R → B19′ phase transformation and increased the upper plateau stress. The precipitation in sample aged at 250 °C after annealing at 350 °C unable to suppress the martensitic transformation effectively.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114549"},"PeriodicalIF":4.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656755","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":"Direct observation of the evolution behavior of micro to nanoscale precipitates in austenitic heat-resistant steel via electron channeling contrast imaging","authors":"Hongyu Zhou ,&nbsp;Yuchen Zhao ,&nbsp;Zhangjian Zhou ,&nbsp;Wenyue Zheng ,&nbsp;Yinsheng He","doi":"10.1016/j.matchar.2024.114550","DOIUrl":"10.1016/j.matchar.2024.114550","url":null,"abstract":"<div><div>Precipitation directly determines the high-temperature properties of the austenitic heat-resistant steels. The precipitations of MX, <em>Z</em>-phase, M₂₃C₆ and σ-phase, ranging from micrometers to nanometers, are commonly characterized using the scanning electron microscopy (SEM) and transmission electron microscopy (TEM). However, details of their evolution behavior are still unclear due to the limited SEM resolution using the traditional sampling method and the limited spatial resolution of TEM. In this work, field emission SEM-based electron channel contrast imaging (ECCI) techniques with flexible sampling routes were introduced to observe the precipitation evolution behavior of HR3C steel after aging at 700 °C for 8095 h. We showed that the coarse primary-MX and <em>Z</em>-phase in the as-received steel are relatively stable during aging. The coarse M₂₃C₆ and tiny secondary Z-phase dispersions were rapidly formed along the grain/twin boundaries and within dislocation arrays inside the grain interior, respectively. We further found that the M₂₃C₆ at grain boundaries would change from continuous to semi-continuous due to the formation of σ-phases, while in twin boundaries, it would become continuous over aging. Moreover, we showed that the σ-phases were in-situ transformed from M₂₃C₆ at the grain boundaries via its dissolution, facilitating the nucleation of tiny <em>Z</em>-phase inside the σ-phase grains, and this phenomenon has not been reported so far. We have demonstrated that ECCI with an electrolytic-polishing-based sampling route is effective in revealing multi-scale precipitation with high-throughput efficiency, and it allows the direct observation of the complex behavior of precipitates down to the nanoscale using a bulk sample. This method can be used as an efficient way for the quantitative microstructure study.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114550"},"PeriodicalIF":4.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656687","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":"Theoretical precipitation modeling and multidimensional characterization of sulfide inclusions in tellurium-containing steels","authors":"Jin Wang ,&nbsp;Yun Bai ,&nbsp;Feilong Zhang ,&nbsp;Zexin Qi ,&nbsp;Wei Liu ,&nbsp;Qiang Liu ,&nbsp;Shufeng Yang ,&nbsp;Jingshe Li","doi":"10.1016/j.matchar.2024.114546","DOIUrl":"10.1016/j.matchar.2024.114546","url":null,"abstract":"<div><div>This study investigates the precipitation characteristics of sulfide inclusions during the solidification of alloy steels under the combined influence of sulfur (S), manganese (Mn), and tellurium (Te). A multidimensional characterization and comparison of sulfide inclusions in Te-containing steels with varying S content and cooling conditions were performed using X-ray Micro-CT, Raman spectroscopy, and field emission scanning electron microscopy (FE-SEM). Both 2D and 3D analyses confirmed that increasing the S content in Te-containing steels leads to a higher overall number of sulfide inclusions. In particular, the rise in the proportion of small-sized inclusions was analyzed from the perspectives of interfacial dynamics and equilibrium thermodynamics. Regarding inclusion morphology, 2D characterization exhibited significant inaccuracies in assessing large inclusions in high-S, Te-containing steels, while X-ray Micro-CT proved advantageous for evaluating both the spatial distribution and morphology of inclusions. In addition, X-ray Micro-CT was used for the first time in this study to perform a non-destructive analysis of the layered MnS-MnTe structure, expanding the method's application in the metallurgical field. A predictive model based on inter-element activity interaction coefficients was employed to determine the first-order activity interaction coefficient of Te for Mn. Furthermore, a thermodynamic model for sulfide precipitation in Te-containing steels was developed. This study lays a theoretical foundation for better control of sulfide inclusions in future Te-containing specialty steels.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114546"},"PeriodicalIF":4.8,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656754","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":"Achieving ultrahigh strength and ductility in biodegradable Zn-xCu alloys via hot-rolling and tailoring Cu concentration","authors":"Ya Yang ,&nbsp;Fei Zhao ,&nbsp;Dongbing Cui ,&nbsp;Yuanbiao Tan","doi":"10.1016/j.matchar.2024.114530","DOIUrl":"10.1016/j.matchar.2024.114530","url":null,"abstract":"<div><div>In this present paper, a biodegradable Zn-<em>x</em>Cu alloys with an ultrahigh strength and ductility can be achieved via hot-rolling and tailoring Cu concentration, and the role of Cu concentration on the microstructure and texture evolution in the Zn-<em>x</em>Cu alloys during hot-rolling were investigated by XRD, EBSD and TEM analysis. The results show that the microstructure of as-cast Zn-<em>x</em>Cu alloys consisted of large sized CuZn₅ phase and Zn matrix grains before hot-rolling, and numerous submicron CuZn₅ phase can dynamically precipitate during hot-rolling of Zn-<em>x</em>Cu alloys. The existence of CuZn₅ phase can result in the particle stimulated nucleation of recrystallization (PSN), and then result in the formation of fine recrystallized grains. Moreover, three texture components including <span><math><mfenced><mn>0001</mn></mfenced><mo>&lt;</mo><mn>11</mn><mover><mn>2</mn><mo>¯</mo></mover><mn>0</mn><mo>&gt;</mo></math></span>, <span><math><mfenced><mrow><mn>10</mn><mover><mn>1</mn><mo>¯</mo></mover><mn>1</mn></mrow></mfenced><mo>&lt;</mo><mover><mn>1</mn><mo>¯</mo></mover><mn>012</mn><mo>&gt;</mo></math></span> and <span><math><mfenced><mrow><mn>11</mn><mover><mn>2</mn><mo>¯</mo></mover><mn>0</mn></mrow></mfenced><mo>&lt;</mo><mn>0001</mn><mo>&gt;</mo></math></span> textures can form in the Zn-<em>x</em>Cu alloys after hot-rolling. With boosting Cu concentration, the intensity of <span><math><mfenced><mrow><mn>11</mn><mover><mn>2</mn><mo>¯</mo></mover><mn>0</mn></mrow></mfenced><mo>&lt;</mo><mn>0001</mn><mo>&gt;</mo></math></span> texture gradually reduced, while the intensity of <span><math><mfenced><mn>0001</mn></mfenced><mo>&lt;</mo><mn>11</mn><mover><mn>2</mn><mo>¯</mo></mover><mn>0</mn><mo>&gt;</mo></math></span> and <span><math><mfenced><mrow><mn>10</mn><mover><mn>1</mn><mo>¯</mo></mover><mn>1</mn></mrow></mfenced><mo>&lt;</mo><mover><mn>1</mn><mo>¯</mo></mover><mn>012</mn><mo>&gt;</mo></math></span> texture components firstly raised with the augment of Cu concentration, and then reduced. For the Zn-<em>x</em>Cu alloys with 8 wt%Cu concentration, a combination of high yield strength, ultimate tensile strength and elongation (269.7 MPa, 322.9 MPa and 26.3 %) can be achieved, which can meet the high-performance demands of biodegradable metal vascular stents.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114530"},"PeriodicalIF":4.8,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656809","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":"Surface mechanical property and residual stress stability of nanostructured CNT/Al-Cu-Mg composites induced by shot peening","authors":"Wenlong Zhu ,&nbsp;Huabing Liu ,&nbsp;Shilong Xing ,&nbsp;Chuanhai Jiang ,&nbsp;Vincent Ji","doi":"10.1016/j.matchar.2024.114515","DOIUrl":"10.1016/j.matchar.2024.114515","url":null,"abstract":"<div><div>Shot peening (SP) is recognized for its capacity to enhance surface strength and induce compressive residual stresses (CRS). Nevertheless, quantifying the mechanical property improvements in thin shot peened layers remains challenging with traditional methods. In this study, CNT/Al-Cu-Mg composites were subjected to shot peening. The microstructure evolution of the peened layers along the layer depth direction was investigated by XRD and TEM. Meanwhile, the changes in the mechanical properties of the shot peened layers and the release rules of CRS during tensile cycling at different numbers loads were measured by an in-situ X-ray stress analyzer and a micro-tensile device in conjunction with the Von Mises stress criterion. The results showed that SP generated the nano-gradient deformation layer with nanograins size of 50–100 nm near the surface. The yield strength of the surface layer was increased from 352 MPa before SP to 435 MPa, an increase of 23.6 %. Moreover, the observation of fracture morphology indicated that SP reduced the material plasticit moderately and the agglomeration of the Al₂Cu. In addition, in the case of a certain CRS on the initial surface, the relaxation of CRS was correlated with the magnitude of applied loads and the number of cycles and couldn't occur when the applied loads is below a specific value.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114515"},"PeriodicalIF":4.8,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656824","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":"Design and control the selection of martensitic variant to simultaneously improve strength and toughness of low-carbon martensitic steel","authors":"Bo Yang ,&nbsp;Baoxi Liu ,&nbsp;Zhichao Luo ,&nbsp;Hui Yu ,&nbsp;Fuxing Yin","doi":"10.1016/j.matchar.2024.114540","DOIUrl":"10.1016/j.matchar.2024.114540","url":null,"abstract":"<div><div>In this paper, the microstructure evolution and mechanical properties of low carbon steels during direct quenched and rolling followed by water-cooled processes were studied. Two experimental steels, which were directly quenched at 900 °C (Q900) and 1000 °C (Q1000), were compared with steels that were water-cooled after rolling at the same temperatures (R900 and R1000). Microstructural analyses using EBSD and TEM revealed that rolling reduced the size of prior austenite grains (PAGs), resulting in an average width of 3.6 μm, which influenced grain boundary distributions and variant selection. The best combination of strength, ductility and toughness was obtained in R900 steel, including tensile (with the yield strength of 1304 MPa, the total elongation of 22.95 %), Charpy impact (with the impact energy at 20 °C is 182 J), and fracture toughness evaluations (with the <span><math><msub><mi>J</mi><mrow><mn>1</mn><mi>c</mi></mrow></msub></math></span> is 326.28 KJ/m²), this demonstrates that R900 steel exhibited significantly enhanced strength and ductility compared to Q900 steel. Moreover, EBSD analysis of crack propagation paths highlighted the role of high-angle grain boundaries (HAGBs) in enhancing fracture toughness by deflecting cracks. These findings underscore the critical role of PAGs size in tailoring microstructures to achieve superior mechanical properties in low carbon martensitic steels, offering insights for advanced material design and application in demanding structural and industrial contexts.</div><div><strong>Keyworks.</strong></div><div>low-carbon martensitic steel; strength and toughness; martensitic transformation; ductile-to-brittle transition phenomenon; selection of martensitic variants.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"218 ","pages":"Article 114540"},"PeriodicalIF":4.8,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656756","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}