Article
Metallurgy & Metallurgical Engineering
Geng Tian, Zhen Li, Shun Yao, Rongjian Qie, Yifu Cui, Aimin Zhao
Summary: A high-strength medium Mn steel is produced through intercritical annealing and quenching processes. The steel composition used in the experiment is Fe-0.2C-8.0Mn-1.6Si-1.3Al (wt%). The resulting microstructures consist of ferrite/martensite and retained austenite phases. The carbon and manganese partitioning behavior during the intercritical annealing process is simulated using DICTRA. The sample annealed at 700 degrees C for 10 minutes exhibits the best mechanical properties, with a strength and elongation product of 47.25 GPa%.
STEEL RESEARCH INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
Qinyi Guo, Hung-Wei Yen, Haiwen Luo, Simon P. Ringer
Summary: Through numerical simulation and experimental comparison, this study found that solute manganese in medium manganese steel can rapidly partition to near-equilibrium concentration values during short intercritical annealing, and proposed a new concept of fluctuational interface mobility at the austenite/ferrite interface.
Article
Materials Science, Multidisciplinary
Chang Tian, Hui Guo, Masato Enomoto, Chengjia Shang
Summary: The evolution of Cu particles in Cu-bearing Mn steel was studied, showing that most Cu particles were formed in the martensite matrix during heating to annealing temperature. Calculation indicated that Cu particles in annealed martensite were likely incorporated into reversed austenite with the migration of alpha/gamma interface during annealing.
MATERIALS CHARACTERIZATION
(2022)
Article
Materials Science, Multidisciplinary
Zhihui Liao, Ying Dong, Yu Du, Xiaonan Wang, Min Qi, Hongyan Wu, Xiuhua Gao, Linxiu Du
Summary: A shortened process of ultra-fast cooling and two-step intercritical annealing for medium-Mn and low-Ni steel after rolling was designed by replacing Ni with Mn. The microstructures and mechanical properties of the experimental steel were characterized and investigated. The results showed that the steel exhibited excellent mechanical properties, including high yield strength, tensile strength, total elongation, and impact energy, due to the fine grain structure and high stability of austenite enriched by Mn and Ni.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Chemistry, Physical
Anushree Dutta, Dyutiman Barman, Jayanta Das
Summary: Hardening was observed in Ni-Zr-Al ultrafine lamellar eutectic composite via nano-precipitation, with significant enhancement of strength upon annealing and stable lamellar morphology up to high temperatures. Addition of Al facilitates the formation of small precipitates in the matrix, leading to improved material performance.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Metallurgy & Metallurgical Engineering
Zhonglin Wu, Cainian Jing, Yan Feng, Zhaotong Li, Tao Lin, Jingrui Zhao
Summary: The new process can improve the elongation of medium-manganese steels. Multiple stretches destroy the original microstructure, resulting in more deformation bands and dislocation energy. Meanwhile, grain refinement and carbide precipitation lead to diffuse distribution of retained austenite, enhancing the deformation capacity of the microstructure.
STEEL RESEARCH INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
Shuai Zhao, Renbo Song, Yingchao Zhang, Weifeng Huo, Changhong Cai, Yongjin Wang
Summary: This study explores the carbide evolution behavior and mechanical property evolution mechanisms of intercritical-annealed 3Mn steel during the tempering process. The results show that appropriate tempering time can increase the elongation and tensile strength of the steel. It is observed that carbide precipitation occurs first, followed by dissolution during tempering. Abnormal degradation of mechanical properties is found at 10 minutes of tempering, while the optimal mechanical properties are achieved at 20 minutes of tempering.
MATERIALS CHARACTERIZATION
(2023)
Article
Materials Science, Multidisciplinary
J. Teixeira, M. Moreno, S. Y. P. Allain, C. Oberbillig, G. Geandier, F. Bonnet
Summary: The manufacturing of Dual-Phase steels involves crucial steps such as annealing of cold-rolled ferritepearlite (F/P) microstructure, with various metallurgical mechanisms at play. The study focuses on austenite transformation, interactions with ferrite recrystallization, and the influence of cementite composition. Different heating rates lead to different microstructure morphologies, with slow heating resulting in necklace austenite distribution and fast heating resulting in a banded topology. Thermokinetic analysis shows that heating rates affect phase transformation kinetics, with kinetic simulations helping to understand the austenite growth process.
Article
Metallurgy & Metallurgical Engineering
Thi Thanh Tram Trang, Chang-Gon Jeong, Dongwon Lee, Yoon-Uk Heo
Summary: The effect of extended intercritical annealing time on the microstructure and tensile properties of a medium Mn steel is studied. Nanosized lamellar structures consisting of tempered-alpha ' martensite and retained austenite are formed after intercritical annealing. The fraction of cementite and fresh alpha ' martensite increases with extended annealing time, leading to reduced austenite fraction after quenching.
STEEL RESEARCH INTERNATIONAL
(2023)
Article
Engineering, Industrial
Tianle Li, Shu Yan, Dayong An, Xifeng Li, Jun Chen
Summary: By adjusting the initial delta-ferrite microstructure based on cold-rolling, two types of unusual austenite transformation were investigated in a medium-Mn steel during intercritical annealing. Firstly, an increase in delta/alpha' phase interfaces promotes gamma formation. Secondly, precipitation of carbide particles from delta phase in cold-rolled samples creates a condition for subsequent gamma nucleation.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Ning Zhao, Minlong Ding, Li Lin, Yanlin He, Junxiong Wang, Ruikun Zhang, Yu Zhang, Rendong Liu, Lihui Wang, Lin Li
Summary: Two novel dual-phase steels (DH steel) were designed for automotive steel to meet increasing demands. Water quenching and isothermal bainite treatment were employed to enhance mechanical properties. The formation of intercritical austenite was influenced by carbon partitioning during transformation. The steel after water quenching showed martensite and ferrite, with higher carbon content in martensite for improved strength and higher ferrite content for enhanced plasticity. The steel after IBT treatment exhibited excellent mechanical properties with over 1000 MPa ultimate tensile strength and 22% total elongation. The matrix microstructure composition of ferrite, bainite, and retained austenite was affected by the IA transformation, with higher intercritical austenite content resulting in greater levels of bainite and retained austenite, but lower stability of retained austenite, leading to weaker transformation-induced plasticity and lower plasticity.
Article
Engineering, Industrial
Y. Q. Wang, R. H. Duan, J. Hu, Z. A. Luo, Z. Y. Ma, G. M. Xie
Summary: This study successfully improved the toughness and ductility of medium-Mn steel joints through friction stir welding and intercritical annealing. The as-annealed joints exhibited higher impact energy and elongation, which can be attributed to the high proportion of high angle boundaries and a large amount of ultra-fine reversed austenite.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Adam Skowronek, Adam Grajcar, Liwia Sozanska-Jedrasik, Krzysztof Radwanski, Krzysztof Matus, Jaroslaw Opara
Summary: This research investigates the influence of the mechanical stability of retained austenite (RA) on material properties, finding that both chemical enrichment and grain size reduction can stabilize RA. The variation of grain sizes between 0.02 and 0.15 mm³ promotes martensitic transformation, and the presence of an appropriate average size of RA is crucial to prevent transformation obstruction or significant changes.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Chemistry, Physical
Peng Wang, Weiwei Zheng, Xinpan Yu, Yanli Wang
Summary: The advantageous implications of the microstructure and volume fraction of reversed austenite for the tensile properties of super 13Cr martensitic stainless steel were investigated. The results showed that increasing the tempering temperature led to a significant increase in the content and volume fraction of reversed austenite, resulting in improved elongation and toughness.
Article
Materials Science, Multidisciplinary
Clelia Couchet, Frederic Bonnet, Julien Teixeira, Sebastien Y. P. Allain
Summary: Austenite formation in deformed ferrite/pearlite microstructure for dual-phase steels was numerically investigated. The study focused on understanding the role of interface conditions (local equilibrium with negligible partitioning-LENP-or local equilibrium with partitioning-LEP) in controlling austenite growth kinetics during intercritical annealing. Two nucleation sites were considered based on experimental observations. The regime transition from LENP to LEP was observed for austenite formed from pearlite islands during the holding stage. Three stages were identified for austenite growth from isolated carbides during the heating stage: slow growth under LEP, fast growth under LENP, and slow growth again after carbide dissolution. These regime transitions allowed coexistence of LENP and LEP interface conditions. In competition, LEP conditions hindered austenite growth while LENP interface conditions promoted it, explaining the morphogenesis of dual-phase microstructures.
Article
Metallurgy & Metallurgical Engineering
Guo-qiang Zhang, Xiao-fei He, Qian-zhen Zhang, Wen-jun Wang, Mao-qiu Wang
Summary: By adding a small amount of niobium element in carburizing steel, a uniform and fine prior austenite grain size can be obtained, resulting in a deep hardened layer and hindered austenite grain growth. This leads to lower heat treatment distortion and improved performance of the steel.
JOURNAL OF IRON AND STEEL RESEARCH INTERNATIONAL
(2021)
Article
Materials Science, Multidisciplinary
Wu Chen, Xiaofei He, Wenchao Yu, Maoqiu Wang, Kefu Yao
Summary: The effects of austenitizing temperature on the microstructure, hardness, and tensile properties of case-carburized steel were investigated after vacuum carburization and subsequent heat treatment. It was found that the experimental steel exhibited the highest fracture stress and fine microstructure at an austenitizing temperature of 840 degrees C.
Article
Materials Science, Multidisciplinary
Boning Zhang, Jie Su, Maoqiu Wang, Zhenbao Liu, Zhigang Yang, Matthias Militzer, Hao Chen
Summary: This study reveals the physical origin of hydrogen trapping at PBs and identifies new descriptors for assessing hydrogen trapping energetics. The results provide insights for the future design of hydrogen traps and HE resistant metals.
Article
Microscopy
Wu Chen, Xiaofei He, Wenchao Yu, Jie Shi, Maoqiu Wang, Kefu Yao
Summary: The microstructure and hardness of case-hardened steel were investigated after specific heat treatments, showing that the fine particle size and even distribution of retained austenite could not lower nano-hardness.
Article
Nanoscience & Nanotechnology
Xiaofei He, Maoqiu Wang, Chengfei Hu, Le Xu
Summary: Experimental results show that reducing the total oxygen content in gear steel can decrease the size of oxide inclusions and improve the fatigue resistance of materials, but these benefits may not apply when the total oxygen level is 0.0005%.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Yongming Yan, Ke Liu, Zixiang Luo, Maoqiu Wang, Xinming Wang
Summary: The case hardness and wear resistance of carburized gear steels can be improved by cryogenic treatment, with different wear mechanisms for different steel materials. Additionally, the distortion of Navy C-ring specimens underwent shrinkage before expansion during the cryogenic process, with 17Cr2Ni2MoVNb steel showing smaller distortion compared to 20Cr2Ni4A steel.
Article
Materials Science, Multidisciplinary
Yongming Yan, Zixiang Luo, Ke Liu, Chen Zhang, Maoqiu Wang, Xinming Wang
Summary: This study investigates the effects of different low temperature treatments on the microstructure and properties of 17Cr2Ni2MoVNb steel. The results show that low temperature treatment can effectively reduce the retained austenite content and increase the volume fraction of carbides, leading to improved microhardness and frictional wear properties of the material.
Article
Materials Science, Multidisciplinary
Chunhui Li, Xiaoyuan Li, Wenchao Yu, Jie Shi, Maoqiu Wang, Run Wu
Summary: This study investigates the microstructure and mechanical properties of a martensitic steel quenched at an ultra-fast cooling rate. The results show that the ultra-fast cooled specimens exhibit significantly higher tensile strength and yield strength compared to the conventionally water-cooled specimens. This improvement in strength can be attributed to dislocation strengthening.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2022)
Article
Materials Science, Multidisciplinary
Yanjun Xue, Yongming Yan, Wenchao Yu, Xiaofei He, Jie Shi, Maoqiu Wang
Summary: This study analyzed the solid solubility products of [Nb][C] and NbC precipitates in steels with different carbon content, and experimentally proved the pinning effects of NbC precipitates in gear steels after high-temperature carburizing. The results showed differences in solid solution products and precipitation behaviors between carburized case and core steels.
Article
Materials Science, Multidisciplinary
Wenchao Yu, Shipeng Zhu, Xiaofei He, Maoqiu Wang
Summary: The microstructure, mechanical properties, and very high cycle fatigue (VHCF) properties of two 2000 MPa ultrahigh-strength martensitic steels were investigated. The newly developed steel exhibited lower ultimate tensile strength but higher yield strength compared to the conventional steel. It also had higher impact toughness, fracture toughness, fatigue strength, and longer fatigue life at the same stress amplitude due to its better cleanliness, tempering at a higher temperature, lower crack growth rate, and better toughness.
MATERIALS SCIENCE AND TECHNOLOGY
(2022)
Article
Metallurgy & Metallurgical Engineering
Xiao-li Zhao, Cheng-xiang Zhang, Yong-jian Zhang, Wei-jun Hui, Xiu-ming Zhao
Summary: This study investigated the effect of Cu addition on the hydrogen-induced delayed fracture behavior of high-strength bolt steel. The addition of Cu enhanced HIDF resistance, reduced the area fraction of brittle crack initiation zone, and decreased the corrosion pit depth and corrosion rate. This was primarily due to the formation of a Cu-rich protective rust layer and slightly higher corrosion potential.
JOURNAL OF IRON AND STEEL RESEARCH INTERNATIONAL
(2023)
Article
Chemistry, Physical
Yongming Yan, Yanjun Xue, Wenchao Yu, Ke Liu, Maoqiu Wang, Xinming Wang, Liuqing Ni
Summary: This paper focuses on the effect of gear steel on distortion due to phase transformation in carburizing and quenching. The finite element method and thermo-mechanical theory were used to study the distortion behavior of carburized gear steel. The simulation results were validated by experimental data, providing a reliable basis for predicting the distortion mechanism of gear steels in carburizing and quenching.
Article
Engineering, Mechanical
Yanjun Xue, Yongming Yan, Wenchao Yu, Mingzhen Dong, Jie Shi, Maoqiu Wang
Summary: The microstructure and fatigue properties of 17Cr2Ni2MoVNb gear steel after gas carburizing and low-pressure carburizing were compared and evaluated. The carburized layer of the low-pressure carburizing specimens had fewer carbides and a higher fraction of retained austenite due to the different quenching temperature. Both gas carburizing and low-pressure carburizing specimens exhibited a fatigue limit of 980 MPa. However, the low-pressure carburizing specimens showed significantly higher fatigue strengths at a specific number of cycles under high cyclic stresses compared to the gas carburizing specimens.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Materials Science, Multidisciplinary
Wu Chen, Xiaofei He, Wenchao Yu, Jie Shi, Maoqiu Wang, Kefu Yao
Summary: This study investigated the rotating bending fatigue properties of gear steel 16CrMnH. It was found that the fatigue life increased with decreasing stress amplitude, reaching up to 10^7 cycles at stress amplitudes ranging from 1200 to 1000 MPa. The fatigue limits were independent of the fraction of retained austenite and exceeded 1000 MPa. The retained austenite did not transform into martensite after fatigue tests, but cyclic hardening of the retained austenite increased the hardness of the carburized case. Fracture surface observations indicated that fatigue cracks initiated at non-metallic inclusions or the matrix in the carburized case.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2022)
Article
Materials Science, Multidisciplinary
Zhiqi Xie, Weijun Hui, Saiyihan Bai, Yongjian Zhang, Xiaoli Zhao
Summary: The impact fracture behavior of a Fe-25Mn-10Al-1.1C austenitic low-density steel was studied under two solution treatment temperatures. The presence of alpha + kappa-carbides at austenite grain boundaries resulted in a significant difference in V-notch impact energy between the samples treated at 800 degrees C (S8 sample) and 1000 degrees C (S10 sample), with values of 16.8 and 67.0 J, respectively. Differences in deformation characteristics, grain boundary precipitation of carbides, and the proportion of high-angle grain boundaries (HAGBs) and twins were identified as the main reasons for the disparity in impact toughness. The relatively low impact energy of the S10 sample compared to other high-Mn steels was also discussed.
JOURNAL OF MATERIALS SCIENCE
(2023)
