检索结果-南通市图书馆

Calculation of austenite formation Kinetics of Copper-Bearing Steel During Continuous Heating

Journal of Iron and Steel Research International 2010年第11期17卷 62-66页

作者： LI Dan MIN Yong-an WU Xiao-chun School of Materials Science and Engineering Shanghai University Shanghai 200072 China

The kinetics of austenite formation in a new type of copper-bearing steel with initial microstructure composed of ferrite and bainite was investigated by using dilatometric analysis and measurement during continuous heating. The formation of austenite was observed to occur in two stages. The first stage is the dissolution of ferrite and most bainite, followed by the second stage of dissolution of bainite and formation of austenite. The first stage takes place through diffusion and the second stage through shear. The critical temperature of austenite formation during continuous heating increases with increasing heating rates, which therefore exerts a greater influence on the Ast temperature of the austenite formation. Kinetics calculation shows that the process is mainly controlled by diffusion when the heating rate is over 1℃/s.

关键词： copper-bearing steel austenite formation continuous heating kinetics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Micro-scale Cellular Automaton Modeling of Interface Evolution During Reaustenitization from Pearlite Structure in Steels

引用

Acta Metallurgica Sinica(English Letters) 2018年第7期31卷 713-722页

作者： Gang Shen Cheng-Wu Zheng Jian-Feng Gu Dian-Zhong Li Institute of Materials Modification and Modelling School of Materials Science and Engineering Shanghai Jiao Tong University Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Materials Genome Initiative Center Shanghai Jiao Tong University Shanghai Key Laboratory of Materials Laser Processing and Modification Shanghai Jiao Tong University

A modified cellular automaton model is developed to depict the interface evolution inside the cementite plus ferrite lamellar microstructures during the reaustenitization of a pearlite steel. In this model, migrations of both the austenite- ferrite and austenite-cementite interfaces coupled with the carbon diffusion and redistribution are integrated. The capil- laxity effect derived from local interface curvatures is also carefully considered by involving the concentration given by the phase diagram modified by the Gibbs-Thomson effect. This allows the interface evolution from a transient state to a steady state under different annealing conditions and various interlamellar spacings to be simulated. The proposed cellular automaton approach could be readily used to describe the kinetics of austenite formation from the lamellar pearlites and virtually reveal the kinematics of the moving interfaces from the microstructural aspect.

关键词： austenite formation Lamellar pearlite Interface evolution Cellular automaton Microstructural modeling

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of initial microstructure and grain size on transformation of bainite to austenite in large size forgings

引用

Journal of Iron and Steel Research International 2018年第5期25卷 554-562页

作者： Emna Ben Fredj Hadi Ghasemi Nanesa Mohammad Jahazi Jean-Benoit Morin Department of Mechanical Engineering Ecole deTechnologie Superieure Montreal QC H3C 1K3 Canada Finkl Steel-Sorel St-Joseph-de-Sorel QC J3R 3M8 Canada

The kinetics of austenite formation in the surface and center regions of a 40 t forged ingot of a high-strength medium- carbon low-alloy steel was studied using high-resolution dilatometry. The starting microstructures from the surface or center regions had different proportions of bainite and residual austenite as well as different prior austenite grain sizes. Two heating rates representing the actual heating rates in the surface （5℃ s -1） and center regions （0.5℃ s -1） of large size forged blocks were utilized. Dilatometric curves revealed only one transformation step of austenite formation at both heating rates independent of grain size or proportion of phases. Optical microscopy, field emission gun scanning electron microscopy and X-ray diffraction were used to study microstructure evolution and confirm the results obtained by dilatometry. The kinetic parameters for austenite formation were determined from the dilatometry data by Johnson-Mehl- Avrami-Kolmogorov （JMAK） equation. The JMAK coefficients were determined for each condition of the investigated steels. The calculations indicated that the nucleation and growth of austenite in the surface region were accelerated more than 10,000 times due to a significantly smaller average prior austenite grain size, stability of initial retained austenite, and accumulation of coarse carbides at the surface. The results were discussed in the framework of classical nucleation and growth theories using the kinetic parameters for austenite formation.

关键词： Large size ingot Medium-carbon low-alloy steel Initial microstructure Grain size austenite formation

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microstructure Characterization and Mechanical Properties of TRIP-aided Steel under Rapid Heating for Different Holding Time

引用

Journal of Iron and Steel Research International 2016年第2期23卷 138-144页

作者： De-chao XU Yan-dong LIU Jun LI Qing-ge MENG Pei LI School of Materials and Metallurgy Northeastern UniversityShenyang 110819LiaoningChina Central Research Institute of Baosteel Shanghai 201900China Shanghai JiaoTong University Shanghai 200240China

In order to develop a comprehensive understanding about the effect of different holding time under rapid heating on the microstructural evolution and mechanical properties of transformation-induced plasticity （TRIP） steel, continuous annealing process simulations were performed using a thermal system with resistance heating method. The morphology and distribution of all phases present in the microstructure and the mechanical properties of TRIP steel were revealed. It appeared that the final tensile strength of the TRIP steel increased and retained austenite car bon content decreased with increasing holding time. An overlap between ferrite recrystallization and austenitization was observed during intercritical holding. In addition, the work hardening of the samples was evaluated by calculat ing the instantaneous ~l value as a function of the true strain. The difference in work hardening behavior corresponds to the rate of the retained austenite transformation during straining, which can be attributed to the carbon content and the morphology of the retained austenite.

关键词： TRIP-aided steel rapid heating holding time austenite formation retained austenite

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：