Study on Microstructure of directional solidified T91 steel

3rd International Conference on Advances in Energy Resources and Environment Engineering

能源学;生态环境科学

Wang, Q.S.^1 ; Wang, W.Q.^1 ; Shi, Z.M.^2

College of Materials Science and Engineering, Jilin University, No. 5988 Renmin Street, Changchun

130022, China^1

Zhejiang Industry and Trade Vocational College, No. 717 Fudong Street, Wenzhou

325002, China^2

关键词: Columnar crystals;    Crystal morphologies;    Directional microstructure;    Elastic modulus values;    Liquid metal cooling;    Solidification rate;    Solidification structure;    Thermal fatigue properties;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/113/1/012146/pdf
DOI  :  10.1088/1755-1315/113/1/012146

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

Using the method of directional solidification to prepare T91 steel is an effective way to reduce the elastic modulus and improve the thermal fatigue properties of alloy. In this paper, T91 steels were fabricated through liquid metal cooling method by the solidification rate of 30μm/s, 90μm/s and 180μm/s, and the crystal morphology was analysed. The results demonstrate that deflection angle of columnar crystals is increased with the raising of solidification rate, the maximum angle is 20 degrees, and the solidification structure is refined in general. The central solidification zone is the concentration area of directional microstructures, in which lath ferrites are arranged in parallel and the martensites are mainly distributed in the beginning and the end of the sample. The range of elastic modulus values of three specimens is 141.05∼186.73GPa, and E90μm/s180μm/s30μm/scommon cast. The thermal fatigue property of T91 obtained by directional solidification method is better than that by common casting. When the solidification rate is 90μm/s, the thermal fatigue resistance of the specimen is best, which increases by about 25%.