Enhancing strength of an ultra-low-carbon weathering steel to 700 MPa by adjusting Ti content
Tian-en Peng1, Zhi-wei Lian1, Yuan-yang Zhang1, Bo He2, Xue-wen Hu2, Tao Zhu2, Bo Jiang1
1 School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China 2 Technical Center, Ma’anshan Iron & Steel Co., Ltd., Ma’anshan 243041, Anhui, China
Enhancing strength of an ultra-low-carbon weathering steel to 700 MPa by adjusting Ti content
Tian-en Peng1, Zhi-wei Lian1, Yuan-yang Zhang1, Bo He2, Xue-wen Hu2, Tao Zhu2, Bo Jiang1
1 School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China 2 Technical Center, Ma’anshan Iron & Steel Co., Ltd., Ma’anshan 243041, Anhui, China
摘要 The microstructure and mechanical properties of a traditional Ti-microalloyed weathering steel were analyzed, and the strength was improved by proposing an optimized Ti content. The yield strength and elongation of the steel were 640 MPa and 25.5%, respectively. The microstructure was ferrite and pearlite, and the average grain size was 5.4 lm. The precipitates were mainly TiC with the size below 20 nm, and the average diameter was 18.2 nm. The yield strength of the newly proposed weathering steel with Ti content of 0.018% higher than that of the traditional steel reached up to 709 MPa, and the elongation was 23.5%. The ferrite grain was refined to 3.8 lm, the fraction of TiC under 10 nm was obviously increased, and the average diameter of particles was 9.8 nm. The increase in Ti also promoted the recrystallization process, thus leading to the reduction in dislocation density. The yield strength of the newly proposed weathering steel was increased to higher than 700 MPa by adjusting the Ti content mainly resulting from three aspects: grain refinement, precipitation and dislocation strengthening. The contributed values were 45, 64 and –40 MPa, respectively.
Abstract：The microstructure and mechanical properties of a traditional Ti-microalloyed weathering steel were analyzed, and the strength was improved by proposing an optimized Ti content. The yield strength and elongation of the steel were 640 MPa and 25.5%, respectively. The microstructure was ferrite and pearlite, and the average grain size was 5.4 lm. The precipitates were mainly TiC with the size below 20 nm, and the average diameter was 18.2 nm. The yield strength of the newly proposed weathering steel with Ti content of 0.018% higher than that of the traditional steel reached up to 709 MPa, and the elongation was 23.5%. The ferrite grain was refined to 3.8 lm, the fraction of TiC under 10 nm was obviously increased, and the average diameter of particles was 9.8 nm. The increase in Ti also promoted the recrystallization process, thus leading to the reduction in dislocation density. The yield strength of the newly proposed weathering steel was increased to higher than 700 MPa by adjusting the Ti content mainly resulting from three aspects: grain refinement, precipitation and dislocation strengthening. The contributed values were 45, 64 and –40 MPa, respectively.
Tian-en Peng,Zhi-wei Lian,Yuan-yang Zhang, et al. Enhancing strength of an ultra-low-carbon weathering steel to 700 MPa by adjusting Ti content[J]. Journal of Iron and Steel Research International, 2023, 30(12): 2494-2504.
2023, Vol. 30 
