Magnetic performance and microstructure characterisation of powder metallurgy Fe–6.5 wt-% Si high-silicon steel

ABSTRACT

Powder metallurgy high-silicon steel strip (Fe–6.5 wt-% Si) was prepared by directly sintering followed by rolling using gas atomised powder with low oxygen content. Due to its poor formability, the gas atomised powder was directly sintered with something heavy of 1 kg overlaid on powder top. The relative density of sintered samples was about 94.1% and the porosity was 5.9%. The pore pinning effect prevented the formation of extremely large grains during sintering, which was beneficial for subsequent rolling. The grain size was controlled in the range of 100–300 μm. After cold rolling, a large number of sub-grain boundaries and deformation bands were generated, which increased the strength to 1190 MPa. It was worth noting that these two would disappear after annealing. Instead, ordered B2 and D0₃ phases were formed, and the texture of high-silicon steel was mainly {100}<110>. A low iron loss W10/50 value of 0.55 W kg⁻¹ was achieved.

KEYWORDS:

• High-silicon steel
• gas atomised powder
• deformation bands
• ordered phase
• iron loss

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Guangdong MEPP Fund, China [grant number GDOE[2019]A16], the Fundamental Research Funds for the Central Universities, China [grant number FRF-GF-19-034B], the National Natural Science Foundation of China [grant number No. 52004027], the Scientific and Technological Innovation Foundation of Foshan, USTB, China [grant number No. BK21BE001] and the State Key Lab of Advanced Metals and Materials [grant number No. 2019-ZD08, 2020-Z17].

Notes on contributors

Qian Qin

Qian Qin is PhD candidate in Engineering at the University of Science and Technology Beijing. She is engaged in the researches on powder metallurgy iron-based materials.

Guangbang Li

Guangbang Li works as an engineer in Ansteel Iron and Steel Research Institue, Anshan, China. She is engaged in the industrial production of iron-based materials.

Fang Yang

Fang Yang is a PhD in Engineering and works as an associate professor at the University of Science and Technology Beijing. Her research interests include powder metallurgy titanium and titanium alloys, aluminum and aluminum alloys, copper and copper alloys, 3D printing, iron-based alloys, self-propagating high temperature synthesis (SHS), and magnetic materials.

Pei Li

Pei Li is PhD candidate in Engineering at the University of Science and Technology Beijing. He is engaged in the researches on powder metallurgy materials.

Cunguang Chen

Cunguang Chen is a PhD in Engineering and works as lecturer at the University of Science and Technology Beijing. His research interests include powder metallurgy titanium and titanium alloys, aluminum and aluminum alloys, copper and copper alloys, and other advanced powder metallurgy technologies and materials.

Junjie Hao

Junjie Hao is a Professor and PhD supervisor working at the University of Science and Technology Beijing. He is an expert in powder metallurgy ceramic materials, iron-based alloys, radio frequency inductively coupled plasma spheroidization technology, and advanced powder metallurgy technologies and materials.

Zhimeng Guo

Zhimeng Guo is a Professor and PhD supervisor working at the University of Science and Technology Beijing. He is an expert in powder metallurgy titanium and titanium alloys, aluminum and aluminum alloys, copper and copper alloys, 3D printing, iron-based alloys, dispersion strengthened materials, radio frequency inductively coupled plasma spheroidization technology, self-propagating high temperature synthesis (SHS), advanced powder metallurgy technologies and materials.