Preparation method of powder metallurgy-hot rolling gradient high silicon steel thin strip

The invention relates to a preparation method of a powder metallurgy-hot rolling gradient high-silicon steel thin strip, which comprises the following steps: 1) preparing a composite blank of five layers of materials, including 2.5-3.5 wt% of Si low-silicon steel in the middle and Fe-Si alloy powder layers which are symmetrically arranged up and down and have the same thickness, and coating the exteriors of the Fe-Si alloy powder layers with plain carbon steel plates with the thickness of 2-3mm; and (2) the gradient high-silicon steel thin strip with the thickness of 0.1-0.5 mm is manufactured through the hot rolling-assembly-hot rolling-diffusion and permeation process design. The high-silicon steel composite layer is prepared on the surface of the low-silicon steel through the powder metallurgy technology, then the gradient high-silicon steel thin strip is obtained through thermal diffusion permeation treatment, and the problems that the production efficiency is low and the environment and equipment are pol