Microstructure and properties of fine grain IN718 alloy bar products produced by continuous rolling

The newly imported high-alloy steel continuous rolling line in Baoshan Iron & Steel Co. Ltd, which is the first production line in China, was introduced in this paper. The 14 ~ 55mm diameter bar hot-rolling procedure has been refined after studying the influences of processing parameters such as micro-structure of continuous rolling billet, rolling start temperature, continuous rolling deformation ratio, rolling line rate, and control cooling parameters on microstructure and properties of IN718 bars. In comparison with traditional open-train mill, this continuous rolling technology provides fine grain bar products with uniform grain structure and reasonable distribution of δ
phase. Grain size of bar products can be controlled at ASTM 10 in the center and ASTM 11 ~ 11.5 near the surface by means of this technology. Now this technology is in a stable production condition and the bar products produced provide excellent mechanical properties. (AU) © 2010 by The Materials, Metals, & Materials Society. All rights reserved.