Abstract
In order to examine effects of the mill arrangements on some properties of [the wire rod of mild steel and the wire drawn from it, a comparative study was made of the hot rolled wire rods produced at Hikari and Yawata plant of Yawata Iron & Steel Co., Ltd.
To quote the different points between these two works, the former is the 4-strand high speed continuous wire rod mill manufactured by Siemag Co., and the latter the semicontinuous wire rod mill (a combination of a continuous and a Garret's type mill).
The following are the chief results explained:-
1. The roundness of hot rolled rods of Hikari works was better than that of Yawata works.
2. The mill-scales on the hot rolled rods were 12mg/cm at Hikari and 25mg/cm at Yawata, respectively, and therefore the pickling time for Hikari rods was much shorter than that for Yawata's.
3. The tensile strength and the yield point of Hikari rods were higher than those of Yawata rods, though the elongation and the reduction of area were higher.
4. In point of microstructure, it was noticed that ferrite grains of Hikari rods were a bit smaller than those of Yawata's.
5. The above-mentioned characteristics of the Hikari rods presumably were caused by the effective water cooling to be applied after the rods were passed through the final rolls.
6. The mechanical properties of the wire drawn depended on the intial rod properties of the rods and chemical compositions. Therefore tensile strength of the wire drawn from Hikari rods were higher, but reduction of area of the wire were also influenced by the draw ing method, particularly with the increase of the cold reduction.
