| The tensile strength increase of the wire on wire drawing is too variable. This in turn leads to factors that effect strain hardening rate of the wire drawing. To reduce this, North Star started practicing Boron addition to low carbon steel for reducing strain hardening. It was previously assumed that the rate of gain of low carbon boron wire was similar to the low carbon non boron wire, except for the tensile drop in case of the boron. This research concludes that the Tensile Strength Gain rate is higher in case of non boron steel compared to boron steel. Regression equations were formed for each sequence on the basis of which, for a given process, final tensile strength gain values can be calculated at any desired reduction of area.; The results of this study also conclude the following: (1) Percentage Boron has the highest influence in controlling tensile strength gain value followed by the cooling rate. (2) In case of non boron steels, the combination of variables giving lowest tensile strength gain is low laying head temperature and a low stelmor cooling rate. (3) In case of boron Steels, the combination of variables giving lowest tensile strength gain is high laying head temperature, low stelmor cooling rate. (4) Boron steel shows a larger ferrite grain size and lower pearlite content compared to non-boron steel. |
