| Abstract: | A total of more than 150 experimental heats was tested, and the results pointout that in order to improve the properties of side-blown Bessemer steel, thefollowing facts should be considered: 1) Normal temperature mechanical test results of side-blown basic Bessemersteel are higher than the lower limits enumerated for group A, steels in the Stan-dard Specifications of the Ministry of Metallurgy. However, due to the highernitrogen content, averaging about 0.008%, such steel is obviously nonfavorable ascompared with acid Bessemer as well as basic open-hearth steels with respect tosuch properties as strain-aging, blue-brittleness and sub-zero behaviors. The pre-vious usage of chemical specifications of open-hearth steel to side-blown basicbessemer steel is evidently impractical, as the influence of nitrogen content in thelatter is unduly neglected. In the present paper, a suggestion is made for modi-fying the chemical specification of basic Bessemer steel. 2) Nitrogen and non-metallic inclusions noticeably affect the properties of steel.When the depth of blowing is kept unchanged, content of nitrogen and non-metallic inclusion depend, to a large extend, upon the amount of residuel carbonat the end point of blowing. The present paper further suggests that in the future,the practice of blowing to too low a carbon content with subsequent recarburizingin the laddle should be avoided. |
