피복아크용접을 이용한 압연강재에 대한 용접성 평가에 대한 연구

A Study on the Evaluation of Weldability for Rolled Carbon Steel Using SMAW

This paper deals with evaluation of weldability for Rolled carbon steel(SS400 and SM45C) Using SMAW, in which weldability test specimens were categorized into A, B, C type, respectively, for the purpose of weldability evalution, mechanical properties of the specimens between the whiles similar and dissimilar materials were then investigated, and the results obtained through observation were macroscopically compared and analyzed. Under each experiment condition those mechanical properties of the welded specimens were furtherly analyzed for inlcluding the hardness test for each specimen by dividing the welded are the metal part, the heat affected zone, and the base part, Hardness was shown to be the highest in the heat affected zone while there was no significant difference between the welded metal and base metal. Tensile strength and yield strength values were enhanced on all the specimens. Both of macroscopic and microscopic examination revealed notable changes in the heat affected zone seen in the microscopic structure of similar and dissimilar materials. The larger the amount of carbon gets, the greater the amount of pearlite (black part) together with the excessive cementite tend to apper. The texture of the welded part was similar to that of the base material and the microstructure of the crystal grain turned out to be refined.