Ice Flower Like Structure in Metal by Arc Welding, in Particular Mild steel (Report 2)

Effects of chemical composition on the formation of ice flower like structure

Abstract

Referring to ice flower like structure, many studies and contributions have been widely announced and published. Cooling velocity, existence of, impurities, stresses, deoxidizing condition, embrittle-ment and shapes of bead are said to be the main factors of tits formation. Some of these are acceptable as the factors, but they are not sufficient to explain the formation of ice flower like itrructure.
This report refers to the effect of the chemical composition of the deposited metal and the cooling velocity.
The first experiment was to investigate the influence of chemical compositions of core wire upon the formation of ice flower like structure. Considering the experimental results, Si-rich core wire, with the same coating materials used for any content of Si, can be said to have more tendency to form ice flower like structure.
The second experiment was performed using approximately 60 kinds of coated electrodes for mild steel. The relation between the chemical compositions of the deposited metals and the forma-tion of ice flower like structure was studied. Figure 5 indicates the value of Mn, Si and C of Table 5 and other references. It was certified that the ice flower like structures are frequently formed when the deposited metal is rich in Si as compared with Mn and C.
Next, further investigations were performed using the electrodes coated with different amounts of these elements (Si-Mn-C). The relation as shown is Fig. 9 was obtained. Considering from the results, it was clarified that Si-rich coating materials give rise to ice flower like structure.
Moreover, a few results were given as supplement to the first report concerning the influence of the cooling velocity upon the formation of ice flower like structure. The proper cooling velocity to produce the columnar crystals is essential for the formation of ice flower like structure.