Sulphide and Its Effect on Solidification Cracking in Weld Metal of Steel (Report 6)

Effects of carbon and nickel on the shape of sulphide and the microsegregation of sulphur in TIG-arc weld metals of Fe-S-C and Fe-S-Ni alloys have been investigated. In these alloys the sulphur contents were purposefully made much higher than those encountered in commercial steels. For the evaluation of the microsegregation the amount of sulphides was measured with the point counting method. Main conclusions obtained are as follows:1) Dihedral angle of sulphide somewhat increases as carbon content increases. On the other hand an increase in nickel content slightly decreases it.2) Microsegregation of sulphur during weld solidification increases as carbon or nickel content increases.3) Nickelsulphide was not detected in weld metal containing up to about 11% nickel.