Effect of Nonmetallic Inclusions on Steel Welds Metal Hot Cracking

B. Z orc, W elding I nstitute, L jubljana, S lovenia; M . I mamović, Un iversity of Zenica, Faculty of Mechanical Engineering, Zenica, B a nd H; A. Nagode, B. Kosec, L. Kosec, University of Ljubljana, Faculty of Natural Sciences and Engineering, Ljubljana, Slovenia; A. Stoić, I. Samardžić, University of Osijek, Mechanical Engineering Faculty, Slavonski Brod, Croatia Intercrystally distributed nonmetallic inclusions g reatly increase weld susceptibility to hot crack ing. Oxide and sulphide inclusions are the result of contaminated base material or its highly oxidised surfaces and they can be a consequence of metallurgical reactions between welding slag and remelted base material, while carbide inclusions can occur due to the mixing of highcarbon base and low-carbon Ā ller material. All welding surfaces must thus be cleaned before welding and the least possible mixture of base with Ā ller material must be enusured during welding.