A Study on the Weldability of High Strength Steels

Various Weld Ductility Test Results and Effects of Manganese and Silicon

Abstract

The development and evaluation of various weldability tests and investigation of the effect of alloying contents on the weldability of Mn-Si high strength steels were performed using 12 experimental steels, with additions of 1.2% silicon and/or 1.8% manganese. The present paper describes the results of a tapered maximum hardness test, bead-bend tests and synthetic HAZ ductility test, which was newly proposed by the authors.
From above results, the main conclusions were obtained as follows:
1) From a tapered maximum hardness test, it was recognized that weld HAZ hardness was increased remarkably by manganese addition, but a little by silicon.
2) As a results of the comparison of various miniatured specimens with the longitudinal bead-bend-test specimen of Kommerell type, one small type specimen was newly introduced as a substitute for the standard type.
3) HAZ ductility which was obtained by the synthetic HAZ ductility test showed remarkable loss with increasing manganese contents but was almost unaffected by silicon contents.
4) Intimate relationships were established between the results of a small type bead-bend test and a synthetic HAZ ductility test, especially in critical hardness values which showed unsatisfactory HAZ ductility.