A Study of Weld Cracking of Austenitic Stainless Steel (Report 1)

FISCO Type Cracking Test (Part 1)

Abstract

With the purpose of studying the weld metal cracking of AISI Type 347 austenitic stainless steel which is essential for nuclear applications, modified FISCO type cracking tests were performed with combinations of plate thickness. 12mm and coated electrodes of several types. In the present paper, the relationship between test conditions and cracking tendencies were mainly investigated and the test procedure in the present report was a little different from the original proposed by Dr. Schnadt. The con-clusions obtained are summarized as follows :
(1) It was cleared that the modified FISCO type crack test was adequate for weld metal cracking test of austenitic stainless steel.
(2) The crack at the start of a weld bead was propagated with an increase of welding speed or root opening.
(3) The crack at the crater of a weld bead was propagated with an increase of welding current or arc voltage.
(4) The bead cracking tendency was remarkably increased with a decrease of welding heat input and the crack was finally extended along the whole length of the bead.
This tendency remarkably affected by shape of groove, root opening, type of electrode and etc.
(5) There was considerable diffirence in cracking susceptibility among the tested several electrodes of Type 347 and Croloy 16Cr-8Ni-2Mo, the latter electrode showed less susceptibility than Type 347.