Effect of Electrode Types on the Solidification Cracking Susceptibility of Austenitic Stainless Steel Weldment

ABSTRACT

The effect of electrode types on the solidification cracking susceptibility of austenitic stainless steel weld metal was studied. The work also investigated the effect of electrode types on the strain hardening exponent of austenitic stainless steel welded joints. Manual metal arc welding method was used to produce the joints with the tungsten inert gas (TIG) welding serving as the control. Tensile tests and metallography of the joints were carried out using standard techniques. Chemical analyses of the fusion zones of the joints were conducted. The results indicate that weldments produced from E 308 –16 (gauges 10 and 12, rutile coated

electrodes), E 308 – 16 (gauge 12, lime-titania coated electrode) and TIG welded joints fall

Ni.e.q
equivalents respectively. The E 308 – 16 (gauge 12, lime-titania coated electrode) weld had

the greatest resistance to solidification cracking. The welded joints produced from E 310 – 16

Ni.e.q
susceptible to solidification cracking. The E 312 – 16 (gauge 10 electrode) produced welded

Cr
joints having .eq. ratio > 1.9 and solidified with a ferrite mode.

Ni.e.q
This weld had a low resistance to solidification cracking. The values of the strain hardening

exponent and tensile strength of the welded joints were 0.379 and 475N/mm2 for E 308-16 (gauge 10, rutile coated) electrode; 0.406 and 425N/mm2 for E 308-16 (gauge 12, rutile coated) electrode; 0.382 and 425N/mm2 for TIG welding; 0.353 and 517N/mm2 for E 308–16 (gauge 12, lime-titania coated) electrode; 0.435 and 508N/mm2 for E 310-16 (gauge 10, rutile coated) electrode and 0.396 and 525 N/mm2 for E 312-16 (gauge 10, rutile coated) electrode. E 310 – 16 (gauge 10 electrode) had the greatest strength and strain hardening coefficients of 1180N/mm2 and 0.435 respectively, and was recommended for welded joints when high formability is desirable. Also, the E 312 – 16 (gauge 10 electrode) was recommended for welded joints when tensile strength is very desirable.

Keywords: Austenitic stainless steel, solidification cracking, electrode type, welding, strain hardening coefficient.