Experimental study of the creep behavior of parent, simulated HAZ and weld materials for cold-drawn 304L stainless steel

In this paper, the creep behavior and constitutive equations of different layers of the weldment for cold-drawn 304L stainless steel have been determined using experimental data. This alloy can be used in the “as-welded” condition, even in severe corrosive conditions due to its lower carbon, which minimizes both chromium carbide precipitation and intergranular corrosion during the welding. As a result, welded Austenitic Stainless Steel 304L joints have extensive application in power generation and petrochemical industries and it is critical to study their high temperature creep resistance. For this purpose, test samples have been obtained from cold drawn bars, simulated HAZ and weld material according to the ASTM A276-05a. The creep behavior and properties have been examined for these materials by conducting uni-axial creep tests. Constant temperatures and constant load uni-axial creep tests have been carried out at three temperatures of 680, 700 and 720 °C, subjected to constant loads, which produce initial stresses ranging from 140 to 360 MPa that are either below or above yield. The experimental data have been used to obtain the creep constitutive parameters using numerical optimization techniques. In addition, the temperature and stress dependency of the creep properties for Parent, HAZ and Weld materials have been investigated using Larson–Miller and Monkman–Grant parameters.

► Creep constitutive parameters for CD 304L SS weldment are calculated experimentally.
► The time to reach 3% creep strain is lowest for the HAZ and is highest amount for the weld.
► The minimum creep strain rate is lowest for the weld and is highest amount for the HAZ.
► HAZ layer has the shortest creep lifetime if one considers the creep lifetime as the time to reach a certain strain level.