Heat-Affected-Zone Liquation Cracking in Welded Cast Haynes® 282®

Abstract

Varestraint weldability testing and Gleeble thermomechanical simulation of the newly developed cast form of Haynes® 282® were performed to understand how heat-affected-zone (HAZ) liquation cracking is influenced by different preweld heat treatments. In contrast to common understanding, cracking susceptibility did not improve with a higher degree of homogenization achieved at a higher heat-treatment temperature. Heat treatments with a 4 h dwell time at 1120 °C and 1160 °C exhibited low cracking sensitivity, whereas by increasing the temperature to 1190 °C, the cracking was exacerbated. Nanosecond ion mass spectrometry analysis was done to characterize B segregation at grain boundaries that the 1190 °C heat treatment indicated to be liberated from the dissolution of C–B rich precipitates.

Welding Metallurgy and Weldability of Superalloys

“…Researchers were invited to submit innovative research papers in the areas of welding metallurgy, weldability, and associated topics of superalloys. In total, six research papers were published in this Special Issue of Metals, entitled "Welding Metallurgy and Weldability of Superalloys", which presents some of the research trends in the field [1][2][3][4][5][6]. All six research papers were related to weld cracking in some aspect, with the strongest focus on hot cracking [1][2][3][4]6], followed by strain age cracking [5].…”

“…In total, six research papers were published in this Special Issue of Metals, entitled "Welding Metallurgy and Weldability of Superalloys", which presents some of the research trends in the field [1][2][3][4][5][6]. All six research papers were related to weld cracking in some aspect, with the strongest focus on hot cracking [1][2][3][4]6], followed by strain age cracking [5]. The major part of the submission in terms of material was associated with Alloy 718, the "work horse" within the group of superalloys in the aero-engine industry [2][3][4].…”

“…In addition, Haynes ® 282 ® , a superalloy that falls into the same class of superalloys (i.e. precipitation hardening Ni-or Ni-Fe based superalloys) as Alloy 718 was covered in two papers that were investigated [5,6]. Varestraint weldability testing [3,4,6] was the major testing method addressed within the field of weldability testing, followed by Gleeble thermomechanical testing [5].…”

“…al. [6] studied Varestraint weldability testing as well as Gleeble thermomechanical simulation of the newly developed cast form of Haynes ® 282 ® to understand how HAZ liquation cracking is influenced by different preweld heat treatments. It was found that cracking susceptibility did not improve with a higher degree of homogenization achieved at a higher heat treatment soak temperature, in contrast, cracking was exacerbated.…”

Characterization of γ′ Precipitates in Cast Ni-Based Superalloy and Their Behaviour at High-Homologous Temperatures Studied by TEM and in Situ XRD

“…The first was the selection of the solution heat treatment temperature and time, in order to homogenise the microstructure as much as possible. The second, as several reports [30][31][32] had indicated, that superalloys strengthened by a high-volume fraction of γ precipitates are strongly susceptible to liquation cracking during welding. Some investigations [33][34][35] indicate that high temperature preheat can overcome this problem, so it is important to study the kinetics of the dissolution process to prevent this negative result.…”