Hydrogen-Assisted Cracking in GMA Welding of High-Strength Structural Steel—A New Look into This Issue at Narrow Groove

Abstract

Modern arc processes, such as the modified spray arc (Mod. SA), have been developed for gas metal arc welding of high-strength structural steels with which even narrow weld seams can be welded. High-strength joints are subjected to increasingly stringent requirements in terms of welding processing and the resulting component performance. In the present work, this challenge is to be met by clarifying the influences on hydrogen-assisted cracking (HAC) in a high-strength structural steel S960QL. Adapted samples analogous to the self-restraint TEKKEN test are used and analyzed with respect to crack formation, microstructure, diffusible hydrogen concentration and residual stresses. The variation of the seam opening angle of the test seams is between 30° and 60°. To prevent HAC, the effectiveness of a dehydrogenation heat treatment (DHT) from the welding heat is investigated. As a result, the weld metals produced at reduced weld opening angle show slightly higher hydrogen concentrations on average. In addition, increased micro- as well as macro-crack formation can be observed on these weld metal samples. On all samples without DHT, cracks in the root notch occur due to HAC, which can be prevented by DHT immediately after welding.

Influence of Preheating Temperature on Structural and Mechanical Properties of a Laser-Welded MMC Cobalt Based Coating Reinforced by TiC and PCD Particles

“…In the case of the composite tested, this condition was met for the preheating temperature of 300 • C. To obtain a crack-free surfaced coating, it was necessary to select the preheating temperature and control the inter-pass temperature. Preheating the material before surfacing reduces shrinkage stress [39] and the hardness in the heat-affected zone [40], while also reducing the risk of hydrogen cracks [41]. In the analyzed case, the factors that influenced the necessity to use preheating were the high carbon equivalent value, CEV = 0.66% and the high-power density of the heat source, which translated into low linear welding energy.…”

Application Possibilities of the S960 Steel in Underwater Welded Structures

“…This area of cracking is typical for underwater processes [16,18]. Furthermore, Schaupp et al [35] in their next paper showed that S960 UGSS is characterized by a high risk for hydrogen-assisted cracking both in the weld metal and in the HAZ. These investigations suggest that the S960 steel may be characterized by very high susceptibility to cold cracking in underwater conditions, due to a high amount of water during joining in this environment.…”

Analysis of Hydrogen Embrittlement on Aluminum Alloys for Vehicle-Mounted Hydrogen Storage Tanks: A Review

“…More and more attention has been paid to the safety of transportation equipment [1][2][3]. Facing the energy crisis, hydrogen-fueled vehicles are recognized as a most promising solution [4][5][6][7]. Compared with electric vehicles, when refueling with energy, the hydrogen vehicle has advantages of technical simplicity and high filling rates [8].…”

“…It is widely accepted that hydrogen embrittlement (HE) has become a serious problem since high-strength steel became widely used [5,7,13,14]. With the widespread application of aluminum alloys, it's found that aluminum and its alloys also have a higher hydrogen content [15][16][17].…”