YTChenghe offers a wide portfolio of solutions for all tasks within the welding industry ranging from incoming inspections of raw materials, welding rods and consumables to all kinds of pre-, in- and post-welding inspections. For example, whereas OES or XRF instruments deliver information on the exact chemical composition of the weld, micro-XRFtechniques,EDS and EBSD detectors on electron microscopes , qualify and quantify welding defects on the micrometer scale such as inclusions, the lack of fusion or local deformations.
Hydrogen-induced damage is a wide-spread and dreaded phenomenon. During welding, hydrogen is generated from the dissociation of water vapor (e.g. humidity) or hydrocarbons in the welding arc, and the molten metal can rapidly pick up hydrogen. Once in the weld metal, hydrogen atoms can diffuse swiftly into the heat-affected zone of the base metal as diffusible hydrogen. During cooling and phase transformation of the matrix, the residual hydrogen accumulates at microstructural dislocations and voids as molecular hydrogen, resulting in localized tensile stress adding to the residual tensile stresses. Diffusible hydrogen causes hydrogen induced cracking (also known as cold or delayed cracking), where components fail under the influence of mechanical stress - suddenly and without prior indication.