Carburizing

Carburizing is a case hardening process: you introduce carbon into the surface layer of steel so that it can be hardened later. This usually happens in a carbon-donating medium, such as carburizing powder or a carbon-rich atmosphere. When welding, carburizing is generally undesirable. If the weld or heat-affected zone picks up carbon, the structure becomes hard and brittle, which can lead to cracks. You often see this on dirty workpieces, for example when oil, paint, or other carbon carriers get into the weld zone. For the workshop, this means: thoroughly clean the surface before welding. If you want to carburize deliberately, you need to set the temperature and time in the process precisely, otherwise, the result won't be good. But as a welder, you're usually more concerned with avoiding unwanted carburization.