Crystallization Temperature Interval
The temperature range between the liquidus and solidus lines where the weld metal changes from liquid to solid. A wide interval increases susceptibility to solidification cracking.
Physico-Chemical Mechanism of Action
The crystallization temperature interval is the range between liquidus (temperature at which the weld metal becomes fully liquid) and solidus (temperature at which it becomes fully solid). In this interval, the liquid parts of the weld pool crystallize into solids.
Metallurgical Relevance & Welding Risks
A wide crystallization temperature interval increases susceptibility to solidification cracking. This is because the weld metal cools slowly in this range and crystallizes into solid grains. This can lead to uneven solidification and stress buildup, which can cause cracks.
Workshop Practice & Action Guidelines
To minimize solidification cracking, the weld metal should be passed through the crystallization temperature range as quickly as possible. This can be achieved by an optimal heating rate and careful cooling. The exact temperature and time must be determined depending on the materials and welding process used.