Strain hardening, embrittlement of cracking cases
Hot problems often occur in a variety of problems, such as weld cracking, material cracking, etc. Users generally don't know what is going on. In fact, the heat process can also cause cracking, because the material becomes "brittle" during heat. In the most typical case, in the case of perforated components, the steel cracks along the perforated position during hot-dip galvanizing:
This type of cracking at the position of the perforation or edge of the galvanized steel sheet, when hot-dip galvanized, is a brittle stress-aged crack.
Causes of vine aging cracking
In the galvanizing process, there are two possible cases of stress aging fracture:
Before galvanizing, stress must be "introduced". Cold working operations, such as punching, grooving, shearing, and severe bending, can cause "stress" within the steel. If stress relief is not applied before galvanizing, the stress introduced into the material during the galvanizing process will translate into high local residual stresses and result in stress aging brittleness.
Strain-aging brittleness can also be caused by inclusions in the steel, such as brittle fractures that occur in some of the lower quality steels used in steel bars (such as milled steel) when they are bent at the processing site.
In the process of punching into a thicker section, repeated bending or bending of the galvanized steel sheet with a smaller core radius results in an increase in cold working stress. If a part cracks due to strain aging, this cracking usually occurs directly after hot plating, but for steel bars, it can also occur at the construction site, even if it is simply a stress generated by handling, it is enough to cause tension. Aged brittle cracking.
Cracking of steel occurs shortly after hot plating is completed, which is the biggest difference between strain aging embrittlement and hydrogen embrittlement.
