Lamellar tearing, Weld Cracking, weld failure #shorts

#Lamellar tearing.
Lamellar tearing occurs only in rolled steel products (primarily plates) and its
main distinguishing feature is that the cracking has a terraced appearance.
Cracking occurs in joints where:
A thermal contraction strain occurs in #through-thickness direction of
steel plate.
Non-metallic inclusions are present as very thin platelets, with their
principal planes parallel to the plate surface.
Figure 3.7 Diagram of lamellar tearing.
Contraction strain imposed on the planar non-metallic #inclusions results in
progressive decohesion to form the roughly rectangular holes which are the
horizontal parts of the cracking, parallel to the plate surface. With further
#strain, the vertical parts of the cracking are produced, generally by ductile
shear cracking. These two stages create the terraced appearance of these
cracks.
Two main options are available to control the problem in welded joints liable to
#lamellar tearing:
1 Use a clean steel with guaranteed through-thickness properties (Z grade).
2 A combination of joint design, restraint control and welding sequence to
minimise the risk of cracking.

Lamellar tearing
A type of #cracking that occurs only in steel plate or other rolled products
underneath a weld, in the through-thickness direction of steel plate.
Characteristics of lamellar tearing are:
Cracks only occur in the rolled products eg plate and sections.
Most common in C-Mn steels.
Cracks usually form close to but just outside, the HAZ.
Cracks tend to lie parallel to the surface of the material and the fusion
boundary of the weld having a stepped aspect.