Laminar Tearing
Definition
Step-like fracture in the base plate beneath a restrained weld, propagating along planes of MnS inclusion stringers aligned with the rolling direction under through-thickness tensile stress from weld shrinkage.
- Appearance
- Step-like fracture in base plate
- Cause
- Through-thickness tensile stress from weld shrinkage
- Propagation path
- Along MnS inclusion stringers
- Orientation factor
- Stringers aligned with rolling direction
Common questions
How does laminar tearing differ from lack of fusion as a weld failure mode?+
Laminar tearing occurs in the base metal beneath a restrained joint, driven by inclusions inherited from the plate's rolling process, while lack of fusion is a defect within the weld itself where the weld metal fails to bond to adjacent metal.
Why does plate orientation matter for laminar tearing risk?+
Through-thickness tensile stress from weld shrinkage pulls perpendicular to the rolling direction, and since MnS stringers are elongated along that rolling direction, a joint design loading the plate through its thickness is far more susceptible than one loading it in-plane.
Related terms
- Hot Cracking
- Solidification cracking or liquation cracking that occurs at elevated temperature during or just after welding. Driven by liquid films of low-melting impurity...
- Hydrogen Cold Cracking (HCC)
- Delayed intergranular cracking in the heat-affected zone or weld metal, caused by atomic hydrogen absorbed during welding, susceptible martensite microstructure, and residual...
- Lack of Fusion (LOF)
- A planar weld defect where the weld metal fails to fuse to the base metal or to the adjacent weld pass. Essentially...
- Phased-Array Ultrasonic Testing (PAUT)
- Advanced ultrasonic inspection using a multi-element probe whose beam angle and focal depth are electronically controlled to scan a weld volume systematically....
- Porosity
- Gas-filled voids in weld metal or castings, spherical or elongated (wormhole/piping), caused by dissolved gas evolving during solidification. Reduces cross-section and acts...