How much do you know about the laminar tear resistance of Z-directed steel

In fact, Z-directed steel is not a Z-shaped steel, but a thick steel with good tensile strength in the thickness direction. Its thickness is generally not less than 40mm.

Compared with ordinary thick steel plate, Z-directed steel has a more prominent difference in that it has good laminar tear resistance. It can be divided into three categories according to the location where the Z-directed steel layer tear occurs.

1. Lamellar tear induced by cold cracks at the welding toe or root of the welding heat affected zone;

2. Cracking along the inclusions in the welding heat affected zone is a common layered tear in the project;

3. Cracking along the inclusions in the base material away from the heat-affected zone, this situation occurs mostly in the thick plate structure with more Ms sheet-like inclusions.

Lamellar tearing mainly occurs in the welding of thick plates of low-alloy high-strength steel. Z-directed steel is mainly used for steel plates of some important welded components such as shipbuilding, offshore oil production platforms, boilers, pressure vessels and high-rise buildings.