MS plate cracked on HAZ

[nabzzban]

Gents,
I noticed a problem on MS plate 275JR, Plates has to fold after plasma cutting and cracks occurring on HAZ. MTC accepted as per standard.

 

[metengr]

The HAZ should be removed for this material.

 

[nabzzban]

But why this is happening is it because of As Rolled !

 

[metengr]

No. The reason for the cracks in the heat affected zone (HAZ) is that the plasma cut surface and base material beneath contain a heat affected zone caused by heat and subsequent rapid cooling from cutting. The mechanical properties in the HAZ are different from the base metal, meaning lower ductility.

Remove the heat affected zone material and you should be able to fold with no problem.