Flame Cutting Question 2

[Carburize]

When cutting heavy plate, 10-inch thickness, I have run into a problem with surface appearance on some of the cuts - the top ( nearest the torch) 2/3 of the cut has a good smooth profile but the bottom 1/3 has deep scallops up to 3/8-inch deep in the surface.
Any suggestions on what to check first?
1) Speed?
2) Oxygen pressure?
3) Fuel gas pressure?

 

[CWIC]

What your describing is typically associated with excessive cutting speeds for the thickness. I would first try slowing down the travel speed of the torch. For that thickness travel speed is much more critical than on relatively thin materials.

By the way, which fuel gas are you using?

 

[Rich2001]

Here is a link to a publication that has speed & pressure, nozzle size for various thicknesses

http://www.thermadyne.com/vec/literature/pdfs/102-105_65-2007.pdf