Quench&Tempered steels and 'oxygen gouging'

Date 01-29-2008 16:51

I think the notes in Table 3.1 and 3.2 gets you off the hook for heat input limitations on A913. So, in my opinion you can oxygen gouge A913 per the code. One could make a strong argument the other way and find some good code sections to support that view but then we are tossing logic out the door. I think the exception for A913 in Table 3.1 and 3.2 just did not get carried over to the other sections on cutting q&t material, or the text in the notes is simply incomplete.

There are 3 types of thermal cutting:
(1) Oxygen cutting
(2) High energy beam cutting
(3) Arc cutting

Oxygen gouging is categorized under #1.
Carbon-arc Cutting (and gouging) is categorized under #3.

So no, they are not the same.

By swnorris (****)

Date 01-29-2008 22:36

In my opinion, Tables 3.1 and 3.2 apply strictly to welding, as do the notes with regard to heat limitations of 5.7 not applying to A913 steel. I believe this is because the A913 steel is not as susceptable to the heat degradation generated by welding as the other quenched and tempered steels are.

Oxygen gouging and carbon arc gouging are basically two different processes. I think there's more heat input associated with oxygen gouging than with carbon arc gouging, which may be the reason that oxygen gouging is not permitted. If that's true, the heat of the steel that's generated from oxygen gouging will cool slower than that of carbon arc gouging, and slower cooling of quenched and tempered steels is not recommended.

If you're not satisfied with either of those answers, if you can find out the mill's recommendation for maximum heat input on A913, compare it to that of the carbon arc gouging process. If heat from gouging is lower than the recommendation, you may have something that you can run by the EOR.

I have no facts to base any of this on. It's all just my opinion.

By pipewelder_1999 (****)

Date 01-30-2008 02:18

Just a little added information/opinion. The temperature that the base metal gets to when oxygen gouging must be high enough to allow the metal to begin to melt. While this is happening the surrounding base metal get pretty hot. If the time at elevated temperature is sufficent then the mechanical properties can be affected.

With Air Carbon Arc gouging the base metal temp surrounding the area of gouging seldom gets hot enough for long enough to cause any damage.

Have a nice day

Gerald