Acceptable Hardness Value for Carbon Steels

[arcpro]

What are the acceptable limits of hardness value in HB for carbon steels?

[ashfaqanwer]

For which carbon steel you are talking about?
Carbon content?

[arcpro]

In the carbon steel we are dealing with the maximum carbon content is 0.18%.

[qaisarabbas]

After PWHT, the Max. Limits of Hardness values for both Weld and HAZ areas are mentioned in Exxon's Basic Practices (BP-3-18-1), and these are given as:

a) 225 HB for P-1, P-3, P-4, P-10, P-11 Materials
b) 235 HB for P-5, P-6, P-7

The referred document also contains valuable information related to piping fabrication in shop & field.

Regards - Qaisar

[arcpro]

Thanks Qaisar.
Anything below 225 HB for carbon steel weld and HAZ area is acceptable?
We have the values in the range of 110-130 HB on wled, HAZ and even on the base metal.