NACE HAZ Duplex: Understanding Welding Qualification Requirements

Introduction

If you’re working with duplex stainless steels, it’s essential to understand the welding qualification requirements outlined in ISO 15156/NACE MR0175 part 3, A.7.3. In this article, we’ll answer some common questions related to welding qualification and provide information on how OGC Energy can help you meet NACE MR0175 requirements.

Question 1: Is There a Hardness Limit for Welds in NACE MR0175/ISO 15156?

One of the most common questions we receive is whether there is a hardness limit for welds in NACE MR0175/ISO 15156. Specifically, Table A.24’s lack of a hardness limit for solution-annealed and liquid-quenched or rapidly cooled duplex stainless steels can be confusing.

The answer is that there is no defined hardness limit for the HAZ used for qualification of the welds in NACE MR0175/ISO 15156. However, there are cracking mechanisms defined in the document that must be considered. If you have questions about these mechanisms or need help defining requirements for other properties outside of hardness limits for welds, the team at OGC Energy can help.

Question 2: Do Hardness Limits in Relevant ASTM Standards Apply?

Another common question we receive is whether hardness limits in relevant ASTM standards apply to welding qualification requirements in NACE MR0175/ISO 15156. The answer is that advice on which other standard(s) may apply for a particular product is not covered by NACE MR0175/ISO 15156.

At OGC Energy, we specialize in helping clients resolve queries related to the qualification of duplex and super duplex stainless steel and their welding qualification to meet NACE MR0175 requirements and comply with other standards such as DNV RP F112. Contact us today to learn more!