Carbon steel weld consumables with nickel restriction less than 1%

[0707]

We have an iso pentane sphere with design temperature of (0ºC to 50ºC) Material is type A516 Gr 70 and pressure 1.5Kg/cm2. Should carbon steel weld consumables electrodes for welding this sphere plates have a nickel restriction less than 1%?

An answer should be appreciated

Luis Marques

 

[ijzer]

Resriction of max. 1% Nickel is applicable if spehre is subject to Sour service , see NACE MR0175 (now ISO 15156).
Check application with client.

 

[0707]

Tank you Ijzer, for your empathy.

The isopropane sphere is not subjected to sour service but it can eventually be contaminated with p.p.m`s of H2S. In this case in your opinion shall we be mandatory in this requirement of 1% nickel restriction?

Best Regards

Luis Marques

 

[metengr]

The reason for the 1% Ni limit is because of concerns by NACE toward increased susceptibility of sulfide stress cracking (SSC) in carbon and low alloy steel weld consumables and base metals exposed to sour service, as stated in NACE Standard MR0175.

From what I have read, the 1% Ni limit is still a subject of debate within NACE. If you would like more information on this subject, there was an interesting paper published by NACE in 2004, #04649 titled "An Overview of NACE International Standard MR0103 and Comparison with MR0175. The paper compared Standard MR0175 with MR0103, with the discussion about the limit of 1% Ni.

As ijzer mentioned, check with the client. In my opinion, the 1% Ni limit is not required for this application.

 

[stanweld]

It is doubtful that the service condition as described can be considered Sour Service. One question though, why would you use nickel containing filler metal? Standard carbon steel filler metals like E7018, F72-EM12K, E71T-1, ER70S-2,-3,-6 will provide adequate toughness for your design.

 

[0707]

Tank you all Ijzer, Metengr and Stanweld, for your replays.

I agree with you and I think that E7018-1 or E7018-G with a Ni % less than 1% will meet our purposes. The use of an electrode such as E8018-C1 is not ad equated to our needs.

Regards

Luis Marques