E80 & E90 Classification Electrode usage

[hetpatel1104]

Dear Experts,

We have some WPS-PQRs for Above Ground Storage Tanks which were performed with SMAW process using E80xx (80 ksi) Electrodes for without PWHT and with E90xx (90 ksi)Electrodes with PWHT for the materials having tensile strength below 550 MPa. As per

API-650, clause 4.8,

SMAW electrodes classification E60xx & E70xx shall be used for the materials with tensile strength < 550 MPa and E80xx shall be used for the materials with tensile strength > 550 MPa.

Kindly suggest how can we propose the use of our existing WPS-PQR for the welding of A106 Gr.B with A105 materials with and without PWHT ?

Thanks and Regards,
Patel

 

[metengr]

For SA 106 Gr B and SA 105 base materials you have a WPS qualified with E7018 filler metal with and without PWHT.

 

[hetpatel1104]

Thank Mr. Metengr,

It is known that we have to use E70xx electrodes but my question is if we want to use already qualified PQRs with welding consumables E80 & E90 classification, what are the possibilities? What Technical supports shall we provide ?

Any suggestion from anybody for using welding consumables of Higher strength than Base metal ? How much difference in tensile strength can be acceptable ?

 

[metengr]

Well, you follow the applicable code of construction or standard. If the use of a particular strength filler metal is not mentioned or specified, you can use an overmatched strength filler metal provided you understand that higher strength could result in environmental cracking concerns.

 

[weldstan]

A change in A-No. may be an essential variable. A1 to A2 and vice versa is not an essential variable.

 

[hetpatel1104]

Thanks for the info !!

 

[Guest102023]

Don't go there. Weld it with E70 class filler.

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"