welding of carbon steel to low alloy steels

[pradeep4u]

Dear All,
I want to know that which filler wire to use when we weld carbon steel to p11 and carbon steel to p22.
Regards
Pradeep

 

[mk3223]

E7018 is suitable for the welding of CS to low Cr-Mo material.

 

[weldstan]

If weld is subject to PWHT requirements of the higher alloy, I recommmend using a filler metal matching the P11 chemistry for both joints. You could also use E7018-A1 for the CS to P11 and E9018-B3 for the CS to P22 weld.

 

[pradeep4u]

@weldstan and mk3223
Sir, if we use 7018 for welding carbon steel to p11 and p22, then tensile strengh of carbon steel and p11,p22 are different. Will it not affect welding joint quality. Is there any code which tells which filler wire for dissimilar metals and WPS of welding
Regards
A.Pradeep

 

[weldstan]

There is no code. The filler metal can match the high alloy side of the joint, the lower alloy side of thee joint or an intermediate alloy as I previously indicated, as long as the filler metal can meet the mechanical properties and service requirements of the weldment.

 

[mk3223]

Hope the link of the welding electrodes selection chart may help for you....

https://www.materialwelding.com/welding-electrode-filler-wire-filler-metal-selection-chart/

 

[david339933]

Section IX allows a WPS qualified on p11 and p22 materials to themselves to be welded to CS materials as well without re-qualification.
P5A - P5A qualifies P5A to P5A, P4, P3, P1.
P4 - P4 qualifies P4 to P4, P3, P1.

 

[pradeep4u]

Dear all
Thanks for your precious information. I will be grateful for that. I have one more doubt that why we use 8018 for p11 and likewise 9018 for p22 because 80 and 90 in code is tensile strength and not base material composition also tensile strength of p11 and p22 material s 60 psi. Please clear my doubts
Regards
A.Pradeep

 

[weldstan]

But 8018-B2 and 9018-B3 have both chemistry and strength requirements. The tensile properties are simply due to their chemistries.

 

[Dhurjati Sen]

Dear Pradeep,

A golden saying goes like this:

In case of different metallurgy, weld with the lower one and PWHT as per the higher material.



DHURJATI SEN
Kolkata, India

 

[pradeep4u]

Dear Weldstan and Dhurjati sir,
7018-B2 also has same chemical compostion as 8018-B2 only difference is tensile strenght of welding rod. While 70 ksi is tensile strenght of 7018 and 80 ksi is of 8018. Then how tensile strength different for same chemical compostion. Please enlighten me
Regards
A.Pradeep