First let me say that any welding done on rotating equipment be done using welders and procedures qualified in accordance with the requirements of the applicable code of construction (AWS D14.6 If I recall correctly)

When qualifying a procedure you may want to keep the following in mind.

Regular ER 70 XX wire will work for AR(Abrasion Resistant) 200 plate however the weld will not have the abrasion resistance as the base metal. "AR" plate can have many different compositions and the mfg is usually the best source for information.

AR plate that is basically High Strenth Low Alloy steel that is Quenched to acheive hardness and maybe is tempered a little. Because of this the material properties can be changed if welding conditions change.

Groove joints should allow for complete penetration.

Joints that do not have 100% penetration should be fit in a manner that does not allow the the joint "jam together" before the weld is complete. An example would be welding a fan blade or blade wear pad to a fan hub with a fillet weld and placing "crush wires" in the joint. 1/4" probably wouldn't be a problem but if cracking occurs this can help.

Preheat helps reduce the cracking usually but excess preheat and/or heat input can remove the "AR" from the area near the weld.

Try not to let your welds stop craters stop at the end of a joint especially at the junction of the impeller shroud and the blade.

If preheating thick sections allow for enough time for the section to be heated through.

Highly restrained joints are more likely to crack.

I hope this will help you get on the right track. There may be some Eng/Metallurgy types on the forum that can offer some more information or maybe some good sources of information.

I wish you well.


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