Cylinder welding

Date 09-19-2000 21:15

I am currently trying to weld a hydraulic cylinder with a 1045 cap to a 1026 barrel. We are currently using a flame preheat to provide the preheat we need in order to obtain the penetration and profile that we need. We are trying to get away from preheating since it takes a lot of extra time and labor to do so. When preheat is not used we get a narrow penetration profile and the weld fails prematurely in our fatigue testing. We are using straight C02 root pass and it is a u-groove joint approximately 13mm thick. 3 passes in all are being used when welding this joint. Any ideas on how this weld could be improved, would be greatly appreciated.

By dong won oh (*)

Date 09-20-2000 06:26

You look like to use turning rolls for welding.
I am using V groove for 13mm thick with FCAW with mixed gas for piping shop.
For your situation, I would like to recommend as follows:
1) use V groove with 50-60 degree to get better penetration
=== you need more time for welding but less time for edge preparation and possibly no preheating
2) you need 4-6 passes
3) for cap passes, use relatively high voltage to get small toe angle
4) consider weaving unit for better penetration and bead shape