Electron Beam Weld Strength

[Mchel80]

Hi All,

I have two 1.8"OD Tube with a Wall of 1.4mm made of 17-4PH 105K Yield and I will be electron welding them together to a depth of 1mm. The Axial load of the 1.4mm tube is approx 345K lbf. I need to determine the axial strength of the 1mm weld sections. I could take the weld as the wall thickness and determine the tube strength, but due to the fusion welding i am not sure if the weld area is going to provide the same yield strength. Can you provide a suggestion for determining the weld strength.

MChel80

 

[Mchel80]

Sorry the Axial Load of the 1.4mm tube is 32K lbf

 

[desertfox]

Hi Mchel80

As far as I am aware assuming this is a butt weld I would say that the joint is 95% as good as the parent metal in terms of strength, however why aren't you making the joint with a full penetration weld?

http://books.google.co.uk/books?id=OrlG98AHdoAC&pg=PA390&lpg=PA390&dq=electron+beam+weld+st

rengths&source=bl&ots=hsULZHBexo&sig=X7afG4vnimxwgZe68wXd
cT8OcBw&hl=en&ei=MptrTZ-PB4qWOvD4naIL&sa=X&oi=book_result&ct=result&resnum=3&ved=
0CDAQ6AEwAjgK#v=onepage&q=electron%20beam%20weld%20strengths&f=false

desertfox

 

[metengr]

Is there any reason why you did not make a full penetration weld for this design? The problem as I see it is you have a weld with incomplete penetration - 1mm penetration versus 1.4mm. This implies you have a notch at the root of the weld and this could be a problem under cyclic load service.

Second suggestion - instead of using calculations, I would run a test coupon simulating your weld joint configuration and qualify the electron beam weld procedure using tensile and bend testing (following ASME B&PV Code, Section IX Guidelines). Nothing better than having a production weld coupon that provides actual location of failure, and ductility of the weld joint.

Third suggestion - Regarding strength of the weld joint, as part of the qualification of the electron beam weld procedure, I would have a cross section of the weld region prepared for metallographic examination with microhardness testing. This will give you some idea as to the strength of the weld region.

 

[Mchel80]

I cannot have a penetration weld as the inside face nees to be flush and a penetration weld will have a notch on the ID. I am performing a hardness test on the weld after sectioning it. I am also conducting a tensile load test to 32K lbf. I will refer to the asme code for qualifying the weld.

MChel80

 

[blacksmith37]

The HAZ and filler (assume matching filler) will be mostly solution annealed. In this condition 17-4 can be expected to have poor toughness and ductility; I would reccommend 1150F for an hour as an age (if service is critical).

 

[TVP]

MChel80,

Is there a reason why you cannot have a complete penetration weld and then finish the ID by turning, skiving, burnishing, etc.?

 

[Mchel80]

TVP,

I cannot have a complete penetration weld as the internals will be pre-honed before welding and cannot be accessed with general manufacturing practises,

 

[EdStainless]

Sounds like you need a special weld geometry. Maybe fit them together with a step, and weld clear down to the base of the step.
You will need to age after welding to achieve any reliable properties.

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