Welding 15-5PH or 17-4PH after heat treatment

Hello folks, anyone got any info/thoughts on welding either of these steels (as printed parts) in their post heat treated state onto Columbus XCR? Been scouring the net and getting fairly conflicting info, basically some say it’ll be absolutely fine with appropriate filler and other sources say it should only be done prior to heat treating with heat treating afterwards, which ain’t an option!

No direct experience doing it wrt bikes/3d printed parts, but generally if you weld a precipitation hardening metal without heat treating, you will lose joint strength. XCR is Martensitic, so it should in theory do the same thing as a PH steel in heat treating. Maybe it would be possible to do in a powder coating oven if that’s something you had access to?

If you can look up and compare tensile strengths of the part, the filler, the tube, you could estimate if even with the loss of overall strength it may still be fine for a bicycle application. XCR tensile strength is in the ~1200 range I’m pretty sure.

Or, do a few practice joints with different fillers and destruction test. Expensive, but it will give you the info you need!

Thanks for the input @Schonstudio ! In further investigation I don’t think the printed part in 15-5 will need heat treatment. I think this is a lazy old piece of knowledge that I had in my head that 15-5 and (17-4) would generally always be heat treated before their final application but I’ve since learned that’s incorrect and you can use it in its “straight from print” condition. It still has pretty high UTS and YS, listed as 1050 and 950MPa respectively. Its actually got very similar properties to Ti in the “as print” table from Ram3D

Not much experience in heat treating at all but all super interesting!

XCr has UTS of 1450 so it’s right up there! I’m thinking the use of 312 filler would be sufficient for bicycle joints and seems to be fairly widely recommended for welding 15-5 although I’m sure there may be a more suitable ones out there?

Thanks for your time, appreciate it!

Ram3D_Templates_MaterialProperties_v7.pdf (90.8 KB)

Like @Schonstudio said, welding will dissolve the precipitates in the HAZ of the 15-5 which negates the precipitation hardening. There’s nothing you can do to avoid dissolving them, so put the weld joint in a lower stress location. The XCr is made to be welded so it should be fine. 312 is the right filler metal. Keep both the heat input and interpass temperature low to minimize grain growth and you shouldn’t have any issues.

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Thanks @Jesse appreciate the input!

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