17-4PH question

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Hey All,Anyone have any experience tig welding 17-4? I need to make some 3/8" dia x 36" L drag bars out of it so it can be easily hardened. I'd like to stay with 304 chain attachment clips to keep cost down on laser cut parts. Any thoughts?Thanks
Reply:The 304 can readily be welded to the 17-4 with 308 filler metal. The issues are: What is the state of the 17-4? Is it annealed, double annealed or normalized? What is 17-4 current hardness and how hard will it be after?
Reply:ER308 or ER309 are listed as the generally suitable fillers for welding 17-4PH stainless steel.  The best laid schemes ... Gang oft agley ...
Reply:It will be annealed and should be somewhere around 35 RHC. This may actually be sufficiently harder compared to the 304 bars I'm looking to replace as they would probably be 90-94 RHBThe most I can get is 44 RHC with precip. hardening at about 490 C for 1 hr.I was thinking about  trying to zone harden the middle 2' of the rods to eliminate flex but avoid potential stress cracking at the connection points...Thanks for the reply
Reply:Ummm, dude, you seem a bit confused about some stuff.All steel "flexes" the same.  Plain 1020, 4130 chro-moly, D2 tool steel at Rc-60, whatever.  Hard steel, soft steel, high $$$ tool steel, if it's made of steel, the Modulus of Elasticity is approximately 29-30E6 psi.One difference between the various steels would be that a soft/weak steel may start to permanently deform (yield) at a certain load/deflection, while a harder/stronger steel may spring back to the original location once the same load is removed.  But up until permanent deformation occured (yielding, plastic yielding, etc), all the steels will 'flex' the SAME.  (if all else physically is the same).To reduce flex/spring, you have to change the SECTION PROPERTIES.  The best laid schemes ... Gang oft agley ...