Need input on stainless

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My question is twofold. Or would it be my questions are twofold?Anyway first I need to know what I will need to do to meet the requirements of the project. Second is what can I do above and beyond that to improve my skills with stainless.This is one of my first times welding stainless to stainless with stainless filler so any input is much appreciated.Ok so the project requirements. The part is going to be used in a press as a form or mold of sorts.The thinner base plate (About 40-60 thou) is what the part will be resting on. The thicker plate on top (about 100 thou) is basically a shim/dam to keep the part from flowing where we don't want it and to keep the press from compressing the part to far. These are all samples I was playing with not the actual part however the actual part will be very similar to the large plate.The greatest stress will be compressive so it shouldn't have to be terribly strong. The only other strain I can imagine is from thermal expansion but I am hoping since it's all stainless strain should not be great.It will get up to probably 200-300C.Now I know you want minamal discoloration but I would also want to bust this out pretty quickly.The large plate I had to do short bursts of about 1/2"-5/8" and then move to a new spotI also had a large block of aluminum clamping it down so it acted as a heat sink as well as kept better contact on the welding table cooling the bottom. I did two edges fused and two with filler.This one I think I did in two longer runs without the aluminum block.It is a lot darker but I was able to do it much quicker. I am wondering if this is acceptable for this application.Here are some other small test pieces. Just tell me what areas look acceptable and what doesn't.Ok next question.If I can fuse this it would go much quicker and easier but I don't want it to fail.Would it be pretty safe to fuse it or should I use filler?Lincoln precision TIG 275Millermatic 140 MIG
Reply:"Just tell me what areas look acceptable and what doesn't."1-If this mold construction needs to be flat (and presumably it does),that should be your first concern--not the cosmetics of the test welds.If a full weld joint's required around the entire top piece--distortionof the base plate is your largest problem.2-What degree of flatness on the base plate and top plate, measuringin any direction is required?3-Using a base plate, significantly thicker than the top plate would help in any case.-adding stiffeners to the rear of the base plate, ditto-ditto for small plug welds on the top plate to keep it's central section, tightto the base plate4-Using filler rod, helps minimize distortion. Fusion welding as you've done creates big time distortion.-ditto for pulsing-ditto for laying the rod on the joint-firing off on the rod itself-not the work, to get fusion-ditto for lots of tacks, short welds,and considering water spray cooling with air blow-off during the welding.5-And if any or all of the above is too much hassle, then maybe considermechanically joining the 2 plates, ala countersunk flat head solid rivets (notpop rivets), or screws, or ???     Using fasteners to hold the top to the bottom as temporaries would help.6-the heat transfer in SS is very poor compared to steel or aluminum, whichmeans the heat doesn't spread out from the weld area nearly as fast and thusdoes a real number on creating distortionBlackbird
Reply:If it were me....I'd plug weld everything and leave the edges alone.  They'll stay nice and crisp and straight that way.  You did say this was for stamping right?My name's not Jim....
Reply:Thanks fot the input guys. Flatness is unimportant since the press will take care of small amounts of distortion as long as the thickness is the same. Clamping a flat block on top of the plate seemed to keep warping to a min and kept both plates in solid contact with each other.Plug welds allows resin to seep under the plate and creates a total clusterfarkwhen trying to remove the part. I'ts a long story on the process but this is basically a preforming. It doesn't need to be perfect just get us close for the final forming.Lincoln precision TIG 275Millermatic 140 MIG