Riza Posted July 9, 2015 Share Posted July 9, 2015 Dear Sirs,Greetings.I have a problem in thickness reduction of CK15 blades with dimensions of 10*70*2 mm. I want to create tensile residual stress in the surface of them; thus I have to reduce the 2mm thickness to 0.2 mm in one pass. But, due to leakage of equipment and budget, I cannot approach rolling machine, etc.Is there any simple and money-free way like hand hammer that I can reduce the 2mm thickness to 0.2 mm in one pass and create tensile residual stress in the surface of work piece.Kind regards,R. Farshbaf Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted July 9, 2015 Share Posted July 9, 2015 Hire it out. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted July 9, 2015 Share Posted July 9, 2015 (edited) Residual stresses indicate you are doing this cold and want a reduction from 2mm to .2mm (or was this by .2mm so the piece is 1.8 mm afterwards?)I don't know if you could go from 2mm to .2 mm cold in one pass without catastrophic failure even in a rolling mill I do note that Saaj steel says they they can provide "rolled material in any grade" and list CK15. I would want to test the resulting piece to be sure it had the properties needed! Edited July 9, 2015 by ThomasPowers Quote Link to comment Share on other sites More sharing options...
Riza Posted July 10, 2015 Author Share Posted July 10, 2015 Dear Sirs,I want to reduce the thickness of CK15 blades.I wonder if anyone suggest simple ways of cold thickness reduction.Thank you in advance.R Farshbaf Quote Link to comment Share on other sites More sharing options...
BIGGUNDOCTOR Posted July 10, 2015 Share Posted July 10, 2015 First , what is a CK15 blade?How thick, how hard?What shape?How much do you want to take off of them?If they are flat , a surface grinder will do it. Odd shaped, well that depends..... Quote Link to comment Share on other sites More sharing options...
Riza Posted July 10, 2015 Author Share Posted July 10, 2015 First , what is a CK15 blade?How thick, how hard?What shape?How much do you want to take off of them?If they are flat , a surface grinder will do it. Odd shaped, well that depends.....CK15 is a low carbon steel with dimensions of 10*75*2 mm. I want to reduce its thickness from 2 mm to 0.1 mm. I am searching for cold working processes.It is important to note that there is not any rolling machine around my area. Quote Link to comment Share on other sites More sharing options...
Charles R. Stevens Posted July 10, 2015 Share Posted July 10, 2015 Cold work realy only leaves stock removal, so grind, file, scrape.... Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted July 10, 2015 Share Posted July 10, 2015 (edited) Actually from his earlier post it should like he wants to end up with "cold rolled" as they want the work hardening "residual stresses"; but he doesn't have a rolling mill and he wanted the decrease in thickness to be around 90% 2mm to .2mm. I don't know if you can do that much reduction all cold without failure or ending up with a unusable piece.Really a question for a trained metallurgist with experience with this sort of alloyFrom wiki:Cold rolling cannot reduce the thickness of a workpiece as much as hot rolling in a single pass.Cold-rolled sheets and strips come in various conditions: full-hard, half-hard, quarter-hard, and skin-rolled. Full-hard rolling reduces the thickness by 50%, while the others involve less of a reduction. Skin-rolling, also known as a skin-pass, involves the least amount of reduction: 0.5-1%. It is used to produce a smooth surface, a uniform thickness, and reduce the yield point phenomenon (by preventing Lüders bands from forming in later processing). It locks dislocations at the surface and thereby reduces the possibility of formation of Lüders bands. To avoid the formation of Lüders bands it is necessary to create substantial density of unpinned dislocations in ferrite matrix. It is also used to break up the spangles in galvanized steel. Skin-rolled stock is usually used in subsequent cold-working processes where good ductility is required.Note that 50% reduction is considered about the maximum in a single pass. Edited July 10, 2015 by ThomasPowers Quote Link to comment Share on other sites More sharing options...
Charles R. Stevens Posted July 10, 2015 Share Posted July 10, 2015 Lots of hammering then. Good luck. Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted July 10, 2015 Share Posted July 10, 2015 I want to know why you felt a need to repeat the same exact question you posted yesterday? Quote Link to comment Share on other sites More sharing options...
Glenn Posted July 10, 2015 Share Posted July 10, 2015 I have combined all related posts into one thread. Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted July 10, 2015 Share Posted July 10, 2015 and they still dont make any sense Quote Link to comment Share on other sites More sharing options...
Frosty Posted July 10, 2015 Share Posted July 10, 2015 (edited) I think this is from another mid-east company, probably mid level management looking for who knows what. I'm thinking maybe a translation and misunderstood technology. For example, translate "Hydraulic ram" into Chinese and translate it back and you get "Water Sheep". Of course I'm just speculating but it sure reads like mid level management speccing out fab projects I had to unravel and build back when I was the fabricator on the drill crew. You have NO idea how tempted I was to follow directions literally when the Chief BRIDGE Engineer told me to just get some steel and weld it together. An ENGINEER! Go ahead wonder, I do .Anyway, that's how this OP strikes me but what do I know.Frosty The Lucky. Edited July 10, 2015 by Frosty Quote Link to comment Share on other sites More sharing options...
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