Hi dears I have a question about cold forming of austenitic stainless steel. If A.S.S. be in solution annealed condition, how much cold forming maybe result outgo from this condition (because of generation low-carbon martensite due to cold forming)? best reagrd

Added to Mr.Srinivasan reply for Aus.SS hardness limitation is more than 200BHN. Regards,

Microeng It is true that 20% work hardening will give rise to martensite transformation (to some extent) in SS materials at RT. Hand books give general effect information for guidance purposes. From effect of SCC, you have to consider the specific corrodent (for example : chlorides, sulphides, alkali or other effect of contaminants in corroding medium, temperature, concentration, agitation, velocity, welding and residual stresses in HAZ or parent material etc and then consider the effect of cold working or hot working strain of --% strain on SS materials). With specific corrodent and the above likely factors taken into account one has to look the effect of --% of strain (whether cold worked or hot worked or welding and residual stresses due to welding) before raising a question or getting worried on a general assumption of --% strain would be harmful from effect of SCC in SS materials. Your apprehension on the effect of SCC on SS 304/316 with 10% work hardened strain and the question or doubt raised is too general to answer at this stage. In fact you will be surprised that residual tensile stresses due to welding in HAZ or parent material will be much higher in some cases (due to care in welding - weld design, welding inter pass and post care practices) may be as high as yield strength in some cases (compared to the 10% strain you are considering will harm SS) that even small quantity of chloride in ppm level will promote SCC at RT Hope this clarifies your point raised C.V.Srinivasan Nishi Engineers pvt ltd India Dec 24, 2008 E-mail: nishi@vsnl.com >From the data I have seen for 304 ss, at room temperature >you need to achieve about 20% true strain before martensite >transformation can be detected. This information is right >out of the "Handbook of Stainless Steels" by Peckner and >Bernstein. > >Now regarding useability, this is a different matter because >I would be more concerned with residual tensiel stress and >increased susceptibility to carbide precipitation and to >stress corrosion cracking with even 10% true strain, despite >no detectable martensite transformation product.