Are there a short-term (during processing, 4-24 hours) and long-term (7 days - 2 years) concerns about mixing 316L stainless parts with Hastelloy grade parts in terms of corrosions? These parts are used during the GMP production of pharmaceutical products and will be product contacting.
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Brian Dalder Forum Moderator 177 Posts
Re: Are there concerns with mixing 316L stainless steel with Hastelloy grade parts?16 May 2012 at 1:29pmThe degree of concern depends on how corrosive the streams are to the 316L stainless steel. As you undoubtedly are aware, 316L stainless steel is less corrosion resistant than the Hastelloy C alloys (assuming you are talking about the Hastelloy C family!). So, if corrosion occurs it will happen with the 316L stainless steel first. In addition, you have the possibility of enhancing the corrosion of the stainless steel through galvanic coupling with the Hastelloy. 316L stainless steel is anodic to the Hastelloy C alloys and small stainless steel parts coupled to large Hastelloy C pieces could cause the stainless steel to corrode very fast. Due to supply issues, we have faced similar situations at my company regarding the mixing of austenitic stainless steel parts with those made of Hastelloy C alloys and I generally do not recommend this. It has been my experience that even if there are no compatibility issues with the original process, issues often crop up later with new processes as people lose track of what mixture of materials they have installed on a particular set of equipment.