Switching from carbon to stainless

Q:We have been manufacturing carbon steel forgings for years and recently started manufacturing 304/304L/316/316L stainless steel forgings but we have cracking problems with stainless. Do you have guidelines for forging stainless steel?

H. James Henning

Aug. 26, 2006

A: The transition from carbon to stainless steel can be a problem because the forging loads for the 300 series grades are 3-4 times greater than for carbon steels. This will cause die fracturing and underfilling if the dies are not re-designed for stainless. There a many details that need attention. I can give some basic guidelines but I suggest that you send me photos or drawings of the intended parts, along with images of the dies you intend to use. I can comment more specifically with that information.

For more than 40 years H. James Henning held key technical positions in the forging industry, including as director of technology for the Forging Industry Association, and as president of Henning Education Services, a Columbus, OH, firm specializing in customized education and training in forging technologies.

Guidelines and recommendations offered in this column are based on information believed to be reliable and are supplied in good faith but without guarantee. Operational conditions that exist in individual plants and facilities vary widely. Users of this information should adapt it, and always exercise independent discretion in establishing plant or facility operating practice.

About the Author

H. James Henning

In all, Jim spent 44 years as a technician, engineer, and supervisor in the forging industry prior to his retirement, including nine years as technical director of the Forging Industry Assn.

Upon his retirement from FIA in 1996, Jim formed Henning Educational Services Inc. There, he filled a problem-solving role for forgers and other manufacturers seeking solutions to process and organizational issues. He shared his expertise on hot, cold, and warm forging, on tool design principles, process and equipment selection, and productivity and quality improvements.