On Thu, Aug 17, 2023 at 01:26 PM, Tool247 wrote:
The work hardening issue is common among all austenitic stainless alloys all the way up to the high nickel super alloys like inconels and monels.
?
When Dad designed his experimental plant to determine the properties of steam at high temperature and pressure (800¡ãC, 1000 Bar - 1472¡ãF, 14500 psi) everything had to be made of Nimonic - primarily a nickel chrome alloy. (It's a descendant, via the early jet engines, of the nichrome wire used in electric fire elements.) The college got some bars and put them on the donkey saw to cut the end off one. At the end of the day they'd used up their stock of blades and were still only halfway through. He went to Wiggin Nickel, who put the bar up on what looked like a modern chop saw (this was 1950s). The blade was a disc of soft iron, but it went round very fast. It chopped off the bar, with a huge shower of sparks, and the disc was half the size. Chuck the remnants away, fit a new disc, and they were ready burn through the next cut.
One component needed a ?" diameter hole drilled 12" deep into solid Nimonic. He was very concerned about how to do it as any work hardening would scrap the whole job, but he discovered someone in Bristol had made something similar a few years before. He went down to Bristol to see what he could learn, and took a technician from the workshops with him. While Dad chatted about the rig design with the Bristol academic, the technician discussed machining techniques with the guy who had done the work. After that Dad was considered a VIP in the workshops. No academic had ever before (and maybe not since) thought to get his technician that involved in the project as to actually take him out as part of the team. He subsequently made many complex components in Nimonic, and (I've just checked) says in the Acknowledgements of his PhD thesis Dad says: "My thanks are due to Mr A. M. Alger, of the Imperial College Chemical Engineering Workshops, without whose skill the plant could not have been built"
It was typical of Dad that whilst being? leading academic in his field, constantly dealing with advanced maths and tricky statistics, he was very aware of the everyday practicalities and difficulties of simply making stuff - not always simply. I recall the name Alger coming up quite often during chats at home. Maybe this is part of the reason I always like to be in touch with the people who make the machinery I design, and to try to avoid difficulties at the design stage.
