|
Title: Runner materials Post by: wingnut 772 on May 13, 2007, 10:27:01 PM I was wondering if anyone is using precipitated stainless steel for runners. I read about it from Daan Schute's article about it.
John Title: Re: Runner materials Post by: Ken Smith on May 16, 2007, 06:31:26 AM Don't know where you read that article, but please share it...
Runners are often made of hardenable stainless, 440C being most common in the US. Specialty runners are also common in 316 and sometimes 304. These softer materials work well in snow and slush. Not to say these wouldn't be great, but it is hard to experiment with expensive components in the limited time we have to sail and when we have a good solution. Criteria for the perfect material: sharpenable, will easily polish, ductile (resists cracking), hard (resists wear, holds an edge), machineable, available, and steel alloy (not nickel or cobalt or titanium, DN rules), corrosion resistant, doesn't warp when heated, low friction on ice, cheap, available in many T-shapes, angles, plate and bar thicknesses to 0.27 inches Common solutions: Mild steel (cheapest), spring steel, tool steel (Sarns), austinitic stainless (316), martensitic stainless (440C) (Sherry product) See http://www.materialsengineer.com/E-Stainless-Steel.htm or http://www.alleghenytechnologies.com/ludlum/pages/products/xq/asp/G.11/qx/ProductLine.html or http://www.alleghenytechnologies.com/ludlum/pages/products/xq/asp/G.4/qx/ProductLine.html for some background on stainless. Title: Re: Runner materials Post by: wingnut 772 on February 03, 2008, 09:25:02 AM Ken I found a link to the link about the precipitated steel.
its on this website in its links section on the right . It stats with eissensomething bla bla bla http://home.maine.rr.com/iceboatmaine/index.html/Runner%20Talk.html John Title: Re: Runner materials Post by: daan h633 on February 07, 2008, 04:46:58 AM I have not seen any recent development in precipitation hardening stainless steels that would produce an alloy really suitable for iceboat runners.
The problem: All alloys that can be hardened sufficiently (AISI 632 seems suitable) contain elements that are really bad for polishability. This is particularly true for aluminum and titanium. So, we will have to wait for further developments in this industry. For now 304, 316 and 440C are best. Daan |