It had to give hardness results comparable to the sodium hydroxide solution, and it should be bio-degradable if possible. The result was that Robb and the Sandia Labs metallurgical lab crew went to work to find a replacement solution. Then OSHA arrived on the scene and insisted that the use of the sodium hydroxide solution cease. This stuff is pretty harsh and the need for a vented hood was a no-brainer. So, Robb started using this solution at Sandia Labs, but installed a vented hood system over the quench tank. Robb found that the sodium hydroxide quench resulted in average Rockwell ratings in the 43-45 range, with an occasional test result as high as 48. Generally speaking, in a plain water quench you shouldn't expect to get more than Rockwell ratings in the low to mid 30's. It may get a little harder than if annealed, however it doesn't harden in the typical toolmaker's sense of hardening. Metallurgists and others will tell you quite readily that mild steel won't harden. The manufacturers claimed that it was also suitable for many tools, but that it should be quenched in a solution of sodium hydroxide.Īt Sandia Labs, Robb and his cohorts experimented with this lye quench and, a bit to their surprise, they found that mild steel hardened considerably more that expected. Mild steel (1005, 1018, and the like) was touted as the all purpose steel destined to replace wrought iron. The Bessemer process gave the steel manufacturers the ability to produce steel in a variety of carbon levels. Here's what he had to say about it at the Guild of Metalsmiths 1997 Fall Conference:īefore the Bessemer process made it feasible to effectively control the amount of carbon in steel, blacksmiths generally had only iron or tool steel to work with. There is often a great deal of disbelief as to the efficacy of this Super Quench. Yes, there are some errors, but generally minor. Whether its on the internet group "theforge", at ABANA chapter conferences, or just general discussion between a couple of friendly smiths, when the subject of Robb Gunter's "Super Quench" comes up, most of it is fact, but some of what is passed around is erroneous. It will result in a spectacular visit from the TINK fairy.Ask me how I know. A bent spike will still hold a rail whereas a broken spike will not.ĭo not and I repeat do not use this stuff on anything higher than about. The reasoning is that the railroads want mild steel that will bend rather than break. Knife blade steels typically contain between 0.85% and 1.5% carbon, or 3-5 times as much carbon as a "High Carbon" railroad spike. According to the specifications, low carbon spikes may contain no more than 0.12% carbon and "High Carbon" spikes may contain NO MORE THAN 0.30% carbon. The problem is that what the railroads consider "High Carbon" is equivalent to what a knifemaker would call low carbon mild steel.Īccording to specifications set forth by American Railway Engineering Association there are two classes of railroad spikes, low carbon track spikes used on straight sections of railroads and high carbon steel track spikes used on curves and switches. One big misunderstanding comes from railroad spikes that are marked "HC" for "High Carbon". However, they simply do not contain enough carbon to make a good blade. Railroad spikes are readily available, usually for free, they are a novel item, and they can make a perfectly useable knife. Nearly every bladesmith has made knives from railroad spikes. Another "high carbon" misconception involves railroad spikes.
0 kommentar(er)
