While the invention of stainless steel is one of the most important in history, it should be noted that almost never an invention appears really independently, but almost always it appears as a consequence of a chain of prior inventions, which have been necessary to make it possible.
Leading to stainless steel, a first step was the discovery of the method to produce aluminum cheaply, by electrolysis. With cheap aluminum available, a method for producing chromium was discovered, by reducing chromium compounds with metallic aluminum.
With metallic chromium easily available, after a century from its discovery, during which making metallic chromium had been impossible in great quantities, it has become possible to investigate the properties of the chromium alloys with the other available metals.
Soon, it has been discovered that chromium can produce interesting alloys with cobalt ("stellite") and with nickel, and that these alloys are the first metals that can rival the platinum-group metals in chemical resistance.
It has been suggested that these chromium alloys could be used for stainless cutlery, but the high prices of cobalt and nickel have prevented the use of such alloys, except for special applications where the cost was unimportant.
More than a decade later, the next logical step has been the discovery that the expensive cobalt and nickel can be substituted with cheap iron, without diminishing much the chemical resistance of the alloys.
It should also be noted that while Brearley has invented the ferritic stainless steel, which has only small amounts of any other elements besides iron and chromium, almost simultaneously a different kind of stainless steel has been invented in Germany, austenitic stainless steel, which also has significant amounts of nickel, besides iron and chromium, with enough nickel to change the crystal structure of the steel.
Austenitic stainless steels have various advantages, especially that they are much more suitable to cheap processing by plastic deformation, so nowadays they are much more widely used than the kind of stainless steel invented by Brearley.
pfdietz · 51s ago
> Leading to stainless steel, a first step was the discovery of the method to produce aluminum cheaply, by electrolysis. With cheap aluminum available, a method for producing chromium was discovered, by reducing chromium compounds with metallic aluminum.
Are you sure about that? Chromium is produced (as ferrochrome, a FeCr alloy) by carbothermic reduction of chromite. This is done in an arc furnace, so electrical energy is needed, but no aluminum.
perihelions · 1h ago
> "algebra (Taylor bought him the book, a gift Harry brought home to show off, and never forgot)"
If anyone was hooked by this tangent, this was[0] "Todhunter’s[1] Algebra" [2] (1858? 1870? 1871? 1889?) you can peruse for free at [2].
> The range of the mind’s eye is restricted by the skill of the hand. The castles in the air must conform to the possibilities of material things—border-line possibilities perhaps; or, if something beyond the known border is required, the plan must wait until other dreams come true.
Leading to stainless steel, a first step was the discovery of the method to produce aluminum cheaply, by electrolysis. With cheap aluminum available, a method for producing chromium was discovered, by reducing chromium compounds with metallic aluminum.
With metallic chromium easily available, after a century from its discovery, during which making metallic chromium had been impossible in great quantities, it has become possible to investigate the properties of the chromium alloys with the other available metals.
Soon, it has been discovered that chromium can produce interesting alloys with cobalt ("stellite") and with nickel, and that these alloys are the first metals that can rival the platinum-group metals in chemical resistance.
It has been suggested that these chromium alloys could be used for stainless cutlery, but the high prices of cobalt and nickel have prevented the use of such alloys, except for special applications where the cost was unimportant.
More than a decade later, the next logical step has been the discovery that the expensive cobalt and nickel can be substituted with cheap iron, without diminishing much the chemical resistance of the alloys.
It should also be noted that while Brearley has invented the ferritic stainless steel, which has only small amounts of any other elements besides iron and chromium, almost simultaneously a different kind of stainless steel has been invented in Germany, austenitic stainless steel, which also has significant amounts of nickel, besides iron and chromium, with enough nickel to change the crystal structure of the steel.
Austenitic stainless steels have various advantages, especially that they are much more suitable to cheap processing by plastic deformation, so nowadays they are much more widely used than the kind of stainless steel invented by Brearley.
Are you sure about that? Chromium is produced (as ferrochrome, a FeCr alloy) by carbothermic reduction of chromite. This is done in an arc furnace, so electrical energy is needed, but no aluminum.
If anyone was hooked by this tangent, this was[0] "Todhunter’s[1] Algebra" [2] (1858? 1870? 1871? 1889?) you can peruse for free at [2].
[0] https://www.readingsheffield.co.uk/harry-brearleys-reading-j...
[1] https://en.wikipedia.org/wiki/Isaac_Todhunter
[2] https://archive.org/details/algebraforuseofc00todhuoft
That's a quote that surely appeals to many here.