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.
> 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
Nickel and cobalt don't seem prohibitively expensive for cutlery, around $15,000 [0] per ton and $33,000 [1] per ton respectively. By comparison, chromium is around $10,000 and iron is essentially free.
Even if the optimal ratio is 100% cobalt, that might add $1.50 to the price of a dinner fork or $50 to a cutlery set that will last a lifetime.
Walmart might not stock it, but that seems completely within the range of what you could charge for a premium product, if the nickel-cobalt-chromium alloys really do make for superior cutlery. Maybe it's less suitable for other reasons than cost.
[0] https://tradingeconomics.com/commodity/nickel
[1] https://tradingeconomics.com/commodity/cobalt
> 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. Pure chromium (without the iron) is not needed for production of stainless steel.
> Chromium is produced
Brearley steel debuted in 1915. The question is not how it is produced in 2025 but how it was produced in 1915.
Wikipedia partly agrees with GP:
“Also in the late 1890s, German chemist Hans Goldschmidt developed an aluminothermic (thermite) process for producing carbon-free chromium.[29] Between 1904 and 1911, several researchers, particularly Leon Guillet of France, prepared alloys that would later be considered stainless steel.[29][30]”
Though it points out a host of household names that knew of iron chrome alloys, including Faraday and Bunsen. Chrome steel existed for 75 years before Brearley came along but seems to have been used for things like canons, which are a lot more dear than cutlery. I wonder how they got their chrome 50 years before Goldschmidt.
Ferrochrome was first produced in electric arc furnaces in 1893, two decades before stainless steel.
The first ferrochrome produced thus had very high carbon content.
The only kind of stainless steel that could have had any chances of being made with such a ferrochrome would have been a martensitic stainless steel for knife blades.
In any case that kind of ferrochrome was not suitable for researching the properties of chromium alloys. The acceptable compositions for alloys like stellite or various kinds of stainless steels have all been discovered, after many experiments, only by using relatively pure aluminothermic chromium, which was a strictly necessary ingredient for enabling chromium alloy research.
Only after the required composition of a kind of stainless steel was understood and only if it was determined that such a composition can be reached by mixing ferrochrome with iron, the manufacturing process was adjusted for using cheaper ferrochrome instead of pure chromium.
Today there exists low-carbon ferrochrome, which is suitable for making most kinds of stainless steels, but even now the low-carbon ferrochrome is much more expensive than the high-carbon ferrochrome from which only martensitic stainless steel can be made.
Chromite was mined in the US back in 1811.
Ferrochrome is used to make Chrome steel and later stainless steel, but Chrome steel is significantly older.
The kinds of chrome steel used in the 19th century were very fragile, due to high content of carbon and of other impurities.
Their possible uses were very limited in comparison with the ductile stainless steels discovered in the 20th century.
Also the chemical resistance of the first chrome steels was modest, because it was not known which is the minimum content of chromium for avoiding rusting and also their composition was not well controlled.
Chromite was being mined then for use in chemicals, particularly for tanning, IIRC.