From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
The oxidation and acid resistance properties of NICHROMIC alloy.
| Identifier | WestWitteringFiles\V\December1930-February1931\ Scan063 | |
| Date | 23th December 1930 guessed | |
| - 2 - (b) - Resistance to oxidation.- This property is manifest not only when the alloy is in a hot state, but also in presence of acids. Articles made of NICHROMIC may be successively heated and cooled for over 2,500 hours before becoming unfit for use; this proves how little they oxidise under these conditions, which remarkable property causes them to be in demand for all applications of thermal treatment. Its resistance to acids is likewise exceptional, particularly to sulphuric-acid, even boiling, thus enabling pickling, macrographic etchings, etc..... to be done in throughs made of NICHROMIC. Thus, after forty-eight hours immersion in pure sulphuric-acid, an article made of NICHROMIC only loses .001% of its weight and, in acid at 10°B. (Baume) this loss only amounts of .0005%. After being subjected to the action of pure boiling sulphuric acid for four hours and in diluted acid for 10°B. a piece of this alloy only lost .013% of its weight in either case. In nitric acid at 10°B., the loss amounts to .003%. CONCLUSION. All these properties - which are constantly ensured thanks to the care and precautions taken in the preparation of NICHROMIC - make this alloy a first-class product, applicable to uses of the most varied description and the success of which is becoming more pronounced daily; our constantly-increasing production is the best guarantee of the full satisfaction which it gives to our clients. "NICHROMIC" is a high priced alloy but, in reality its qualities, its durability, make it a cheap and very economical product for those who use it. | ||