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).
Micro-examination and analytical report on samples of special welding wire.
| Identifier | ExFiles\Box 36\3\ scan 021 | |
| Date | 22th April 1926 | |
| COPY Micro-Examination and Analytical Report. M.471 RHC{R. H. Coverley - Production Engineer} C.BY. Hl1/EA22.4.26. Laboratory. Re Samples of Special Welding Wire. In the first place two samples of wire were submitted, one marked "A" and the other "B". Both were mild steel, the analyses being as follows:- "A" "B" Carbon--------------- 0.16% ......... 0.27% Manganese------------ 0.36% ......... 0.76% Sample "A" was plated with nickel. The coating of nickel was found to vary in thickness on a transversal section from 0.0006" to 0.0015". The contact between the nickel and the steel appeared to be fairly free from oxide, and there were only a few small seams. This sample, however, contained a considerable amount of slag inclusions at the centre, probably the tail end of a pipe in the ingot from which the wire was made. Two further samples of wire from the batch represented by sample "A" were also submitted. These were unmarked and whilst one contained nearly as much slag as the first sample, the other was fairly free from this defect. The nickel coat on each varied in thickness as in the first sample, the actual depth being:- 0.0008" to 0.0020" 0.0013" to 0.0030" The amount of nickel present on sample "A" is 1.8% of the total weight of the sample submitted. On the other samples the amount will probably be considerably greater. The carbon of sample "A" is more than we permit in our own specification No.204. The extra samples submitted were not analysed, but the carbon content appeared about the same under the microscope. We have no experience of electro-plated nickel wire for weldings but conclude that though the nickel may protect the wire to some extent from oxidation during fusion there would be a tendency to get local variations in the nickel content of the weld itself tending to produce hard spots and corrosion effects. Sample "B" was not plated but had a fairly good surface with only a few seams. The inclusions were negligible. Two further unmarked samples from this batch each contained a few rather large particles of slag. We consider the carbon and manganese content of sample "B" to be much too high and should expect unsatisfactory results from the use of such a wire. The extra samples of this wire were not analysed, but the carbon content appeared about the same under the microscope. Hl. | ||