PROPORTION OF TENACITY OF SINGLE LINKS TO
TENACITY OF BARS.

1급 11%
11월 11층
1 1 1 1 1 1 172 17 2

AVER

AGES.

Table III. Relative Values of Irons in Bars in tenacity, red. of area and elon., and in Proportion of Chain to Bar.

Table IV. Relative Values of Irons. Average for Bars, Short Chains,

Table II. Abstracts of physical tests of irons, and proportions of strength of links to that of bars.

Table III. Relative values of irons in bars, in tenacity, reduction of area, and elongation, and in proportion of chain to bar.

Table IV.

Relative values of irons. Average for bars, short chains, and single links.

Table V. Showing effects of variation of reduction and of uniformity of reduction on strength.

* Iron L, bars of which exceeded all others in tenacity, when tested in single links only, gave the lowest welding value.

In the Report of the Board, under the head of Phosphorus, the leading chemical and physical facts about each iron likely to be affected by this element are compared, and then the group of irons is considered, and a conclusion is reached; under the head of Silicon the irons are again gone over in a similar manner, and so on with Carbon and other ingredients. A description of a few irons in which composition should have the greatest influence on strength will suffice to introduce these conclusions.*

Effects of Phosphorus.

Iron O. P., 0.07, Si., 0.07, C., 0.04. Slag medium.
Chemical impurities all very low.

The iron had been thoroughly worked.

Tenacity as bar and as link very low.
Ductility as bar and as link very high.
Welds very good.

Low phosphorus does not alone account for these qualities. Iron F with P., 0.20, Si., 0.16, and-C., 0.03, has about the same tenacity and welding power, and approaches the same ductility. Iron P with P., 0.17, Si., 0.10, and C., 0.05, has about equal ductility. Seeing that the thorough working of the small bars decreased welding power, as compared with that of the less compressed large bars, it is probable that method of manufacture is an important factor in all physical results. The effects of low phosphorus are not conspicuous.

Iron P., P., 0.17, Si., 0.10, C., 0.05. Slag very low.
P., and C., medium; other impurities rather low.

Tenacity high as link and as bar.

Ductility high as link and as bar.
Welding power medium.

Iron properly worked for tenacity and durability, but overworked for welding. (See iron Px.)

This iron had the highest average of good qualities, and was the best for general constructive purposes. The characteristic effects of phosphorus are shown by the behavior of two specimens of iron P, viz.:

1 in. bar, P., 0.25, had tenacity 58,000 lbs., and elongation 14 per cent.

*It is hoped that those who are interested in this subject will analyze these data, and point out new readings and missing links in the evidence, if such there may be.

1 in. bar, P., 0.09, had tenacity 53,000 lbs., and elongation 24 per cent.

But this increased tenacity and decreased ductility of the 1 in. bar are not due to P. alone; it had Si. 0.18 against Si. 0.03 in the larger bar, and it had more reduction in rolling. Phosphorus 0.17 may thus accompany the highest general value; that this element did not cause inferior welding, may be inferred from the fact that iron Px, made of the same materials and in the same way, except that one course of piling and hammering was omitted, welded much better, although its tenacity and ductility were decreased.

Iron D, P., 0.18 (0.12 to 0.24); Si., 0.15; C., 0.03; slag low.
Carbon low; other impurities medium.

Different bars very differently worked.
Tenacity high as bar and link.

Ductility below medium as bar and link.

Welds very good.

There are various proofs that low phosphorus, even with low silicon, do not make high ductility, and that the amount of reduction is the more important factor. For instance:

1 in. bar, P., 0.24, Si., 0.17, has tenacity 61,000 lbs. ; elongation, 26 per cent. 1 in. bar, P., 0.16, Si., 0.11, has tenacity 56,000 lbs.; elongation, 23 per cent. 2 in. bar, P., 0.19, Si., 0.18, has tenacity 51,000 lbs.; elongation, 18 per cent.

The welds of the medium-sized and worked bars were best, but all were good. No harmful effect of phosphorus can be traced in this iron.

Iron B welded best, and had P., 0.23, and C., 0.015.
Iron F. P., 0.20; Si., 0.16; C., 0.03; slag low.

Carbon low; other impurities medium.

Iron suitably worked for welding, and very uniform.

Tenacity as bar and as link very low.

Ductility high.

Welding power good.

The remarkable uniformity of this iron proves it to have been made with great care from selected materials. Why its tenacity is so low it is difficult to say on chemical grounds. The same iron, Fx, more worked, gives a medium tenacity, with substantially the same analysis. Iron A, with less P., Si., and C., is stronger. Iron E has lower P., the same Si., and only 0.02 C., and yet a higher tenacity.