T echnical and econom ical conditions of the h eavy m etallu rgical in d u stry of th e east of France,
w ith particular reference to the u tilisa tio n of ga ses and m otive pow er. J. Se ig l e (Iron and Steel Inst., May, 1927. Advance copy, 72 pp.).—The available ore is phosphoric, and the gangue either siliceous or calcareous ; thus a t many of the blast-furnaces the two types of ore can be mixed, so obviating the necessity of adding lime
stone. The ores are sent raw to the blast-furnaces. The bulk of the pig iron produced is made into either basic Bessemer or open-hearth steel, or used for castings.
During the war, in order to increase the production of pig iron, steel turnings and scrap were put through the blast
furnaces ; the steel thus becomes carburised during its descent through the furnace with the coke, and cast iron is produced. By this means the output of the furnace can be increased by 50% and the consumption of coke is decreased. The basic pig iron so formed is deficient in phosphorus, and this is compensated for by the addition of basic slag. The existence of fundamental relationships between the proportions of the constituents of the th ro at gases, carbon monoxide and dioxide, and the volumes of the blast and of the gas produced is demonstrated. Methods in actual use for improving the efficiency of the Cowper stove, for heating the various types of furnace, and for employing surplus blast-furnace gases are described. The means employed for power gen
eration are described, and the efficiency of gas engines is discussed. I t is shown th a t the theoretical consumption of steam per effective H.P. is much improved when tbe pressure is increased, and technical advances which take advantage of this are indicated. The steam is now superheated a t 350—375°, and the effective steam- pressure on the turbines has steadily increased to 35 atm.
The feed-water and the air for combustion of the blast
furnace gases are also heated, and various devices are employed to ensure an intim ate and rapid mixture of the air with the gas for combustion. The basic process gives naturally a steel low in carbon ; the addition of 0 • 6%
of ferromanganese gives a steel with a tensile strength of 26 tons/sq. in. If extra soft steel is required, the after
blow is increased, and rather less ferromanganese added.
For semi-hard or hard steels, recarburisation is adopted.
The resistance of rails to wear is increased without introducing fragility, either by cooling the head of the rail by jets of air and water spray (Sandberg process), or by interm ittently quenching it in a predetermined amount of cold water. A two-stage process for the manufacture of hæmatite pig iron from phosphoric pig iron is referred to in which the phosphoric pig iron is first dephosphorised in a converter, which results in a partial décarburisation, and then recarburised to the desired carbon content. Details of the dry-quenching of coke by the Sulzer process are given. M. E. Notta ge.
Interactions of g a ses and ore in the blast-furnace-I. A t tem peratures up to 650°. W. A. Bone. L. Re e v e, and H. L. Saun ders (Iron and Steel Inst-.:
May, 1927. Advance copy, 41 pp.).—The interaction of bæm atite ore and gases approximating in constitution to blast-furnace gas has been studied a t varying tem pera
tures between 380° and 650° by the “ circulation method”
introduced by Bone and Wheeler (Trans. Chem. Soc., 1903,83,1074—1087). At all temperatures used, nearly all the carbonic oxide in the dry system was used up in ore reduction up to about 10% deoxidation, a t which
B r itis h C h e m ic a l A b s tr a c ts —B .
C l. X .— Me t a l s ; Me t a l l u r g y, i n c l u d i n g El e c t r o- Me t a l l u r g i y. 4 8 5
point ore reduction was decelerated and carbon was deposited. At the highest temperature (650°) no carbon deposition supervened until 90% ore reduction had been effected. The introduction of 2% of hydrogen to the gases materially increased the proportion of carbon monoxide used in reducing ore and diminished the carbon deposition a t 550°. C. A. Kin g.
G aseous cem entation of iron and ste e l. I . Cement
ation b y carbon m on oxide. A. Bramley and A. J. Jin k ix g s (Iron Steel Inst., Carnegie Schol. Mem., 1926, 15, 17—69).—The conditions necessary in order to obtain uniformity of results in gaseous carburisation are defined. In the constancy of other factors, the amount and distribution of carbon introduced by carbon monoxide carburisation depend on (i) the rate of flow of gas, (ii) period of carburisation, (iii) temperature, and (iv) initial concentration of carbon in steel. R ate of flow, whilst greatly affecting the weight of carbon introduced, has little effect on the depth of penetration, whereas both factors are influenced by period of carburisation and temperature. The higher the initial concentration of carbon in the steel, the lower is the amount of carbon introduced by cementation. No evidence of the liqua
tion phenomenon observed by Giolitti was found. In all cases specimens were found to increase in diameter during carburisation. L. M. Clark.
G aseous cem entation of iron and steel. II.
Cem entation w ith pyridine and m eth yl cyanide.
A. Bram ley and G. H. Be eb y (Iron Steel Inst., Carnegie Schol. Mem., 1926, 15, 71—125).—When pyridine and acetonitrile vapours are used as cement
ing agents, no advantage is gained by increasing the rate of flow of the cementing mixtures used beyond a certain value. Depth of penetration is a function of the period of cementation. W ith acetonitrile efficiency of cementation increases progressively up to the highest temperature investigated (1100°), whereas pyridine becomes much less efficient above 1000°. Mixtures of pyridine and carbon monoxide and of acetonitrile and carbon monoxide were also studied.
L .M. Clark. D iffusion of carbon and nitrogen into iron and steel. I. D iffusion of carbon. A. Bram ley and A. J . Jin k in g s (Iron Steel Inst., Carnegie Schol. Mem., 1926, 15, 127—153).—No variation in the diffusivity constant of carbon in iron and steel is caused by alteration of the period of carburisation, rate of flow of the carb- urising gas, or initial % of carbon in the steel, provided th a t the tem perature is kept constant. Variation of temperature, however, has a very marked effect on the diffusivity constant. The relationship is given by the expression log K — 0-00702<—5-730, deduced from the experimental values established. L. M. Clark.
D iffusion of carbon and n itrogen into iron and steel. II. D iffusion of carbon and nitrogen. A.
Bram ley (Iron Steel Inst., Carnegie Schol. Mem., 1926, 15, 155—174).—The diffusivity constants for carbon have been calculated from results of cementations with the vapours of pyridine and acetonitrile, and have been found to be substantially the same as those given in the previous paper. Nitrogen diffuses into iron and
steel in a manner very similar to carbon, and obeys the same laws. The diffusivity constants for nitrogen for a number of tem peratures have been calculated. The weight of the evidence deducible from the diffusivity constants for nitrogen and carbon, together with obser
vations on the distribution of carbon in steel by X-ray methods, is strongly in favour of the solid theory of
diffusion. L. M. Clark.
Effect of constitution on th e m alleab ility of steel at high tem peratures. O. W. El l is (Iron Steel Inst., Carnegie Schol. Mem., 1926, 15, 195—215).—Pure iron forged in the neighbourhood of the A3 point is very much more malleable than material obtained a t tem peratures above or below this point. The forging tem- perature-malleability curve of a 0-9% carbon steel has a marked inflexion a t about 865° whilst the malleability- tem perature curve of any steel, whatever its carbon content, follows a linear law for temperatures above about 1000°. The malleability of a 0-11% carbon steel increases with great rapidity when a temperature of 1400° is passed. This alteration is ascribed not to any change in character of the iron, but to a change in the mode of distribution of the carbon in the solid solution.
In the case of steels containing 0-46, 0-6,0-8, and 0-9%
C respectively, the malleability-temperature curve is strictly linear between 1000° and the solidus.
L. M. Clark. D ilatation of ca st irons during repeated heating and cooling between 15° and 600°. R. Hig g in s (Iron Steel Inst., Carnegie Schol. Mem., 1926,15,217—232).—
Dilatation curves were taken of two series of cast irons containing approximately 1 -5% Si. In the first series the phosphorus was low and the manganese varied ; in the second the manganese was low and the phosphorus varied. The number of heats was limited to 21, the maximum temperature being 600°. The specimens were soaked a t this tem perature for 3 hrs. A small partial oxidation of the iron and graphite occurs. In the manganese series, the growth is due to oxidation and graphitisation, and an increase of the manganese con
te n t stabilises the iron against changes in the coefficient of expansion. In the phosphorus series increase in the phosphorus delays the growth, the phosphorus protect
ing the iron from oxidation. Phosphorus also increases the uniformity of the coefficient of expansion. Grey irons may show no growth after a certain number of heats, b u t their coefficient of expansion may be very
erratic. L. M. Cla rk.
G rowth of com m ercial grey cast iron. C. E.
Pea rso n (Iron Steel Inst., Carnegie Schol. Mem., 1926, 15, 281-—317).—The conclusion of Rugar and Carpenter (cf. B ., 1909,1038) th a t growth, as ordinarily experienced, is primarily caused by oxidation of silicon and iron, and is greater the higher the silicon content of the iron, is confirmed. The rate a t which iron cools after casting influences its susceptibility to growth. Iron heated under oxidising conditions reaches a maximum growth for any one heating within a few hours. Growth in the absence of oxidising conditions is almost negligible.
The sfight growth which occurs on repeated heating in vacuo appears to be due to the occluded gases in the iron.
L. M. Cla r k.
B ritish C hem ical A b s tr a c ts — B.
48G C l. X .— M ju jlls ; ilJtT JO X iaa r, i h c l u d i h o Et*OTBO-MsTALnmaY.
D eform ation of iron, w ith particular reference to sin g le crystals. L. B. Pf e il (Iron Steel Inst., Car
negie Schol. Mem., 1926, 15, 319—380).—A method is described for growing large crystals in \ in. diameter iron rods. Finely-crystalline material and large crystals are employed in a study of the nature and mode of formation of Neumann lamellae, produced by impact.
The orientation of a crystal in relation to the direction of im pact is unimportant. The force of impact determines the position of the lamellfc both in single crystals and in finely-crystalline specimens. After slow deformation, the lamella) can no longer be produced by shock, bu t low-temperature annealing removes the effect of the deformation. The formation of a Neumann lamella produces a step on the polished surface of a crystal, and a step may also be produced a t the intersection of two lamella). The lamellae are not destroyed by pro
longed annealing a t high temperatures. I t is concluded th a t Neumann lamella; are twin crystals, and atomic movements are suggested which would produce twin lamella). Iron crystals with Neumann lamellaj in eleven out of the twelve possible directions have been obtained. Compression tests on single iron crystals are dealt with. I t is shown th a t slip in an iron crystal does not occur on cubic or rhombododecahedral planes b u t on eicosetetrahedral planes. Very large crystals grown in iron strips tend towards one orientation, and the orientations of the crystals grown in round bars are considered in the light of this fact. L. M. Cla r k.
Influence of m an gan ese on the properties of w h ite-heart m alleab le ca st iron. E. R. Taylor
(Iron Steel Inst., Carnegie Schol. Mem., 1926,15,381—
406).—A manganese to sulphur ratio of 1 - 7 :1 gives the best all-round results in a white-heart malleable cast iron, whatever the sulphur content may be. W ith this ratio, the lower the sulphur is, the better are the mechanical results. When the sulphur exists in the iron as ferrous sulphide, as much as 50% may be eliminated during annealing, bu t with the manganese-sulphur ratio of 1 • 7 :1, or higher, sulphur is gained during annealing.
Manganese in greater quantity confers strength without
ductility. L. M. Cl a r k.
A cl ran ge in sp ecial steels. J. H. And rew and H. A. Dic k ie (Iron and Steel Inst., May, 1927. Advance copy, 35 pp.)-—From observation of the sp. vol. and hardness of a series of nickel steels,variation of the carbon content has no effect either on the position or extent of the Acl range, which depends on the nickel content of the steel. The tem perature a t which solution in y-iron commences is lowered rapidly by an increase in nickel, and the am ount of redistribution taking place in y-iron depends on the quantity of nickel originally present in solid solution in the ferrite. Manganese gives an indica
tion of effects similar to nickel, bu t of about 40% inten
sity ; little effect is attributed to chromium.
C. A. Kin g. Pseu d o-tw in n in g in ferrite, and solu b ility of carbon in a-iron at the A1 point. S. Tamura (Iron and Steel Inst., May, 1927. Advance copy, 7 pp.).—
y-Iron and austenite when annealed after being strained readily form tw in s; a-iron and ferrite do not. Twins in ferrite have, however, been observed recently in a sample
of wrought iron and in another of mild steel. The latter was heated first a t 680° for 18 hrs., then a t 900 for 6 hrs., and finally cooled slowly in the furnace, when minute twin like crystals were found in the ferrite crystals. This twin-like structure was found to persist in both specimens after they were heated a t 690° th e one for 2 days and the other for 4 days. This apparent twinning also appeared in the new ferrite crystals after recrystallisation had been brought about by severely straining the speci
men and then heating it a t 690° for 18 hrs. As the forma
tion of annealing twins is closely related to the atomic structure of the metal, and metals which, like ferrite, crystallise in the body-centred cubic lattice seldom produce them, these structures are not definitely stated to be true annealing twins, bu t are preferably called pseudo-twins. The solubility of carbon in a-iron is discussed on the basis of the fact th a t both a- and 8-iron have the same crystal lattice, and on the assumption th a t the point of maximum solubility of carbon in 8-iron lies on the solubility curve of carbon in a-iron, when this curve is extrapolated under specified con
ditions. On this assumption, the solubility of carbon in a-iron at the A1 point is 0-034% (cf. Yamada ; B., 1927,
278). M. E. Notta ge.
Cast iron w ith high m an gan ese content from sm eltin g m anganiferous iron ores b y the S ie m e n s- M artin p rocess. A. W. Sm ith (Iron Age, 1926, 118, 1193—1194; Chem. Zentr., 1927, I., 514—515).—
Manganiferous iron ores may be advantageously smelted to obtain a good cast iron when the manganese content does not exceed about 2%. W ith an ore containing 2% Mn the consumption of fluorspar in smelting is about 12% less than th a t required for an ore with
1% Mn. A. R. Po w ell.
Properties of so m e n ick el-ch rom iu m -m olyb - denum ste els. J. H. An d r e w, M. S. Fis h e r, and J. M. Robertson (Iron and Steel Inst., May, 1927.
Advance copy, 28 pp.).—The therm al and mechanical properties of two series of steels containing 1-6% Cr, 0-87% Mo, 2—5% Ni, and 0-4 (0-8)% C have been examined in some detail. The best combination of mechanical properties was obtained from the steels containing 0 - 4% C tempered a t 625° for 3 h r s .; tensile strength 67 tons/sq. in., elongation 21%, and Izod value 39 ft.-lb. I t is indicated th a t 650° may be within the critical range of high-nickel alloys. C. A. Kin g.
M anganese and its properties : production of ferrom anganese and its history. R. Ha d fiel d
(Iron and Steel Inst., May, 1927. Advance copy, 77 pp.).—The history of manganese is developed from its isolation by Gahn in 1774 to the present day, when over 400,000 tons are used in steel-making annually.
The distribution, production, and average analysis of the manganese ore deposits in Brazil, Georgia, India, and the Gold Coast are discussed, and a map is given showing the ore resources of the world. None of the chief steel-producing countries is self-supporting in its manganese requirements, and the conservation of ferro
manganese by the substitution of spiegel and high- manganese pig iron has been recommended. Manganese ores are chiefly used in the production of crude alloys in the manufacture of steel, also for making dry-batteries,
B r itis h C h em ica l A b s tr a c ts —B .
Cl. X .— Me t a l s; Me t a l l u r g y, i n c l u d i n g El e c t r o- Me t a l l u r g y. 487
and in the glass industry. The m.p. of manganese is 1240°, and the sp. heat up to 1300° is given in a chait.
Present-day manufacture in the blast furnace and electric furnace is described. The chief factor as regards purity is the phosphoric acid content in the ore rather than the process of production. Typical analyses of the blast-furnace products and of special products made in this country are given, together with the production capacity. 80% ferromanganese with 0-6—0-9% C is now being obtained. T. H. Burnham.
N on-rusting steel for flying m achines. T. W.
Dow nes (Iron Age, 1926, 118, 1265—1268; Chem.
Zentr., 1927, I., 518).—For the manufacture of tanks for aeroplanes etc., a steel of the following composition has proved satisfactory: 12-03% Cr, 0-45% Mn, 0-10% C, 0-26% P , 0-03% S, and 0-02% Si, and the
remainder iron. A. It. Pow ell.
Ferroxyl indicator in corrosion research with especial reference to the problem of local corrosion.
U. R. Evans(Metal Ind., 1926,29, 481—482, 507—508 ; Chem. Zentr., 1927, I., 518—519).—The usual ferroxyl indicator comprising a solution of potassium ferricyanide and phenolphthalein in agar-agar is liable to give mis
leading results when used for the detection of anode and cathode areas owing to the ferricyanide acting as cathode depolarising agent instead of oxygen. This difficulty is overcome by using the minimum amount of a solu
tion made by mixing equal volumes of a 1% alcoholic phenolphthalein solution with a 1% aqueous solution of potassium ferricyanide. The cause of local pitting of iron may be due to the presence of particles of iron scale or of minute capillary openings in the surface of the metal (cf. Speller ; B., 1925, 505). In moving water some of the particles of corrosion product formed in the early stages may become detached from the metal and be slowly washed along the surface, thereby giving rise to streaks of corrosion products. The conflicting theories of McKay (B., 1925,136) and Liebreich (B., 1926, 57) are discussed in the light of the author’s own work
on the subject. A . R. Pow ell.
D eterm ination of sm a ll quantities of copper in steel. J. D. Armour(Chemist-Analyst, 1925, [45], 3—5 ; Chem. Zentr., 1927, I., 151).—5 g. of steel are dissolved in 150 c.c. of 1 : 5 sulphuric acid, the solution is nearly neutralised with ammonia and saturated with hydrogen sulphide, and the precipitate collected, washed, and ignited in a silica crucible. The residue is fused with potassium pyrosulphate and the fused mass dissolved in hot w ater; 10 c.c. of an exactly 0-002% solution of copper as sulphate are added, and the total copper is determined iodometrically, allowance being subse
quently made for the added copper. Before titration 20 c.c. of a 10% solution of potassium fluoride are added to prevent interference by traces of iron which are generally present. A. R. Po w ell.
D eterm inations of sp ecific gra vity of iron and low -carbon steel in a m olten condition. D . W . Be r l in (Iron Steel Inst., Carnegie Schol. Mem., 1926, 15, 1—15).—Improvements in the apparatus devised by Benedicks, Berlin, and Phragmen (ibid., 1924, 13, 129) are described. The sp. gr. of four irons and steels of diSerent carbon content are determined. Estimated
mean values for different temperatures, of a preliminary character, are given. L. M. Cl a r k.
Effect of annealing in steps on the specific electrical resistance of hard-drawn w ires [of iron,
Effect of annealing in steps on the specific electrical resistance of hard-drawn w ires [of iron,