Metallographic studies of antique iron utensils that had been unearthed in various parts of China revealed the structures of white cast iron, hammered low carbon steel, and black heart maleable iron, indicating that our ancestors in the 3rd or 4th Century B.C. had already mastered the art of making these materials.Brief descriptions are given of an excavated crucible furnace for iron smelting, of the possible ways of converting white cast iron into malleable metal, and of ancient methods of making swords.

The chlorination equilibrium of cobalt sesquioxide has been investigated by the circulation method. Within the temperature range 673—923°K, the equilibrium constant and the standard free energy of the reactionCo_3O_4(s)+3Cl_2(g)=3CoCl_2(s)+2O_2(g) have been found to belog K_p=(404/T)-0.304,ΔG_T~O=-1850+1.39 T.or log K_p=(4509/T)+12.28 log T-41.13,ΔG_T~O=-20630-56.2 T log T+188.2 T.The thermodynamic data reported in previous literature are very divergent. They are critically examined and compared with our data.

The chlorination equilibrium of nickelous oxide has been investigated using the circulation method within the temperature range 666—928°K from both sides. The reaction is established as NiO(s)+Cl_2(g)=NiCl_2(s)+1/2O_2(g). The equilibrium constant and standard free energy of this reaction may be represented aslog K_p=(2720/T)-2.312ΔG_T~O=-12450+10.58 T.The result is found to be in good agreement with thermodynamic data in the literature. The maximum error for ΔG_T~O is estimated to be about +300 cal. At lower temperature, the experimental results of show some deviation from our data, probably due to unattainment of equilibrium in his experiments.

The chlorination equilibrium of cupric oxide has been investigated using the circulation method. Within the temperature range 300—450℃, the reaction is found to take place in two stages, and the following results are obtained:2CuO(s)+Cl_2(g)=Cu_2OCl_2(s)+1/2O_2(g), (1)logK_p~Ⅰ=(3061/T)-2.228,ΔG_Ⅰ~O=-14010+10.20T.Cu_2OCl_2(s)+Cl_2(g)=2CuCl_2(s)+1/2O_2(g), (2)logK_p~Ⅱ=(2370/T)-1.90,ΔG_Ⅱ~O=-10850+8.69T.The physical properties of the intermediate compounds have been studied, and within the given temperature range, the average enthalpy of formation of the intermediate compound Cu_2OCl_2 is found to be -84900 cal./mole; and its average entropy of formation to be -51.23 e.u.

On the basis of a proposed reaction mechanism for cementation of copper from its aqueous solution by means of metallic iron, the authors suggested a method employing fluidized iron pellets for recovering copper on an industrial scale.During the initial stage of the reaction, the rate of cementation conforms to a firstorder reaction controlled mainly by the concentration of copper ion at the iron-copper boundary. As cementation proceeds, however, metallic copper collects as a porous layer on the iron, and diffusion of copper ion through this layer becomes the rate-controlling step of the process.Experiments on cementation of copper in a conical bed of fluidized iron pellets indicate that the copper layer formed peels off continuously as a result of the turbulent motion of the stream and mutual collision of the iron pellets, and is thus carried away by the flowing liquid from the reaction zone. The adoption of the conical bed insures complete fluidization of all the iron pellets having a wide particle-size range which results from their different residence time in the cementation reactor. The operation of a fluidized cementator is simple and is particularly adaptable to automation. When cast iron beads are used, 90% of the copper contained in a 0.1% Cu~(2+) solution is recovered at an operating temperature of 75℃ during an average solution residence time of 20 seconds.

The effects of molybdenum, tungsten, vanadium and boron on the properties of Cr-Mn-N steels have been investigated. The high-temperature properties of a nickel-free austenitic steel selected from systematic study have been described. The results suggest that the steel studied might be suitable for service temperatures up to 650℃.

The isothermal sections at 1200℃ of the systems Mo-Ti-Zr and Mo-Nb-Zr have been determined by metallographic and X-ray diffraction methods supplemented by hardness measurements. The constitutions of these two systems are strikingly similar; besides a b.c.c, ternary terminal solid solution and a ternary Laves phase isomorphous with MgCu_2 structure, no new intermediate phase has been found.In the Mo-Ti-Zr system the lattice parameter of the ternary solid solution increases with the increase of Ti or Zr in solid solution, and the ternary Laves phase is (Ti, Zr) Mo_2. In the Mo-Nb-Zr system, the lattice parameter of the ternary solid solution also increases with the increase in the Nb- or Zr-content, and the ternary phase in this case is Zr(Mo, Nb)_2.The iso-hardness contours of the Mo-Ti-Zr system tend to expand towards the titanium corner as the Ti-content is increased, whereas those of the Mo-Nb-Zr system expand towards the niobium corner with the increase in Nb-content in a like manner.

Mild steel specimens were exposed to synthetic blast furnace exhaust gases of the following composition: HF 0.05—5%, H_2 1.5—2.5%, H_2O 0—1%, CO_2 6—8%, CO 19—23%, N_2—hal., at a temperature range of 250° to 530℃. Below ～390℃, the corrosion product was identified by X-ray diffraction as FeF_2 and formed a compact protective film. It was further observed that the existence of H_2 in synthetic gases greatly retards the formation of FeF_2. Above ～390℃, FeF_2 first formed is transformed immediately into Fe_3O_4 by the reaction with the existing water vapor. Even in a dry synthetic gas under this temperature range, the reaction of CO_2 and H_2 will produce sufficient partial pressure of water vapor to drive this transformation to its completeness. These results conform with the existing thermodynamic data. On increasing the HF concentration from 0.05% to 5%, no obvious enhancement of corrosion rate of mild steel has ever been noted below 390℃.

A spectro-chemical method, for the analysis of trace of impurity elements (Pb, Bi, Sn, Sb, As) in one kind of Ni-alloys, was developed, with D.C. arc powder excitation following H_2S pre-separation.Owing to the needs of long periods of operation and large amount of reagents, the use of A. R. grade reagents led to a considerable blank value. After using purified reagents, the blanks (for Pb, Sn) were reduced to a μ-gram range.During the arcing of the specimens, the evaporation of arsenic was found to be very imcomplete. The addition of P_2O_5 accelerated its evaporation very obviously. While the sample being utilized efficiently, the sensitivity of arsenic increased 4—5 times. It was noticed that at the position of the line As 2349 (?), the band spectra of carbon ignited in air was very obvious and a correction must be made.Results of experiments showed that standard samples could be prepared by the H_2S treatment of pure standard solutions. The usual blank correction of the matrix could thus be avoided.An analytical procedure was suggested and the results of three specimens were listed. These data showed teat the lower limits of analysis of this method were: Pb:0.0001%, Sn, Sb:0.0002%, As:0.0003% and Bi:0.00002%.