An investigation was carried out on the reduction disintegration properties of two typical sinters made from Chinese high grade magnetite iron ore concentrates produced by Qian'an and Ma'anshan areas. The test was carefully compared with that of Australia hematite ore fines in a specially designed rotary tube. It was found that the worst resistance to the reduction disintegration seems to be displayed for the Chinese sinters with the basicity CaO/SiO_2 in the region about 1.7—1.8 and under temperature of reduction at 500℃, as weU as it has much improved since the CaO/SiO_2 ratio beyond the region, namely 1.0 or 2.5. WhiLst the reduction disintegration index of the Australia hematite sinter decreases with the increase of its basicity.By changing the test temperature of reduction and adopting H_2 as a reducing gas instead of CO, an examination of the sinters on the entire reduction process under petrographic microscope shows that the reduction disintegration properties of Chinese magnetite sinters with different basicities are closely related to their mineral composition and microtexture. The carbon deposition may bc also an important factor affecting their reduction strength. However, the phase transformation of Fe_2O_3 during reduction influenced them slightly due to its small content.Experiments were also made of the properties of the sinters in 55m~3 blast furnace, in which a perforate steel probe tube filled with several Myers of testing sinter and coke was inserted. The result is very conformable to that in the rotary tube.

The effect of boron on the high temperature strength of an Fe-42Ni-12Cr-4W-1. 5Mo-4.5Ti-2Al alloy has been investigated. The results indicate that the boron either soluted in solid solution or precipitated as a secondary boride phase along the grain boundaries will improve the stress rupture properties of the alloy. But the primary borides can not better it at all, moreover, it may deteriorate the high temperature strength of alloy if an overabandant primary boride occurred. It was also found that the stress rupture properties of alloy have much improved since it solution treated under elevated temperature, this seems to attribute the improvement to the increase of the amount of secondary boride precipitation at unit interface area after solutioning and aging, not to the grain growth alone from higher solution temperatures in the tested range of grain size.

The effect of the hydrogen content in the ingot on the medium temperature tensile ductility of an alloy GH132 has been investigated. Various hydrogen contents in thee ingots were produced by maintaining the equilibrium on different pressures of hydrogen input in a vacuum induction furnace and the alloy melts before casting. The results show that no matter what the original hydrogen contents, e. g. 2.0 to 19.6 ml/100 g, of the ingots are, neither marked difference to the ductility between high and low hydrogen containing ingots nor low tensile ductility region under medium temperature is found if the ingots are dehydrogenated to such extent of similar hydrogen content about 0.5 ml/100 g.The influence of trace Pb on medium temperature tensile ductility of the alloy has also been studied. Serious ductility deterioration was found and low tensile ductility region under medium temperature was obtained when Pb exceeded 2 ppm. This harmfulness may be explained by the diminishment of the granular strength and the equi-strength temperature of GH132.

The effect of 12 elements such as Li, Na, K, Mg, Ca, Sr, Ba, La, Sm, Y, Sb and Bi on the modification of the Al-Si eutectic alloys was systematically investigated by means of their microstructure observations. The range of modifying concentration for each modifier under various cooling rates was detected and their effects on microstructures of Al-Si eutectic alloys with same modifier concentration but varied cooling rates were also studied. A critical cooling rate, v_c, of modification is always presented for each own modifier. The modification does not occur at a lower cooling rate than v_c with whatever the concentration of the modifier. The lower the v_c of a modifier, the stronger will be its modifying ability. Among these modifiers studied, the modifying abilities of Na, K, Sr and La with their v_c values lower than 40℃/min are the strongest. It seems to be suggested that v_c is available for a quantitative scale of the modifying ability assessment of a modifier.

Three-point bend tests were conducted on the high cycle and high deformation fatigue crack growth rate of steel 16MnRE in aqueous H_2S saturated solution under different temperatures. Their corrosion fatigue activation energies were measured as 9.45 and 9.25 kcal/mol respectively. It may be proposed that the behaviour of corrosion fatigue cracking of steel 16MnRE in the saturated H_2S solution is mainly due to the hydrogen embrittlement and the rate of their crack growth is controlled by the hydrogen atom diffusion in steel.

A metallographic investigation was made to follow the dynamical process of the initiation and propagation of hydrogen induced delayed cracking (HIDC) toward a charged modified WOL specimen made of high strength Al alloy. It was shown that the size of the plastic zone in front of crack, namely hydrogen induced delayed plasticity (HIDP) was continuously enlarged with time prolonged. Development of HIDP to a critical value leads to the initiation and propagation of HIDC as well as SCC in high purity water or 3.5% NaCl aqueous solution. The effects of testing temperature, polarization voltage and chlorine ion on K_(ISCC) and da/dt in high purity water are found to be identical to the influence upon the amount of hydrogen evolved when the specimen immersed in HCl solution of pH=3.5 or 1.0. These results may support such viewpoint that HIDC plays an important role in the behaviour of SCC of high strength Al alloy in aqueous solution.

A discussion on the catalytic action of clean surface of LaNi_5, by which the molecular hydrogen disassociated into atoms, is presented according to the study of the activation process kinetics of LaNi_5. It was confirmed that the catalytic action will be poisoned by oxygen on its surface. The activation process is removal of the pollution by oxygen and thereby forms a clean surface. How the incubation period come into existence is due to the surface pollution. The unreleased hydrogen stored in activated LaNi_5 can relieve the influence of oxygen upon the surface activity of it.

The diffraction contrast study was carried out on the deformation and the crack propagation process of WC-12%Co cemented carbide and on the mechanism of phase transformation of binder Co by TEM including weak-beam technique. It indicates that the deformation behaviour of the alloy depends upon the coordinating strain ability of binder Co, and that the characteristic morphology of the crack propagation seems to bear a direct relation to the slip structure of WC with binder Co and the properties of interfaces. The cracks propagate linearly along the intra- and transgranular fracture of WC,WC/WC and along WC/Co interface as well, but zigzaggedly in the binder Co. The β-Co (fee) is unstable at room temperature and very easy to transform into ε-Co (hcp) even by a smaller driving force of the phase transformation, e. g. the alloy subjected to deformation. It may be believed that this transformation undergos the growth and thickening of the stacking faults lamellae in the β-Co and thereby the formation of a stable ε-Co of hcp structure finally.

The temperature dependence upon the viscosity of three metallic glasses PdCu_6Si_(16.5), PdNi_6Si_(16.5) and CuZr_(43) has been determined by the creep method near the vitrification temperature tange. Under the Newtonian viscous region, this dependence may be described by the Fulcher-Vogel equation. The constants of this equation were determined experimentally and the apparent activation energy of viscous flow for these three glasses was calculated therefrom. The activation energies of thermal transformation of the glasses PdNi_6Si_(16.5) and CuZr_(43) were also determined by differential scanning calorimetry. It was found that there is no appreciable difference in activation energy between viscous flow and thermal transformation for PdNi_6Si_(16.5), but marked for CuZr_(16.5).

A new approach to the analysis of both X-ray and electron diffraction patterns of single crystals is presented. It consists in the rotation of the reciprocal axes of the crystal by computer.Based on this principle, a computer program, written in BASIC, is compiled for all crystal systems and has been used successfully for the indexing of both X-ray and electron diffraction patterns and the determination of crystal orientations. In addition, the same program with little modifications has been also used to plot the standard projections and simulate the Laue and electron diffraction patterns automatically.

By means of metallographic microscope and SEM the correlation between the feature of etch-pits and the grain orientations in bcc metals has been investigated. The grain orientations were determined by ECP in SEM and illustrated in a unit stereograph triangle. A series of their relational expressions was deduced with aid of vector analysis and coordinate transformation method. Some tables and charts, on which the grain orientation can be rapidly consulted, have been constructed by collection of the theoretically computed data. The analyzed results of the grain orientations may be directly expressed in a unit stereograph triangle and also easily determined on the transformation matrix of the grain boundaries, because the shapes of etch-pits are described by a continuous function of azimuth angle (θ, φ). Certain metallurgical problems have been discussed by the application of this analytical technique.

Considering the effects of adhesive layers and filaments supporting the composite resonator on the measurement of the internal friction and modulus, the accurate expressions for the internal friction and elastic modulus have been obtained by solving the partial differential equations of the correlative variations of composite resonators. The additional internal friction due to adhesive layer is proportional to the product of square of amplitude of the strain in the layer and the internal friction of adhesive. The internal friction owing to supporting filaments is found to be proportional to the internal frictions of specimen and of quartz resonator.The non-linear and non-steady internal friction backgrounds caused by flowing and cracking of adhesives observed in the internal friction measurement of low damping specimen were explained. It was also suggested some effective approachs to raise the precision of the measurement of internal friction by Marx method.

Studies were made of the relationship between the phase structure and transformation in Fe-Al aUoy and the valence electron state, as well as the mechanism of the phase transformation therefrom. The dependence of the composition and heat treatment schedule upon the variation of the magnetic moment and the plasticity has been theoretically explained. Especially, the number of Bohr magneton calculated is in good agreement with those experimentally determined.

Five phases were determined by means of quantitative EPMA, SEM, X-ray diffraction, etc. in the high Ti-slag with high Mg and Ca contents, smelted by 6000 kVA electric furnace. The principal phase is the anosovite solid solution of Ti_3O_5 type in amount of 87.06% of the slag. Along the grain interfaces of the solid solution phase, CaO concentrated mainly in the form of 2CaO·TiO_2. This is the phase area so called the crystal phase enriched Ca and Mg. Most MgO is collected in the glass phase which is about 10.90% of the slag. Other two minor phases are found to be Ti-Fe alloy and metallic Fe. Thus, the calculated structural formula of such an anosovite in the slag seems to be: 0.15[(Mg_(0.27)Ti_(0.73))0.2TiO_2]·0.85[Ti_2O_3·TiO_2]

The anomalous Hall coefficient and Ohm resistivity measurements other than current techniques were carried out on the study of the crystallization process of three amorphous magnetic aUoys such as Fe_(62)Ni_(16)Si_8B_(14), Fe_(40)Ni_(40)P_(12)B_8 and Fe_(7.8) Co_(46.8)Ni_(23.4)Si_8B_(14). A sudden change of the relative coefficient was occurred with very distinguished extent about 2 times from the relative resistivity. It would like suggested that the anomalous Hall coefficient is an effective parameter for studying the crystallization process of amorphous magnetic alloy.

An analysis and discussion were made of the evidence whether the conventional differential equation is proper to calculate the dynamic transition process. It has been proved that the equation is applicable to all continuous rolling conditions of tension less than the elastic limit, however, the error may only be introduced by the neglected term (1+σ/E). The analytical solution of the equation gives not only clarifying the physical nature of rolling practice but also improving the accuracy and amount of the dynamic analogue calculation. Combining the aforementioned conventional differential equation with the balance equation of total tension, a discrete tension formula is then derived for dynamic guage change and strip threading procedure.