Smelting of iron in a normal-working blast furnace may be considered as a pseudo-stable process of momentum, heat and mass transfer between the countercurrent gas and burden flow. Therefore analysis and investigation of gas flow distribution based on equation of continuity and equation of motion is the foundation for further study on heat and mass transfer.The authors study the gas flow patterns of the raceway in cold model. From this studied some important boundary conditions, which affect gas flow distribution in blast furnace, were derived. It has been found that there is a central injection beam of confined-injection type surrounded by circulating currents in the raceway. Some stream-line patterns were derived by finite differential method of Laplace equation and vector form of Ergun equation with electronic computer. Therefore, the stream distribution in the vertical section of the lower part of the furnace and factors affecting the distribution were investigated. Calculated results show that the flow distribution in the lower part of the blast furnace is intimately related with the flow pattern of the raceway and they are helpful for analyzing and controlling the blast furnace process.

The metastable extension of solid solubility of certain simple metals or metalloids in Ag has been studied by means of the lattice parameters measurement when the aUoy specimens quenched from melts. It is found that the solid solubility metastable extension of such elements in Ag that form a lot of peritectic binary alloys with Ag is conformed to the rule of valence electron concentration, but that of those which form eutectic or monotectic alloys does not satisfy the rule. The peritectic alloys may be classified into two types with quite different behaviours of solid solubility metastable extension. It seems to be easily clarified that the influence of the composition range of intermediate phase on the solid solubility metastable extension is more important than its stability. The reason why Si is less soluble in Ag has been also discussed by Miedema's theory.

The hole-structure of doped or undoped W wire in close vicinity to the fused-breaking was observed by metallography. It was found that the K contained in the W wire plays an important role on the formation of hole. The K atoms may move and accumulate along the grain boundaries first. The residual K-bubbles from which the K atoms had lost may be disintegrated into many micropores under high temperature. These micropores migrate in the crystal lattice and collect themself at the grain boundaries where the K atoms accumulated already. A series of holes with various sizes are, therefore, formed. The fused-breaking will take place at the section where the local temperature raised rapidly to an unallow able limit due to the unadaptable increasing of electrical resistance across such section occurring holes.

The effect of thermal cycling between the M_f—A_f temperatures on the thermal hysteresis, temperature dependence, and the morphology of the martensitic transformation in Cu-Zn-Al alloy was studied. It showed that the hysteresis behaviour of cyclic transformation changed, M, and A_f temperature shifted to higher temperatures while the M_f and A_s temperatures remained constant. The amount of martensite undergoing cyclic transformation decreased. These changes appeared to saturate at 300 cycles and could be partly recovered during room temperature holding. The morphology and mode of transformation also changed. During the second cycling transformation occurred in two ways: martensite needles grow in a continuous manner and in a "burst" process. After 60 cycles no burst type transformation occurred during further cycling.

A systematical study was made of the tensile deformation behaviour of 4 different carbon steels, containing 0.10, 0.25, 0.39 and 0.71% C respectively, with initial austenite grain size 800μm under temperature 700—1300℃ at the strain rate 6.7×10~(-4)—6.7×10~(-2)S~(-1). It was indicated that the equation of deformation in the region of austenite phase controlled by the heat activation process is quite agreed with (?)=Aσ_M~nexp(-Q/RT) and the maximum deformation stress is decreased with the increasing of their C content. In the binary phase α+γ region, an embrittlement appears under temperature slightly lower than A_3 point and may become more or less to toughen as the increase of the C content.

The boride precipitation behaviour of steel containing B 18 ppm, N 19ppm and C 0.1% during cooling has been investigated by using the fission track etching and electron microscopy. It was found that the carbon-boride Fe_(23)(C, B)_6 precipitates out along the austenitic grain boundary of solid solution treatment specimen after water cooled even in iced salt water. The Fe_(23)(C, B)_6 appears an acid soluble thin plate on rapid cooling. At the cooling rate up to 20℃/s, the precipitate is further presented in the interior of the grain. Both intergranular and intragranular ones may quickly grow up by isothermal treatment at 750℃. While the isothermal treating temperature raised to 850℃, the boride, to form BN instead, precipitates out around the spherical MnS grain as nucleus of crystallization to obtain a compound of MnS+BN.

In the steel 40BP, during isothermal treatment after austenizing, the BN precipitates out usually around the spherical MnS grain as nucleus of crystallization to form a compound of MnS+BN. When the heating temperature elevated over 1150℃, the MnS becomes polyhedral, but does not be the nucleus of BN crystallization no more. The BN first precipitates as fine spherical crystallite and then as a plate-like single crystal if it grows up to 0.6μm in size.

The tempering behaviour of the matrix steel has been investigated by means of the hardness and strength measurements and TEM observation. It was found that the secondary hardening effect and the resistance to heat softening of the steel are markedly improved by addition of Niabout 1-2%. TEM observation showed that the Ni promotes precipitation of M_2C and transformation of (Fe,M)_3 C as well as fines the grains of V_4C_3 and M_2C. The addition of Ni stabilizes strongly the retained austenite under low temperature tempering. However, the Ni-containing steel tempered under temperature above 500℃ less exceeds Ni-free steel in amount of the retained austenite. The behaviour of increasing the retained austenite does not cover up the effect of strengthening the secondary hardening both by addition of Ni.

The degeneration reaction from MC to M_(23)C_6 at 1030℃ and the reverse reaction from M_(23) C_6 to MC at 1180℃ in a NiCrWTi cast supcralloy have been investigated by the fractographic extraction replica technique. The reversible reaction appeared on grain boundary surface quite markedly.

The effect of micro-amount element additions on the microstructures of Al-Ge and Al-Si-Ge eutectic alloys has been studied by means of metallographic method. For Al-Ge eutectics, no evidence was found of occurring any modification something like that exists in the Al-Si system. Some elements which belong to the ⅣB, ⅤB and ⅥB groups in the periodic table of elements seriously influence their microstructures and change the feather-like Al-Ge euteetic into block Ge crystals. In the other case, it appears to move the eutectic point to the Al-rich side when some alkaline, alkaline earth and rare earth elements were added in this eutectic. The modifiers Na, Sr, La effective in the Al-Si system were scanned about their effects on the Al-Si-Ge system. In this ease, eutectic Si exists in modified clusters form and gradually dwindle their size with increasing the Ge content, finally they disappeared at the Al-Ge side. According to comparison of the modification between the Al-Ge and Al-Si systems, it was considered that the modification of Al-Si eutectic was mainly decided by the effects of modifier atoms on the epitaxial orientation relationship or decreasing the disregistry between {110}_(Si) and {100}_(Al).

The AES has been used to study the composition of the anodic oxide film on 1Cr18Ni9 stainless steel. The film was formed in the transpassive region during the constant potential anodic polarization in H_2SO_4 and after a treatment with Na_2MoO_4. It has been found that the outer layer of the film contains a lot of Mo and the middle layer is rich in Cr. The concentration of oxygen in the rest of the layer up to the interface rapidly reduces to zero. The middle layer in the transpassive anodic oxide film which is rich in Cr is more wider and oxidized more complete than that in HNO_3 oxide film. By comparison with other oxide films, the possible mechanisms for passivation of transpassive anodic polarization are discussed.

X-ray diffraction and thermal analyses were used to study the phase equilibrium relationships in the pseudo-binary system LaNi_5-LaCu_5. The system is of a continuous solid solution. The melting point and the amount of hydrogen absorbed decrease as well as the lattice parameters and the stability of the intermetallic hydrides increase with the increase of Cu content. It was determined that LaNi_(5-x)Cu_xH_n is independent compound in the LaNi_(5-x)Cu_x-H_2 system.The absorption and desorption of hydrogen in the LaNi_(5-x)Cu_x-H_2 system is not a homogeneous and continuous process of hydrogen dissolving in alloy, but is the formation of hydride through hydrogenation of the intermetallic compounds LaNi_(5-x)Cu_x by way of one unit cell by another. The atomic radius of both La and Ni (or Cu) are compressed separately in the alloys LaNi_(5-x_Cu_x, especially in the basal planes perpendicular to the principal axis. This compression phenomenon disappears as soon as the hydrides form.

The metastable hydrides LaFe_yNi_(5-y)H_x of higher hydrogen concentration were prepared by the activation treatment technique under 353—373K and 60—120 kgf/cm~2 hydrogen pressure other than the previous ones. The X-ray diffraction and Mossbauer effect of the LaFe_yNi_(5-y)H_x (0≤x≤1.6) were examined at room temperature. Some interesting informations about their phase transition were given.

Symmetric push-pull fatigue was performed on well annealed 99.999% purity Al specimens with grain sizes up to 10 mm under constant strain amplitude in a Schenck machine. The applied strain amplitudes ranged from ±2.82×10~(-4) to ±6.1×10~(-3). Peak stresses in both tensile and compressive half-cycle after various cycles were measured. A secondary cyclic hardening was observed at all strain amplitudes used. A maximum of the hardening is presented at a strain amplitude of about 3×10~(-3).The metaUograph and SEM observations indicated that at high strain amplitude the various plastic deformations occur in the region of grain boundary which cause the grain boundary glide and migration with intergranular cracking. It was also found that different types of fatigue striations coexist on the same fracture surface.A brief discussion was made of the secondary cyclic hardening which is assumed to result from the local hardening due to the secondary slip and grain boundary sliding.

Stress corrosion cracking (SCC) experiments were conducted with steel D6AC (σ_b=203.5 kgf/mm~2) and 24CrMnSiNi (σ_b=161kgf/mm~2) by dropping water onto the crack opening mouth. The phenomenon of surface deformation induced by SCC has been observed by means of optical and interference microscopes. It was shown that the surface deformation started at the tip of fatigue precrack, then stretched separately into two branches with an angle of 45° to tbe direction of crack propagation and finally turned to parallel to it. For steel D6AC, the width between two deformation bands distributed on both sides of crack propagating direction was narrower and two deformation bands stretched forward by joining together and separating apart alternately. However, for steel 24CrMnSiNi, the two deformation bands, the width between which was found to be wider, did not join together even after stretching forward a long distance. It can be seen from the interference photographs that the fringes were largely displaced at deformation bands, indicating that the surface deformation was mainly concentrated within the deformation bands. In contrast, the fringes corresponding to the area between two deformation bands maintained nearly parallel to each other. The optical microscope observation certified that this area was contracted along the thickness direction. The cracking paths on specimen surface were observed to extend mostly either along the deformation band on one side or the confluence of deformation bands on both sides. The mechanism of surface deformation was discussed. It is considered to be related with the tongue shape expansion of stress corrosion crack over the specimen thickness. Apparently, the uncracking thin surface layers of specimen were subjected to a shear deformation under the action of applied force, resulting in the observed phenomenon of surface deformation.

Based on both the calculating formula for J-integral determined by means of TPB type specimen and the experimental evidence of da/dN=C_1(ΔJ)~r ,an expression of subcritical fatigue crack growth rate characterized by AJ from TPB specimen from the linear elastic to complete yielding region has been derived as follows: For high-cycle fatigue crack, its approximate growth rate will be which seems to be identical with the Paris' relation. For high-stain fatigue crack, it may be which is analogous to the Coffin-Manson's relation.These formulae are confirmed by the experimental results for steel 16Mn specimens in the environment of atmosphere or aqueous H_2S saturated solution. It is also indicated that the aqueous H_2S saturated solution may aggravate the subcritical growth rate of fatigue cracking.

A study was sought for a calculational method of the phase boundary determination in a binary system phase diagram other than the previous conventional ones. When two phases are in equilibrium in the binary system under certain given temperature, two transcendental equations may be obtained. The proposed method will be developed by ploting one of these equations on diagram, working out several sets of solutions to fulfil this equation and then inserting into another equation for numerical approximation. Based on the present method the computer will show the phase boundary correctly and directly if its mathematical expression is given.

The load oscillogram for the hammer drill steel is presented to predict the fatigue behaviour and the service life under drilling conditions. Experiments were conducted to measure the longitudinal, flexural and total waves at the front, middle and back parts of the drill steel during drilling granite and limestone. Certain available results have been obtained to expound its failure mechanism and to further develop new type of steel.