The elastic properties of as-cold-rolled and of the subsequently annealed sheets of a phosphorus steel having high normal plastic anisotropy and low planar plastic anisotropy have been calculated according to the averaging procedures of Voigt, Reuss, and Hill incorporated with texture-weighting functions. The calculated values of Young's modulus in the various directions lying in the plane of the sheet were compared with those determined experimentally by ultrasonic measurements. Results indicate that the Hill averages are very close to reality, whereas the Voigt and Reuss averages are somewhat too high and too low, respectively, in comparison with experimentally measured values. This paper has been prepared to help familiarize metallurgists, engineers and students with the mathematical treatments that can be used for such studies. The procedures used for the calculations are described in detail, and examples of calculations are proveided in the Appendix.

With the object of examining the high temperature corrosion damage of seven conventional cast superalloys, the experiments were made of the exposure of representative specimens to burning natural gas in the steam boiler combustion chamber under temperature between 700—850℃ for a long-term up to 13000h. The following observations with specimens have been done: macro-and micro-metallography, weight changes, X-ray diffraction analysis, EPMA, glow discharge emission spectroscopy, etc. The alloy K18 was corroded seriously to swell and to crack; K3 and K19 appeared with some small protuberances; and the rest suffered corrosion slightly. These alloys in sequence of resistance to corrosion damage seem to be as follows: FSX414, M38, 537, K17G, K3, K19, K18. Their corrosion behaviour have also been discussed in detail. The presence of Cr,Ti,Al enriched layer in the oxidizing scale is regarded as an important factor for their resistance to high temperature corrosion.

Using polished cantilever specimens made of two high strength steels 40CrNiMoA and AISI4330M, the nucleation and propagation on stress corrosion cracking in distilled water have been traced by metallographie shadowing technique. The morphology of sub-critical crack growth has also been observed. It was indicated that the shadow zone, i.e. a plastic deformation area in the front of crack tip, reveals. its different morphologies in various steels. In 40CrNiMoA, the shadow zone grows and joins one another with the crack propagation. In 4330M, it does not join together, but develop along two parallel paths. The catlike shadow zone immediately appeared at the crack tip after loading can be considered as the plastic zone at the crack tip. However, the shadow zone hereafter observed during whole process of the crack propagation seems not to present the plastic zone at the crack, but to represent the deformation induced by. the formation of shear lip and can be related closely to the pop-in. This should be distinguished from the plastic zone at the crack tip in the linear elastic fracture mechanics.

The precipitates in 13Ni maraging steel (280 kgf/mm~2) have been identified in relation to the orientation of σ and δ phases in martensite matrix by means of X-ray and selected area electron diffraction analyses. It was shown that the precipitates as an intermetallie compound of δ-(Fe,Ni,Co)Mo are responsible for strengthening in the steel. In case as-forged after aging, μ-phase appeared may reduce its toughness. After over-aging, e. g. 580℃ for 16h, a. c., some reverted austenite was formed. From observation in situ on heating the aged specimen in electron microscope up to 743℃, the δ grains were coalesced and the needle-like σ phase precipitated. Though the diffraction patterns of δ or σ phase can be commonly indexed, the difference of orientation between δ/α and σ/α seems to be more easily used to distinguish them in the maraging steel.

The accumulation of non-equilibrium defects in the thin metal films during electromigration may cause to increase their resistance. The change of the resistivity has been derived as either of the following equations:d(ΔR/R_0)/dt=cmj~2ρ~(3/2)Z_i~*eD_0/λ~(1/2)kT exp(-Q/kT) and d(ΔR/R_0)/dt=c_1mj~2ρ~(3/2)Z_i~*eD_0(2(T-T_e)+α(T-T_e)~2)~(1/2)/λ~(1/2)kT exp(-Q/kT) by which the activation energy of elecromigration, Q, in the thin metal films is quite easily determined. For example, in the Al-3.2％ Cu alloy stripe, Q=0.65±0.04 eV, calculated by the former equation; and in pure Al film, Q is agreed to the Hummel's result, after treated his data and calculated by the later one.

A concept, Fuzzy symmetric group, is introduced and subsequently applied to the description of short-range order in the structure of amorphous solids.

The semiempirical rules of the thermodynamical properties of oxide systems have been proposed by the pattern recognition technique with chemical bond-parameter, and an empirical function L has been suggested as a scale for the acidity or basicity of oxides. It seems to indicate that the correlation between L and such physico-chemical quantities as the heat of formation of complex oxides, the heat of mixing of oxide melts, the activity coefficient and polymerization equilibrium constant K_(1,n) of Masson's model of slags may be presented respectively. The applications of L function are illustrated with some examples.

Estimation of threshold value ΔKth in fatigue crack growth of different REMg ductile irons under lower stress revealed that the existence of ΔKth in the irons is affirmed. The ΔKth decreases in value with the increase of either pearlite occurred in matrix or phosphorus content. The processing such as the metal-backed shell mold casting and gas soft-nitriding may increase the ΔKth in certain extent. Under lower fatigue stress, the blunt effect of graphite nodules at the tip of crack causes the ΔKth value to be greater than that of common structural steel. While the stress approaching the critical value of unstable crack propagation, the stressconcentration effect of graphite nodules decreases the resistance to crack propagation, thus causing its fracture toughness lower than that of the steel. The σ_(-1) value which represents the energy required for crack initiation is dependent upon the strength of ductile iron matrix, and the ΔKth value which represents the energy required for crack propagation is dependent upon the toughness of matrix. The effects of various matrix microstructure on these two values are contrary. A combined consideration of both values would be taken on selection of materials used.

The principal mineralogical constituents of fusion-cast magnesite chrome refractories were identified as periclase solid solution, intergranular spinel and forsterite solid solution. Their amount and composition, their crystal size and some of the optical properties are determined and their empirical formulae have been predicated. The characteristics of each type of microstructure observed as well as the conditions of its formation are discussed. Such brick after service in copper flash smelters may be distinguished into slag zone, reaction zone and unaltered zone. It is due to the thin reaction zone and absence of a transition zone that no penetration of low melting phase has substantially occurred. From the results of chemical analysis and petrological observation of various zones, it may be concluded that the main attack comes from the ferrous silicates and iron oxide in the slag which corrode the periclase and spinel in the brick, and that the periclase is more easily eroded than intergranular spinel. The basic requirements for the microstructure of the brick for service in copper flash smelter are discussed and measures for control of the microstructure have been suggested.

The positron annihilation techneque is avaible to measure the dislocation densities of not only pure metals but also high alloys within the range of 10~(12)cm~(-2).

Central cracked and single edge cracked α-Ti specimens were loaded up to different stress levels and cut into four test pieces after unloading. Both parameters, positron lifetime and Doppler broadening lineshape S parameters were measured in the plastic zone at the crack tip. The Doppler broadening lineshape S parameters were measured as a function of distance from the crack tip along the crack direction, It was found that the S parameters decrease monotonically along the crack direction until the boundary of the plastic zone is reached. The size of plastic zone estimated by the positron annihilation method seems to agree roughly with that obtained from that calculated by fracture mechanics.

The abnormal segregation of Mn along grain boundaries in an austenitic steel containing 26％ Mn was identified by both Auger energy spectrum and ion microprobe analysis. The morphology of its high temperature fractogrph is shown as brittle intergranular fracture instead of normal ductile dimple.

The steady state creep rate of alloy Ti-679 under various temperatures and stresses was examined. A cyclic test on strain rate was also made of its apparent activated area as a function of temperature. Some approaches to the creep mechanism of the alloy are discussed.

An expression is proposed for the relationship between the contact angle of glass on Pt or its alloys and glass viscosity,θ=pη~q, on the basis of derivation of their temperature dependence, log θ-1/T and logη-1/T. Value p or q is parameter charaterized by the glass-Pt alloy interface energy, as well as the constitution of glass and wetted metal or alloys and interaction between glass and metal. The idea of bond parameter is suggested to correlate with the values p and q.