The intermediate heat treatment under different temperatures was adopted tomodify the type, shape and amount of the grain boundary precipitate phases. Theimpact toughness of the alloy after intermediate heat treatmeni was evaluated atroom temperature and -196℃. Observations under SEM and TEM were carriedout on the impact fracture and its extraction replica. Resutlts showed that thesecondary TiC densely precipitates along grain boundary as thin flakes whichare exactly like a thin brittle coating over grain, but on the other hand, thegrain boundary TiC precipitates in less amount, and the notch sensitivity forstress rupture is found in the alloy. When the TiC or Laves-phase precipitatedas coarser and thicker flakes or as granules along grain boundary, the alloy hasno notch sensitivity. However, when the grain boundary TiC precipitated lessor distributed as granule, the alloy is improved over its impact toughness andthe impact fracture is transgranular. When the TiC or Laves-phase as-flakes dis-tributed along grain boundary, the impact toughness of the alloy is worsened andthe impact fracture is intergranular.

The effect of 0.22% Zr, and in comparison with Mn, Cr or Cu in theauthors' previous works, on the precipitation, the critical nucleation temperature,T′_c, and the microstructure parameters of a commercial purity Al-5.0Zn-1.75Mgalloy has been studied by means of hardness test, optical microscopy and TEM.The results obtained showed that Zr is the element by which the recrystallizationtemperature of the alloy is substantially raised and the grain size is refined, butthe T′_c is not yet increased. When aged at temperature≤160℃, an additive ofZr in the alloy may inhibit GBP, promote MPt and increase HV. However, whenaged at temperature≥180℃, it may sharply increase these parameters and vio-lently decrease HV. The width of PFZ in the Zr-bearing alloy is always narrowerthan that in the Zr-free alloy under a selected aging condition at 120--200℃. Ithas also been tried to make approach to behaviour of Zr added in the alloy andto contrast among the additives Zr, Mn, Cr and Cu.

The alloying element V has remarkable influence on the ordering phase sepa-ration in the Fe-Si alloy containing 6.5 wt-%Si. The behaviour of V was inves-tigated by magnetic method, X-ray diffraction and electron microseopy. It wasfound that an addition of less amout of V may relax the ordering phase sepa-ration and improve the ductility and magnetic properties of the alloy. An A_2+DO_3 ordering phase separation was observed in the 11.57 at.-%Si-Fe alloy con-taining more V, namely, 0.88 at.-%. Discussion has been made of the effect ofV on the ordering phase separation in the Fe-Si alloy on the basis of analysisof thermodynamic data of three binary alloys of Fe-Si, Fe-V and V-Si.

The effect of aging on the thermoelastic martensite transformation of thecommercial. pure Cu-17.99 at. -%Zn-13.63 at.-%Al alloy with M_s over room tempe-rature has been studied by means of the measurement of electrical resistance.When the alloy was fully aged in the martensite state immediately after quench-ing from high temperature in the disordered β-phase region, the thermoelasticmartensite may be stabilized and featured no more in the thermoelastic transformation or reversal on the resistance-temperature curve. When the alloy was agedin the β_1-state immediately after quenching, as the aging time prolonging, thefeature of the thermoelastic transformation may be maintained gradually, as wellas the phase transition temperature and the relative amount of reversible transfor-mation of martensite may be gradually tending towards a stable value. In thethermal cycling afterwards, these seem to change no longer. It is suggested thatreordering in the martensite might coniribute to stabilization after aging in themartensite state.

The quantitative metallographic observation of altered carbide microstructuresin the matrix and test of hydrogen embrittlement for a low carbon Cr-Mo-Vsteel undergone different regimes of heat treatment were conducted. The experi-mental results are believed to support the authors' previous prediction that thedistribution and shape of the catbides affect obviously the susceptibility of HSLAsteel to hydrogen embrittlement. The measurement of apparent diffusion coeffi-cients of Q+T and N+T specimens revealed that the values of D increased withthe increase of tempering time, suggesting that the density of traps was reduced.

The process of hot corrosion of Ni-16Cr-2Nb wrought alloy was studied bythe method of Na_2SO_4 deposit containing isotop ~(35)S in the temperature range of910--1020℃. The ~(35)S autoradiography showed that the sulphur diffused alongthe grain boundaries of the alloy preferentially, forming metallic sulphides there.The sulphides were then oxidized and released free sulphur which might form newsulphides at grain boundary and be dissolved into grains and transport inwardby volume diffusion. No direct relation was found between the internal sulphi-dized depth and the weight gain of hot corrosion of the alloy. Experimentalresults provide a new proof about the mechanism of internal sulphidation-inter-nal oxidation during hot corrosion.

Study was made of the effect of addition of 0.3% Ce on the preferred ori-entation of grains in oxide scale formed on Fe-15Cr alloy at elevated temperatureby the inverse-pole-figure method. The main orientation is (101 10)_⊥, (1014)_⊥,(1126)_⊥ or (1014)_⊥, (1126)_⊥, (0112)_⊥ for the alloy containing or not respectively.The Ce was found to be accumulated at the interface between the oxide scale andalloy. The presence of Ce appears to have an improving effect over the oxidationresistance of the alloy owing to enhancing and keeping the preferred orientationof grains in oxide scale.

The recrystallization technique has been applied to the measurement of theplastic strain distribution within the imense strain region at the crack tip of centrecracked tension specimens. The quantitative relations between the parameters ofthe intense strain region and J-integral and crack tip openning displacement(COD) are obtained. At the same time, three dimensional finite elementmethod analysis is carried out from the theoretical aspect. Both the experimentaland the analytical results show that the recrystallization technique is a very effec-tive method for investigating the three dimensional elastic-plastic crack problems.

The vapour pressure of Mg, P_(Mg), over their thermal reduction of Mg withreducing agent, a high Al alloy containing Si 18.9% and Fe 5.1%, at varioustemperatures was measured by the transportation method as:lg P_(Mg)=-8853/T+10.58As compared with ferrosilicon as reducing agent, the reduction temperature maybe reduced about 200℃ at the same P_(Mg). The activity of each component inAl-Si-Fe alloy at various temperatures was calculated using the data measured byboth Bonnier method and this study. The activities of all components in theternary system have negative deviations, especially, very high for Fe. Based onthe above-mentioned data of the activities, the equilibrium constant and enthalpyof the reduction were also calculated as follows:lg K_[Al]=-18.4×10~4/T+117.2△H=3529.5 kJ

The surface tension of liquid Ni-P and Ni-Zr-P alloys and their wettabilityonto Al_2O_3 substrates were measured by the sessile drop method. The distributionof P along the depth beneath the surface of the alloy was determined by AES.Results show that the P is a surface-active element in liquid Ni and the surfacetension of liquid Ni-base alloy is obviously decreased by the increasing of P con-tained when a small amount of Zr existed. The maximum adsorption value ofP on the liquid Ni surface is rather close to the measured value by AES. Thewettability of Iiquid Ni-P onto Al_2O_3 is concerned with the P content in the all-oys and decreases as less Zr contained in them. The apparent shearing strengthof the Ni-base alloys against Al_2O_3 substrate was also evaluated.

The interaction of chalcopyrite with Na_2S_2O_3 and CuSO_4 has been studied byanalyses of infra-red spectra and electron spectroscope. Experimental results showedthat the reaction product of Na_2S_2O_3 and CuSO_4 attaches to the surface over chal-copyrite grains by chemical adsorption. A severe toxic cyanide, therefore, maybe replaced by Na_2S_2O_3 and CuSO_4 in the flotation of Mo or Cu-Mo ore actingfavourably as depressor of Cu containing mineral.

A simulation of heat transfer from the water droplet sprayed over the hotsurface of low carbon steel bar of continuous casting has been made. The distri-bution of water spray flux density of full cone nozzles and the heat transfercoefficient have been determined. The surface temperature of casting steel bar, thewater spray flux density and the speed of water droplets as well as others in-fluenced on the heat transfer coefficient have also been discussed.

The variables concerning the heat engineering of a flame furnace may be clas-sified into three groups: (1) the design and operation variables; (2) thermopro-cess variables and (3) the performance variables, which have been studied compre-hensively using an analytical method. In several typical cases, the results weredrawn on charts and set on tables to make clear on the performance of flamefurnace. An empirical method has also been proposed for studying the relationshipbetween the 1st and 3rd groups of variables and many production furnaces havebeen analysed. The principal ways of saving furnace fuel were pointed out. Theempirical method here introduced is entirely based on the production data. simplic-ity itself, and no measuring tool is necessary.

The magnetizations, M_8 and M_(20), at the field H=8 and 20 kA/m respective-ly, of ribbon metallic glasses (Fe_(1-x) Co_x)_(78)Si_(10)B_(12) (x=0.1, 0.5, 0.7 and 1) afterannealed at T_a=350-500℃ have been measured. It was found that the initialcrystallization makes the saturation magnetizing of the metallic glasses hard, andthe M_(20) of them with x=0 and 1 decrease but with x=0.5 and 0.7 increase. Thisseems to be. explained by a magnetocrystalline anisotropy in the crystallite ofFe_(1-x)Co_x and a stress anisotropy in amorphous matrix.

The temperature dependence of the saturation magnetization of amorphousCo_(100-x)P_x (x=13.9-27.7) alloys prepared by electrodeposition was measured by amagnetic balance in the field 12 kOe between 77 and 1300K. The average magneticmoment per Co atom, from low temperature measurements, decreases withthe increase of P content. The effect of P cothent on 3d magnetic moment in Coatom was discussed on the basis of the electron transfer model and the change ofcoordination number of nearest-neighbour Co atom around the central Co atom.

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