The B is obviously redistributed in B steel within the whole carbonized and carbonitrided case because of the interaction between B with N and C during carbonizing and carbonitriding. The most of all behaviour of B observed in the carbonized case is the enrichment into the surface layer and the depletion from the sub-layer beneath surface, and in the earbonitrided case is the formation of abundant BN in the wide region from surface and the extension of depleted solution B into deep zone. The redistribution of B is remarkably influenced on the hardenability of the case. The carbonized case hardenability is affected not only by the carbon changed in content and influenced on B hardenability effect, but also by the B depletion in sub-layer. The abundant BN particles with solution B depletion deeply into the interior formed in carbonitrided ease is very harmful to the hardenability.

The change in internal friction and frequency associated with the bainitic transformation in a Cu-25.83Zn-3.96Al(by wt-%)alloy was conducted by a new type of instrument under isothermalholding with 0.7 Hz. Results show that the internal friction exists a maximum value Q_(max)~(-1) within the incubation period. Q_(max)~(-1) increases with the raise of the isothermal temperature, and the time up to Q_(max)~(-1) decreases with the increment of the holding temperature. The frequency value is lowest at the initial time until it reaches a stable value. While the specimen is measured under a tension of 8×10~5Pa, Q_(max)~(-1) is far larger, the time up to Q_(max)~(-1) is shorter and the initial frequency value decreases more abruptly than that under the above unloading condition. The bainitie transfromation of the alloy exists a lattice softening phenomenon somewhat similar to that in thermal elastic martensitic transformation. The prebainitic transformation within the incubation period of the bainitic transformation occurs basically with the nucleation pro cess. Based upon the theory of phase transformation and the theory of local softening mode, a rule of the change in isothermal internal friction can be interpreted through the change of the nucleation rate within the incubation period.

By using of a new type low frequency internal friction instrument controlled through a microcomputer, the change in internal friction during the course of phase transformation under continuous cooling and isothermal holding in 18CrNiWA steel is measured. Under continuous cooling, two internal friction peaks are observed around 400—430 and 320℃ (M_s) respectively. In the specimen after decarbonized with wet-hydrogen, the peak temperature changes to 600℃. The peak temperature is independent with frequency and its height increases with the decrease of frequency. Under isothermal holding the value of internal friction is always the highest at the beginning of holding and gradually decreases to a base-value with holding time in specimen whether it is decarbonized or not. Experimental results shows that the effect of frequency on the internal friction peak in bainite transformation is the same as that in martensitic transformation; within the incubation period the prebainitic transformation occurs basically with the nucleation process rather than with the diffusion of carbon; and in the initial stage of the incubation period, there exists a great number of bainitic nucleus, so the incubation period usually measured in supercooled austenite only is the time at which the grown up bainite can be observed under a specified experimental conditions.

Experimental results show that, in Fe-Ni alloys, the M_s or M_b values decrease in two steps with the decrease in quenching temperature below 950℃ with definite grain size of the parent phase. In the first step, i. e., quenching temperature around 800℃, a minimum M_s value appears, and in the second one, i.e., below 700℃ quenching, M_s decreases continueously. The burst aize of martensite transformation corresponding to the lower quenching temperatures is rather smaller than that to the higher ones. These phenomena prove to be related to the ordering of the parent phase. The observation of densely dispersed tine precipitates and superlattice dislocations by TEM comfirms the views that ordering does exist in bulk specimens and markedly affect the martensitic transformation of Fe-Ni alloys.

Based on the K-S model of the martensitic transformation, the stress field inside and outside the martensitic plate is obtained, the plastic strain and the true stress within the martensitic plate are determined and the formation of the martensitic substructure is discussed, therefore, the relationship between the yield shear strength, τ_s, and the substructure parameter, n/N, of martensitic plate may be deduced as: τ_s=G/A′[1/2(ε_(11)~*-ε_(22)~*)+(2+β_0~2)~(1/2)(cos43.5°/U+cos34.5°sin9°/V)] According to the stress and stress intensity factor resulted, the transformation cracking by quenching is quite possible.

Both empirical analysis and experimental investigation of the Nb-CuSn solidsolid diffusion couple arc shown that the Sn atoms in solid CuSn alloy diffuse into Nb lattice alone, but the diffusion of Nb atoms into CuSn alloy can be neglected. The only Nb_3Sn phase is formed with superior stability after diffusion. On the basis above mentioned, the discussion about the formation of Nb_3Sn during diffusion of solid-solid system was made. Furthermore, certain allied topics on that during solid-liquid diffusion were also interpreted briefly.

Fatigue crack propagation threshold and slow propagation near it were studied at the constant amplitude of the cyclic load ratio, R=0.5 for three-point bend specimen of the austenite stainless steel. The effect of grain size on the plastic deformation of crack tip at the threshold and at slow propagation near it were investigated using the relief method. The results show that the threshold value of crack propagation increases linearly with the square root of grain size and the rate was slower for larger grain sized material. The proportionality factors of plastic deformation zone size of crack tip and (K_(max)/σ_z)~2 for various grain size are different at the threshold. The larger the grain size, the larger is the proportionality factor. At the same time, the distinction of the plastic deformation development is the uncontinuous and unsymmetric as da/dN is from 2×10~(-8)-10(-7)mm/cyc. A dimensionless criterion of crack starting propagation, n(△K_(th)/2σ_sd~(1/2)) which is constant for various grain size was obtained after the results of the test were put in order. Its physical significance is that fatigue crack starts to propagate when the square root of the ratio of the cyclic plastic zone size and grain size equals 0.6. The metallographic and SEM observations show that the crack propagation near the threshold of austenite stainless steel proceeds on the transgranular shear mode cyclic cleavage and plasticity tear.

The influences of solution treatment and Ti content on the dissolution behaviour of β-phase in Ni-Be-Ti alloys were studied by techniques of optical microscopy, DTA and EMPA. Plots of the dissolution rate of β-phase against solution treatment parameters were made quantitatively. The dissolution process ofβ-phase in this alloy was elucidated in the light of the data obtained.

The high temperature low cyclic fatigue (LCF) behaviour of a directionally solidified Ni-base alloy DK3 has been studied under strain-controlled and stresscontrolled at 7600℃ in comparison with a conventional cast alloy K3. It was found that for both alloys, their behaviours may be characterized by the conventional stress fatigue curve. The intersections of elastic and plastic lines, so-called "transitional fatigue life", N_T, is absence for alloy DK3 and a little for K3. Under various strain and stress load, LCF life of alloy DK3 is longer than that of K3. When the stress level reduces from 980 to 785 MPa, the difference between the lives of both alloys is about 2 times; when stress level from 685 to 490 MPa, the difference increases more than 3 times.

The use of the s-regular anion sub-lattice assumption instead of the ideal anion sub-lattice one in the Whiteway, Smith and Masson (WSM) model leads to a four-parameter branched chain polymerization model for the binary silicate melts. For most slags investigated so far, three interchange energy parameters in the present model, W_(12), W_(o1) and C (C=W_(o2)-W_(o1)), could be assumed to be zero; then it becomes an one-parameter model, i.e. the WSM model. For the CaO-SiO_2 melts, the three above-mentioned parameters could be assumed to have the same value that does not equal zero. The new model is then converted into a twoparameter model. With the interchange energy parameter W_(12)/RT=-0.023 and the thermodynamical equilibrium constant K_(11)~0=0.0044 for the reaction SiO_4~(4-)+SiO_4~(4-)=Si_2O_7~(6-)+O~(2-) the new model is in better agreement with the experimental data on the activity in the CaO-SiO_2 melts at 1600℃ in the region of 0.412≤N_(SiO_2)≤0.450.

For the purpose of studying the influence of Ca on the activity coefficient of Al, f_(Al)~(Ca), in Ag, the dependence of the distribution ratio R_(Al)(=[%Al]_(Fe)/[%Al]_(Ag)) on Ca content in Ag was determined at 1600℃. The results obtained can be expressed as follows: R_(Al)=-2.91(%Ca)~2+3.51(%Ca)+3.05 and the interaction coefficient can be evaluated as lgf_(Al)~(Ca)=-0.441(%Ca)~2+0.476(%Ca) with Ca content within the range of 0 to 0.54%. The interaction parameters e_(Al)~(Ca) and e_(Ca)~(Al) are evaluated as 0.476 and 0.705 respectively. Preliminary results obtained on the distribution of Ce between Ag and Fe show that R_(Ce)(=[%Ce]_(Fe)/[%Ce]_(Ag)) is as low as 3.70×10~(-3). Besides, some thermodynamic functions are also deduced from the experimental results mentioned above.

An internal friction peak near 370℃ is observed for a Co-base superalloy Co-22Ni-22Cr-14W. This is due to the C-C pairs of the interstitial solute C atoms which make the lattice distortion in different directions under stress, and is fairly corresponding with the segregation of C atoms, the precipitation of carbide and the ductility of the alloy. The C atoms segregate continuously toward the vicinity of grain boundary, and the peak reduces continuously its own height as the prolongation of aging time. The peak will soon disappear while the carbide precipitates out. The addition of La may influence the internal friction peak as well as the microstructure and mechanical properties of the alloy The increase of its activation energy and the retardation of carbide precipitated may be caused by the increase of La content in the alloy.

The normalized and normalized plus cold-rolled structures and their effects on the formation of austenite in 0.08C-1.5Mn steel were examined by TEM. It was shown that during intercritical annealing, the austenite formation was accompanied by spheroidization of cementite in the initially normalized structure, a result attributed to the existence of more dislocation in ferrite and degenerated pearlite containing many changes in spacing and interruption in lamellar morphology in the normalized condition. The austenite nucleated not only at the cementite particles located at the triple points and faces of ferrite grain boundaries, but also at the interfaces of ferrite and cementite which was within ferrite matrix. Due to the effect of cold rolling, the lamellar cementite in the cold-rolled structure was distorted severely and even fragmented. Also, a great amount of dislocations were introduced into the ferrite matrix. These effects of the cold rolling accelerated the spheroidization of cementire and enhanced the possibility that the austenite formed within ferrite grains during intercritical annealing. The relationship between austenite formation and cementite spheroidization and the possible sites of austenite nucleation were discussed.

The effect of acicular ferrite in Widmanstatten structure on the mechanical properties of subeutectoid steel was studied. The results show that the substrueture of acicular ferrite consists of subgrains. The subgrain boundary is surrounded with dislocation tangles. The interior of subgrain is evenly distributed with the movable dislocations which are higher in density than that in cubic ferrite. The superior strength and better toughness are then obtained. It is revealed under direct observation that the cracks propagate to meet with obstacles of acicular ferrite and to change their direction forward even through or around it. Thus, it seems to be believed that the acieular ferrite in Widmanstatten structure is benefit to improve the mechanical properties of subeutectoid steel.

The stainless steel 1Cr18Ni9Ti corrodes severely in the boiling 45% MgCl_2 solution. But an improvement on strength and prolongation of rupture time under stress corrosion are obviously shown if it undergoes an application of alternating stress, saying, 20 to 39 MPa, superposing to the static stress. The smaller the static stress, the more obvious the effect is. Even the alternating stress increases up to 68 MPa, it does not shorten any more rupture time. Since the machine parts are quite difficult to operate under no mechanical vibration, it seems to be available for elongating the rupture life of which the machinery runs under corrosive medium with an additional alternating stress controlled within a narrow limit.

By means of the low temperature electrolysis with organic electrolyte and the radioassay method, either alloyed Ce in commercial cast iron and in high purity Fe-C-Si alloy or Ce in graphite was measured. The Ce in graphite is slightly higher than in neighboured matrix in most cases. With the same Ce content, more is alloyed in cast iron in comparison with steel. The eoating-autography shows that the Ce distributes uniformly in the flaky graphite, yet variously in the nodular graphite. The "exploded" graphite gets the most Ce among flaky and nodular ones. Ce is depleted from ferrite and pearlite surrounded by nodular graphite, and enriched in pearlite and ledeburite far apart from nodular graphite. Minor Ce is found in pearlite and honeycomb ledeburite which transformed by the dendrite of primary austenite, while major Ce in ledeburite of lathy cementite type. The Ce is remarkably concentrated in the last solidification zone on the eutectic transformation. It could be believed that the formation of nodular graphite mainly depends upon the anti-nodulizer, e. g. S, which is more effective than residual nodulizer or alloying contribution in the raw melted iron.

X-ray diffraction, DTA and other methods were used to determine the phase relations between native mischmetal (Mm) and MmNi_5 as well as the phase diagram of LaNi_5-PrNi_5 pseudo-binary system. The hydrogen desorption capacities and hydrogen adsorption plateau pressure of LaNi_5-PrNi_5 (CeNi_5, NdNi_5) system varied with the compositions of specimens and the hydrogen absorption properties of La-rich and Ce-rich MmNi_5 were also studied. The free energy, △Z, the enthalpy, △H, and the entropy, △S, of the hydride of La-rich MmNi_5 were estimated to be 6.14 kJ/mol H_2,-20.92 kJ/mol H_2 and-90.8 J/K.mol H_2 respectively.

The mathematical formula for the martensitic transformation from cubic phase to tetragonal, orthorhombic and monoclinic martensite was derived in the light of phenomenological theory. The computer simulation had been made of a typical thermoelastic material TiNi by advanced several possible martensitic transformation models. They are K_l=(111)_M, (111)_M (twinned crystal type Ⅰ) and η_l=[110]_M (type Ⅱ) on the TiNi(β) where the structural mode of the martensite is characterized by the lattice parameters being a=0.2889, b=0.4120, c=0.4622nm and β=96.8°; and K_l=(111)_M, (111)_M (type Ⅰ)on theTiNi(γ) where the structural mode of the martensite is characterized by the lattice parameters being a=0.2885, b=0.4622,c=0.4120nm and γ=96.8°. Both of them are capable of satisfying the requirements that the interphase interface is the plane of zero average distortion, and are found to be in agreement with the available experimental results given by the other authors.

In the light of the phenomenological theory, the crystallographic feature ofthe martensitic transformation in 10 binary and ternary Ti alloys including TiMo, Ti-Nb, Ti-Mo-Si, Ti-V-Al and Ti-6246 has been studied on the basis of the formulation and computer simulation given by the author in part Ⅰ of this article. The results indicate that the shear magnitude for the β→a″ transformation of these Ti alloys ranged from 0.03070 to 0.09551. The substructure of a″ martensite is made of the internal twins. The ratio of the twin thickness in a″ martensite of most Ti alloys is from 1 to 4. The volume change of β→a″ phase transformation in partial alloys is within 0.01. These features seem to identify the thermoelastic martensite transformation taking a crystallographic view.

Based on the common used assumptions and differential sputtering model, the equations describing sputtering process have been derived. Both concentration and depth can be calculated simultaneously. It is suitable not only for the homogeneous binary systems but also for the multicomponent systems which are not necessary to be a homogeneous one. Some possible original concentration distribution systems have been treated with those equations and showed they are workable.

An approach was made theoretically to the load spectrum for the drill rod under striking. A source programme has been written to computer the drilling load oscillogram of a striking-penetrating system. The theoretical estimation of the fatigue life of the drill rod is carried out bY analyzing the rule and constitution of the load spectrum and its influence on the surplus life of drill rod.

A new boundary condition of the vorticity on the surface of the cavity caused by an impinging gas jet has been derived. The relationship between the flow field of the liquid and the impinging jet is then established. Comparing with the previous works, the velocity distributions of the flow fields are in better agreement with the experimantal results meastared.

Camphene-1.2% cyclohexanol which freezes like metals, has been used for the investigation of crystal growth during directional solidification with continuously changing heat flow direction. The interface morphology of the columnar crystal changed according to the heat flow and this led to a change in the growth direetion of the columnar crystals. For cellular growth, the cells lay between <001> and the heat flow direction, and approached more closely to the <001> as the ratio of temperature gradient to growth rate decreased. For dendritic growth, the trunks grew in the <001> direction and did not change whatever the direction of heat flow. In contrast the sidebranches were very much affected by the heat flow direction——the sidebranches on the side against heat flow direction developed faster. The direction of columnar crystals tended to follow the heat flow direction, but different mechanism operated depending on the interface morphology.

The pole figure and inverse pole figure of the hydrostatically extruded Zr-2.5%Nb alloy tube with various Q values (the reduction ratio of wall thickness to diameter) were examined by X-ray diffration. It is resulted that the texture parameter, V_48 is related linearly to Q value. The texture gradient along the direction of tube wall thickness seems to be no appreciable. When the Q value changes from 0.2 to 2.59, the hydride is distributed into a circular direction via radial, and the corresponding texture parameter V_48 decreases from 0.53 to 0.28.The circular hydride distribution may be re-orientated under circular tensile stress after cyclic heat-treatment. The threshold of the stress re-orientaton of hydrideis rather high for tube with radial basal pole texture.

The precise measurement of electrical resistivity of Karma alloy in the temperature range from 70 to 440 K was conducted in the further development of an adiabatic calorimeter. The minimum and maximum resistivity was obtained as 133.340 and 133.906 μΩcm respectively. A maximum near 340 K on the plot of temperature dependence upon resistivity is an anomaly that seems to be neceessary for any further study.