ISSN 0412-1961
CN 21-1139/TG
Started in 1956

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    , Volume 13 Issue z1 Previous Issue    Next Issue
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    X-RAY STRESS MEASUREMENT TECHNIQUE BY SIDE INCLINATION METHOD WITHOUT -η INCLINING INCIDENT ANGLE
    Res. Gp. of Fatigue; Institute of Metal Research
    Acta Metall Sin, 1977, 13 (z1): 1-22. 
    Abstract   PDF (1454KB) ( 437 )
    The stress calculation formulas for side inclination method without -η in-clining incident angle have been deduced based on its special geometrical rela-tions, the results obtained are as follow:2θ=αsin~2ψ_0+b sin ψ_0+c, σ_x= (K sec~2η_0)α, T_(xy)= (-K csc 2η_0)b After measuring a set of 2θ values corresponding to the incident angles ψ_0by this method, the coefficients α and b in the parabola equations can becalculated by ±ψ_0 linear method or ±ψ_0 Parabola method as presented in thetext, and normal stress σ_x in the measurement direction and shearing stressT_(xy) in the plane to which σ_x applied can thus be obtained. Results of erroranalysis show that the stress calculation formulas and the above ±ψ_0 methodscan satisfy requirements for either engineering or laboratory practice. As σ_2 and T_(xy) can be obtained simultaneously by a single measurement withthis method, so the state of stress at any point on the surface of the object canbe determined by measuring only in two directions at this point. If the 2θ values measured by side inclination method without -η incliningincident angle were treated by the stress calculation formulas of the convention-al method or the side inclination method with -η inclining incident angle, alarge systematic error may often be introduced, its magnitude being decidedmainly by the real values of σ_x, T_(xy) and η_0. The above derived stress calculation formulas are substantiated by experimentalresults.
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    A COPPER-CONTATAINING LOW ALLOY STEEL RAIL OF GRADE 45 Kg/M
    Research Institute of Wuhan Iron and Steel Company
    Acta Metall Sin, 1977, 13 (z1): 23-152. 
    Abstract   PDF (3579KB) ( 407 )
    With a view to utilizing certain iron ores contaminating with copper, a cop-per-containing low alloy rail steel (WP2) has been developed by Wuhan Ironand Steel Company. Such a rail steel containing 1% Si has been adopted forour own design of rails of grade 45 kg/m. It possesses high strength (σ_b≥92kg/mm~2) and hardness (on rail top≥280HB) with satisfactory toughness andplasticity as well as good resistance to wear and to atmospheric corrosion. Thiskind of rail may be used without quenching. Long-time railway running testsshowed that such a rail (WP2) performs well against wear and impact, exhibi-ting little corrosion at rail waist and bottom. It has been used not only inChinese railwavs but also in the Tanzania-Zambia railway in Africa.
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    A NEWER SLIME CONCENTRATOR "THE VIBRATING-SHAKING VANNER"
    Res. GP. of Ore Dressing Equipment; Kwangtung Institute of Non-Ferrous Metal Research
    Acta Metall Sin, 1977, 13 (z1): 35-45. 
    Abstract   PDF (848KB) ( 504 )
    Combining the effective actions of vanning, tabling and heavy mineral pan-ning, a new type slime coneentrator, so called "the vibrating-shaking vanner",has been developed. This concentrator is characterized by concentration ofheavy mineral grains in sub-sieve range. Its remarkable performance is of higherrecovery, as well as of higher ratio of concentration. The lower limit of thegrain size which can be effectively concentrated is about twenty microns. In thecase of concentrating the slime of tungsten, tin or niobium-tantalum ores, com-parative tests on the vibrating-shaking vanner against common table and vannergenerally gave better results, especially for grain size down to forty microns.Furthermore, this vanner can also be applied for table-flotation of slime concen-trates in order to separate sulphides or to recover heavy minerals from flotationconcentrates contaminating with sulphides. Long-time service has proved that theabove vanner gives good performance and its application in metallurgical industryis ever-increasing.
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    J(T_0γ_0/X_1X_2) AND THEORETICAL AND EXPERIMENTAL PROOF OF PATH-DEPENDENCE OF J-INTEGRAL FOR PLASTIC FRACTURE
    Liu Shu-yi University of Science and Technology of China
    Acta Metall Sin, 1977, 13 (z1): 46-56. 
    Abstract   PDF (644KB) ( 441 )
    In this work, Rice's J-integral was re-examined both mathematically andphysically. J and the work density pfaffian δW areIt follows that the n. and s. condition for J to be path-independent is that in simply connected region:
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    ON THE CRITERION FOR CRACK EXTENSION
    Chen Chih
    Acta Metall Sin, 1977, 13 (z1): 57-153. 
    Abstract   PDF (1937KB) ( 724 )
    Based on the inevitable blunting of the crack-tip and the finiteness of stressand strain, it is shown that the basic criterion for crack extension is either themaximum shear stress criterion (for ductile fracture) or the maximum principalstress criterion (for cleavage fracture) after analyzing three series of experimentaldatum. Critical relations can be deduced under specific conditions. In the caseof plane strain and small scale yielding, this critical relation is just the well-known K_I=K_(Ic)=material constant; whereas, in the case of plane stress andsmall scale yielding, the critical relation deduced is K_c=(π/8kσ_Fε_F~2BE)~(1/2). Factorseffecting K_(Ic) were also discussed.
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    THE APPLICATION OF MINICOMPUTER IN ELECTRON DIFFRACTION STUDIES Ⅲ. INDEXING OF ELECTRON DIFFRACTION PATTERNS OF SINGLE CRYSTALS WITH UNKNOWN LATTICES
    Electron-Microscopy Lab.; Institute of Metal Research
    Acta Metall Sin, 1977, 13 (z1): 73-79. 
    Abstract   PDF (525KB) ( 508 )
    A computer program in FORTRAN to aid indexing of electron diffraction pat-tOrns of single crystuls with unkown lattices has been written. By tilting thecrystalline specimen two electron diffraction patterns are obtained, from whichthree diffraction 'pots are chosen corresponding to three base vectors of a pri-mitive triclinic reciprocal cell. The lengths of reciprocal lattice vectors with4 References | Related Articles | Metrics
    EFFECTS OF ALUMINIUM ON COMMERCIAL GRAIN-ORIENTED 3% Si-IRON WITH MnS AS THE MAIN SECOND PHASE
    Res. GP. of Silicon-Iron; Peking Institute of Iron and Steel Research
    Acta Metall Sin, 1977, 13 (z1): 80-161. 
    Abstract   PDF (8495KB) ( 469 )
    The effects of aluminium on the hot-rolling structure and texture, primaryrecrystallization, secondary recrystallization and magnetic properties of commercialgrain-oriented 3% Si-iron with MnS as the main second phase have been inve-stigated. It was found that within the range of 0.007 to 0.040% aluminiumcontent (acid soluble) in silicon iron, the magnetic induction of the product,B_(10), could reach 18000 G until the temperature of the slab reheating prior tohot rolling was about 1250℃. With soluble aluminium contents outside thisrange, the value of B(10) was sharply decreased as the slab reheating temperaturewas lowered. The deformation structures and textures of the hot rolled sheetsin mid-thickness layer varied with the variations of the soluble aluminium con-tents in silicon iron as shown by the corresponding changes of structures afterprimary and secondary recrystallization. Although the role of aluminium playedin the silicon iron may be traced back prior to the hot rolling, it appears thataluminium mainly influences the deformation, dynamic precipitation of the secondphase and dynamic recrystallization processes of the material during hot rolling.Further studies are necessary to clarify the exact mechanism involved in theeffect of aluminium in grain-oriented 3% Si-iron.
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    QUANTITATIVE DETERMINAMON OF GRAIN ORIENTATION AND TEXTURE BY ETCH-FIGURE METHOD
    Luo Yang
    Acta Metall Sin, 1977, 13 (z1): 93-108. 
    Abstract   PDF (1038KB) ( 642 )
    The etch-figure method which is useful for determining the crystal orienta-tions of grain-oriented silicon iron with sufficient accuracy for industrial practicehas been examined. In this paper an attempt has been made to measure theorientations of the secondary recrystallized grains by means of this method, thedistribution and the changes of the textures in the longitudinal section alongcertain depths being observed. The preparation of the specimens has been described and a method of de-termining the grain orientations by using the geometrical parameters of theetch-figures is given. In order to determine the orientations, three angular para-meters are used: angle θ between the rolling direction and the projection of[001] on the surface of sheet; angle φ between [001] and the surface of sheet,and angle ω between [110] and the sheet surface. The geometrical parametersof both triangular and rectangular etch-figures produced by {100} -attack asfunction of φ and ω have been deduced. For practical uses in the orientationdetermination, the relationship between the etch-figure parameters and the cor-responding φ and ω are listed in tables. With known values of θ, φ and ω, the{100} pole figures can be drawn to show the degree of misorientation of thematerial.
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    AN INVESTIGATION OF CERTAIN HIGH CARBON CHROMIUM BEARING STEEL INGOTS
    Research Institute of Tayeh Steel Works
    Acta Metall Sin, 1977, 13 (z1): 109-172. 
    Abstract   PDF (10258KB) ( 486 )
    Nine high carbon chromium bearing steel ingots melted and teemed bydifferent processes have been sectioned longitudinally and their macrostructureincluding distribution of non-metallic inclusions and carbides as well as gascontent, etc. have been examined. Ingots made by electroslage refining and so-lidifying in water cooling crystallizer showed better quality than those made bythe conventional process, especially for slabs or ingots with smaller cross-sections. High temperature diffusion annealing treatments promote the refinementof the macrostructure of ingots. Vacuum melting and teeming are very effectivefor the improvement of the quality of ingots.
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    AN INVESTIGATION OF DETERMINING J_(Ic) AND J_(Iscc) BY THE CANTILEVER BEAM METHOD
    Res. GP. of Fracture; Institute of Metal Research
    Acta Metall Sin, 1977, 13 (z1): 122-128. 
    Abstract   PDF (535KB) ( 375 )
    The delayed failure of a steel structure occurs as a result of the stress cor-rosion cracking and hydrogen embrittlement and similar brittle fracture mayalso happen at the site of the fatigue or weld cracks. The prediction of suchfailures has attracted the attention of many investigators. The concepts of J-integral in elastic-plastic mechanics have been introducedto investigate the delayed failure, and the method which can determine thecritical values of J-integral J_(Ic) and the threshold values of stress corrosioncracking J_(Iscc) with a cantilever beam bend specimen having a fatigue crackintroduced artificially has been proposed. The J_(Ic) and J_(Iscc) values for 40CrNiMosteel specimens in a solution of hydrogen sulphide have been determined. Sucha method has been examined: (1) by comparing the J(Ic) values with those obtain-ed from the three-point bend method; (2) by comparing the stress intensityfactor K_I with those which can be determined directly by linear elastic fracturemechanics. Based on the above results, the characteristics of the cantilever beammethod has been discussed.
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    SOME PROBLEMS CONCERNING THE APPLICATION OF COLD EXTRUSION
    The Forging and Stamping Faculty; Shanghai Chiaotung University
    Acta Metall Sin, 1977, 13 (z1): 129-176. 
    Abstract   PDF (4794KB) ( 578 )
    In China, the application of cold extrusion has been very rapid. Severalkinds of hard metal has been successfully cold-extruded into parts of complicatedshapes. Evidently, the technology of cold extrusion will play an ever-increasingimportant role in our socialist construction. During cold extrusion, the die exerts a high pressure on the material to beextruded and force it to deform whereas the material exerts a reaction on thedie to resist it being deformed. Deformation and resistance against deformationare two contradictory aspects which determine the nature of the process of coldextrusion from beginning to end. However, attention must be drawn to thetransformation of the contradiction. For example, the difference of the flowingrates of metallic particles usually becomes the principal aspect of the contradic-tion when pure aluminium or unsymmetrical steel parts to be slightly deformedare cold-extruded. Workers in China have made contributions to the raising of the allowabledeformation extent, In their actual productions, extrusion pressure may reach,under some circumstances, as high as 300 kg/mm~2, under which, punches canstill be used 50, 000 times and dies 200, 000 times before they are worn out. Based on our experiences gained in actual production, and on the theory ofconcentration of stresses, the principle of "dividing dies before cracking" hasbeen adopted in designing dies, which may considerably prolong their effective life. This paper describes the combined technology of extrusion-upsetting in coldextrusion and the combined extrusion of stainless steel. It seems that the correctchoice of substitute materials suitable to the characteristics of cold extrusioncould make the cold extrusion more promising in its application than ever before.
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    EVALUATION OF BRITTLENESS OF THE NITRIDING COATING IN SOME STEEL BY ACOUSTIC EMISSION TECHNIQUE
    "Three-in-One" Res. Gp. of Peking Institute of Iron and Steel Technology; Research Institute of Peking Machine Tools Works and Institute of Metal Research
    Acta Metall Sin, 1977, 13 (z1): 139-144. 
    Abstract   PDF (427KB) ( 386 )
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    IDENTIFICATION OF CERTAIN CELLULAR PRECIPITATE FROM IRON BASE AUSAGING ALLOY 25Ni-15Cr-2Ti-Al
    Yeh Li Tayeh Steel Works
    Acta Metall Sin, 1977, 13 (z1): 145-178. 
    Abstract   PDF (1082KB) ( 455 )
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