Thermal fatigue resistance of gray cast iron

Thermal fatigue resistance of gray cast iron

pztrticles of the tool material at the tool-chip interface was made by csamining the machined chips by S-ray diffraction, spectrographic anatvsis, ele...

137KB Sizes 0 Downloads 25 Views

pztrticles of the tool material at the tool-chip interface was made by csamining the machined chips by S-ray diffraction, spectrographic anatvsis, electron-microprobeanalysis and activatibn analysis methods. The cocfficicnt of friction and tool temperatures for different tool-work pairs were measured. The interface reactions were examined by optical microscopy- and microprobe analysis. .2 thcorctical model of flank wear was developed to estimate the amount and rate of wear. Comparison of experimental and theoretical results were made to verify the validity of the model for practical apphcations.

cracks was found to be faster in air than m the solution in which they were formed then the role of cnvironmcnt in corrosion fatigue is mainly facilitating iatigue crack nucleation, .tt stress levels belo~v the dry fatigue Iimit. a linear relationship exists bctacen fatigue cycling spcetl and the numb-r of cycles for both crack initiation and propagation, It is therefore possible to represent both crack initiation and propagation stages bv a time and number of fatigue cycles. Electricat conductivity of the solution is an important factor influencing corrosion fatigue endurance.

Thermal Fatigue Resistance of Gray Cast Iron. ASl‘X J. rl~alruials, 4 (4) IV. Rostokei, (1969) 909-923; 9 figs., 6 tables, 8 refs. .\ study of the metallurgical factors which influcncc the thermal fatigue resistance of gray cast irons. Large differences in resistance to cracking can exist. The most fatigueresistant structure is one produced by severe chilling combined with a high-suIphur and high-carbon equivalent melt.

Structure and Wear Properties of Thin FiIms of Electtoless Plated Co-P on Flexible Substrates. .\. ~%mendola, G. I%‘. Brock and E. Trewieso, ~~~~~~jCu~~~~2 E%g., 26 (J) (1970) 2. L--L j ; 5 figs., 3 refs. ‘1 study of the influence of phosphorus on the structure and wear of electroless-plated cobalt thin films. Surface topography depends on the phosphorus content of the films whilst ~vcar resistance. as measured by a ball abrasion type test, is dependent on the crystallographic orientation of the cobalt in the films.

Explosive Forming and Hardening of Metals. I%. G. Lozinskii and P. 0. Pashkov, IZussiarz Eng. J., #y (7) (1969) 73-75; 7 figs., I table, 6 refs. (Transl. by P.E.R.A. of Gt. Britain of [‘e&z. Mnschimstv., 49 (7) (1969) 63--68.) The paper deals with two of the most promising applications of the momentary impact-force effect and high compressive forces, resulting from the rapid combustion of an explosive material; the manufacture of new, sheet-metal sandlvich materials and the hardening of metals. Corrosion-resistant Low-alloy Steels : a Review with Particular Reference to Atmospheric Conditions in the United Kingdom. I<. A. Chandler and M. B. Kilcullen, Brii. Oovvosion J., 5 (I) (1970) 24-32; 3 figs., I table, 68 refs. The literature on the effects of small alloy additions to mild steel is reviewed. Papers dealing with the effect of design on performance, the painting of low-alloy steels and the theoretical background of their enhanced corrosion resistance are discussed. Besides the rcfcrenccs, an extensive supplementary bibliography is included. Corrosion Fatigue in High-carbon Steel. V. Rollens and E. Lardner. Byit. Covv~sion J., 5 (I) (1970) 33-40; I I figs., 7 tables, 6 refs. ZL study of the initiation and propagation of corrosion fatigue cracks in I y, C I l;Cr steel, subjected to a range of stresses and cycling speeds in chloride media. The corrosion fatigue process can be divided into a number of stages listed and the propagation of fatigue Wear, 26 (1970) 151-163

Development and Application of High Matrix Strength Aluminium-Boron. J. II. Forest a.nd J. L. Christian, Met& E‘N~. (&rt., IO (I) (1970) r-h; 9 figs., 4 tables, 6 refs. Practical methods of increasing both transverse tensile strength and matrix shear strength are described. Thermal treatments can essentially double the shear strength. The addition of transverse steel wires can increase the cross tension strength by a factor of 24. In some cases fabrication is simplified by eliminating doublers of isotropic material. The practicality and potcntial of the composites have been demonstrated. A Study of the Growth Mechanism of Lenticular Carbides in Cyclically Stressed 52100 Steel. S. Borgesc, JOLT, 92 Ser. F, (I) (1970) j+#; 9 figs., 12 rcfs. A transmission electron microscopical study of the deformation bands formed by cyclic stressing of gzroo steel inner races due to rolling contact. The deformation bands are regions where carbides have dissolved and a well-developed cell structure formed. Some are bordeted by lenticular-shaped carbides. If these form, the deformation regions arc free of excess carbon due to their nucleation and growth. If no lenticular carbides form, the deformation bands are supersaturated xvith carbon.