31 KB476 KB30 KB200020242002Arzenšek, BorisBreskvar, BojanMarkoli, BoštjanSkobir Balantič, Danijela AnicaSpaić, SavoVodopivec, FrancVojvodič-Tuma, Jelenaštevilka:1/2letnik:368 stranistr. 25-32ISSN:1580-2949COBISSID:363359URN:URN:NBN:SI:doc-RIB5GIR3slInštitut za kovinske materiale in tehnologijeMateriali in tehnologijekonstrukcijska jeklamehanske lastnostistaranježilavostO deformacijskem staranju konstrukcijskih jekel| On strain ageing of structural steels|The effect of strain ageing as proces as well as the separate effects of 10 % of plastic strain and of 30 min. of annealing at 250 ?$^{\circ}$?C on steel properties are discussed. The deformation and the annealing separately do not change the Charpy transition temperature and the uniform elongation. The transition temperature is increased and uniform elongation decreased after strain ageing. The effect on transition temperature is virtually equal by the same steel with over 100 ppm and 2.4 ppm of carbon in solid solution in ferrite. The analysis of experimental data and theoretical calculations show that the effect of ageing can not be ascribed to the formation of discrete polyhedric particles of cementite. The explanation that the strain ageing is caused by a synergystic effect of the redistribution of carbon atoms and the structure of the plastically deformed ferrite lattice fits better to the experimental findings. This proces introduces in the ferrite lattice elastic stresses, which increase the propensity of ferrite to cleavage fractureOvrednoten je vpliv deformacijskega staranja kot celote ter ločeni vpliv 10 % plastične deformacije in 30 min. žarjenja pri 250?$^{\circ}$?C na lastnosti jekla. Deformacija in žarjenje, ločeno, ne spremenita prehodne temperature Charpyjeve žilavosti, ta se poviša po deformacijskem staranju. Učinek je podoben pri nad 100 in pri 2,4 ppm ogljika v feritu. Analiza procesov pokaže, da efekta staranja ni mogoče pripisati tvorbi diskretnih poliedričnih izločkov cementita. Verjetnejša razlaga je prerazdelitev ogljika v povezavi s strukturo plastično deformirane kristalne mreže ferita, ki olajša prelom s cepljenjem s tem, da vnese v kristalno mrežo elastične napetosti, ki povečajo občutljivost jekla za krhki lom in zmanjšajo enakomerni raztezekTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije