23 research outputs found
Study of the Eutectoid Transformation in Nodular Cast Irons in Relation to Solidification Microsegregation
Eutectoid transformation in cast irons may proceed in the stable or the metastable systems giving ferrite and graphite for the former and pearlite for the latter. The present work demonstrates that composition profiles across ferrite/pearlite boundaries are smooth and similar to those issued from the solidification step. No trace of long-range diffusion of substitutional solutes due to austenite decomposition could be observed. In turn, this ascertains that both stable and metastable transformations proceed with the product matrixβeither ferrite opearliteβinheriting the parent austenite content in substitutional solutes. This result sustains a physical model for eutectoid transformation based on the so-called local para-equilibrium which is commonly used for describing solid-state transformation in steels
The effects of metallurgical process variables on the properties of austempered ductile irons
Effect of austenitising conditions on the impact properties of an alloyed austempered ductile iron of initially pearlitic matrix structure
Effect of austenitising temperature on tensile properties of CuβNi austempered ductile iron
Fatigue lifetime of ADI from ultimate tensile strength to permanent fatigue limit
S β N curve of austempered ductile iron was obtained in the range of lifetime including low cycle fatigue domain and high cycle fatigue domain up to 108 cycles. Ultimate tensile strength is used as a limiting value of the curve. Symmetric push-pull fatigue and tensile tests were performed at room temperature on isothermally treated nodular cast iron alloyed with copper and nickel having positive impact on mechanical, technological and fatigue properties of austempered ductile iron. Suitable functions for the fit of experimentally determined points were tested and their parameters were calculated. The best results were obtained using the Palmgren function and the function introduced by Kohout and Vechet. Since the loading frequency in high-cycle region is two orders higher than in low-cycle region, the effect of loading cycle frequency on fatigue behavior of the studied material is also studied. A possibility of discontinuity of experimental data between low-cycle and high-cycle regions is discussed.ΠΠΎΠ»ΡΡΠ΅Π½Π° ΠΊΡΠΈΠ²Π°Ρ ΡΡΡΠ°Π»ΠΎΡΡΠΈ Π°ΡΡΡΠ΅Π½ΠΈΡΠ½ΠΎ-ΠΎΡΠΏΡΡΠ΅Π½Π½ΠΎΠ³ΠΎ ΠΊΠΎΠ²ΠΊΠΎΠ³ΠΎ ΡΡΠ³ΡΠ½Π° (ADI) Π² Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½Π΅ Π΄ΠΎΠ»Π³ΠΎΠ²Π΅ΡΠ½ΠΎΡΡΠΈ, Π²ΠΊΠ»ΡΡΠ°Ρ ΠΎΠ±Π»Π°ΡΡΠΈ ΠΌΠ°Π»ΠΎΡΠΈΠΊΠ»ΠΎΠ²ΠΎΠΉ ΠΈ ΠΌΠ½ΠΎΠ³ΠΎΡΠΈΠΊΠ»ΠΎΠ²ΠΎΠΉ ΡΡΡΠ°Π»ΠΎΡΡΠΈ Π΄ΠΎ 108 ΡΠΈΠΊΠ»ΠΎΠ². Π ΠΊΠ°ΡΠ΅ΡΡΠ²Π΅ ΠΏΡΠ΅Π΄Π΅Π»ΡΠ½ΠΎΠ³ΠΎ Π·Π½Π°ΡΠ΅Π½ΠΈΡ ΡΠΊΠ°Π·Π°Π½Π½ΠΎΠΉ ΠΊΡΠΈΠ²ΠΎΠΉ ΠΈΡΠΏΠΎΠ»ΡΠ·ΡΠ΅ΡΡΡ ΠΏΡΠ΅Π΄Π΅Π» ΠΏΡΠΎΡΠ½ΠΎΡΡΠΈ ΠΏΡΠΈ ΡΠ°ΡΡΡΠΆΠ΅Π½ΠΈΠΈ. ΠΡΠΎΠ²Π΅Π΄Π΅Π½Ρ ΠΈΡΠΏΡΡΠ°Π½ΠΈΡ Π½Π° ΡΡΡΠ°Π»ΠΎΡΡΡ ΠΏΡΠΈ ΡΠΈΠΌΠΌΠ΅ΡΡΠΈΡΠ½ΠΎΠΌ ΡΠ°ΡΡΡΠΆΠ΅Π½ΠΈΠΈ-ΡΠΆΠ°ΡΠΈΠΈ ΠΈ Π½Π° ΡΠ°ΡΡΡΠΆΠ΅Π½ΠΈΠ΅ ΠΏΡΠΈ ΠΊΠΎΠΌΠ½Π°ΡΠ½ΠΎΠΉ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ΅ ΠΈΠ·ΠΎΡΠ΅ΡΠΌΠΈΡΠ΅ΡΠΊΠΈ ΡΠ΅ΡΠΌΠΎΠΎΠ±ΡΠ°Π±ΠΎΡΠ°Π½Π½ΠΎΠ³ΠΎ ΡΡΠ³ΡΠ½Π° Ρ ΡΠ°ΡΠΎΠ²ΠΈΠ΄Π½ΡΠΌ Π³ΡΠ°ΡΠΈΡΠΎΠΌ, Ρ Π΄ΠΎΠ±Π°Π²ΠΊΠ°ΠΌΠΈ ΠΌΠ΅Π΄ΠΈ ΠΈ Π½ΠΈΠΊΠ΅Π»Ρ, ΠΊΠΎΡΠΎΡΡΠ΅ ΠΎΠΊΠ°Π·ΡΠ²Π°ΡΡ ΠΏΠΎΠ»ΠΎΠΆΠΈΡΠ΅Π»ΡΠ½ΠΎΠ΅ Π²Π»ΠΈΡΠ½ΠΈΠ΅ Π½Π° ΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΠ΅, ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΈ ΡΡΡΠ°Π»ΠΎΡΡΠ½ΡΠ΅ ΡΠ²ΠΎΠΉΡΡΠ²Π° ADI. ΠΡΡΡΠ΅ΡΡΠ²Π»Π΅Π½Π° ΠΏΡΠΎΠ²Π΅ΡΠΊΠ° ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²ΡΡΡΠΈΡ
ΡΡΠ½ΠΊΡΠΈΠΉ Π΄Π»Ρ ΠΎΠΏΠΈΡΠ°Π½ΠΈΡ ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΠΎ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Π½ΡΡ
ΡΠΎΡΠ΅ΠΊ; Π²ΡΠΏΠΎΠ»Π½Π΅Π½ ΡΠ°ΡΡΠ΅Ρ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ² ΡΠΊΠ°Π·Π°Π½Π½ΡΡ
ΡΡΠ½ΠΊΡΠΈΠΉ. ΠΠ°ΠΈΠ»ΡΡΡΠΈΠ΅ ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΡ ΠΏΠΎΠ»ΡΡΠ΅Π½Ρ ΠΏΡΠΈ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΠΈ ΡΡΠ½ΠΊΡΠΈΠΈ ΠΠ°Π»ΡΠΌΠ³ΡΠ΅Π½Π° ΠΈ ΡΡΠ½ΠΊΡΠΈΠΈ, ΠΏΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½Π½ΠΎΠΉ ΠΠΎΠ³ΡΡΠΎΠΌ ΠΈ ΠΠ΅ΡΠ΅ΡΠΎΠΌ. ΠΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΎ ΡΠ°ΠΊΠΆΠ΅ Π²Π»ΠΈΡΠ½ΠΈΠ΅ ΡΠ°ΡΡΠΎΡΡ ΡΠΈΠΊΠ»ΠΎΠ² Π½Π°Π³ΡΡΠΆΠ΅Π½ΠΈΡ Π½Π° ΡΡΡΠ°Π»ΠΎΡΡΠ½ΠΎΠ΅ ΠΏΠΎΠ²Π΅Π΄Π΅Π½ΠΈΠ΅ ΡΠ°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°Π΅ΠΌΠΎΠ³ΠΎ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π° Ρ ΡΡΠ΅ΡΠΎΠΌ ΡΠΎΠ³ΠΎ, ΡΡΠΎ ΡΠ°ΡΡΠΎΡΠ° Π½Π°Π³ΡΡΠΆΠ΅Π½ΠΈΡ Π² ΠΌΠ½ΠΎΠ³ΠΎΡΠΈΠΊΠ»ΠΎΠ²ΠΎΠΉ ΠΎΠ±Π»Π°ΡΡΠΈ Π½Π° Π΄Π²Π° ΠΏΠΎΡΡΠ΄ΠΊΠ° ΠΏΡΠ΅Π²ΡΡΠ°Π΅Ρ ΡΠ°ΡΡΠΎΡΡ Π½Π°Π³ΡΡΠΆΠ΅Π½ΠΈΡ Π² ΠΌΠ°Π»ΠΎΡΠΈΠΊΠ»ΠΎΠ²ΠΎΠΉ ΠΎΠ±Π»Π°ΡΡΠΈ. Π Π°ΡΡΠΌΠΎΡΡΠ΅Π½Π° ΡΠ°ΠΊΠΆΠ΅ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΡ ΠΎΡΡΡΡΡΡΠ²ΠΈΡ Π½Π΅ΠΏΡΠ΅ΡΡΠ²Π½ΠΎΡΡΠΈ Π² ΡΠΊΡΠΏΠ΅ΡΠΈΠΌΠ΅Π½ΡΠ°Π»ΡΠ½ΡΡ
Π΄Π°Π½Π½ΡΡ
Π½Π° ΡΡΠ°ΡΡΠΊΠ΅ ΠΌΠ΅ΠΆΠ΄Ρ ΠΌΠ°Π»ΠΎΡΠΈΠΊΠ»ΠΎΠ²ΠΎΠΉ ΠΈ ΠΌΠ½ΠΎΠ³ΠΎΡΠΈΠΊΠ»ΠΎΠ²ΠΎΠΉ ΠΎΠ±Π»Π°ΡΡΡΠΌΠΈ