Scale Levels of the Structure–Phase States and Fatigue Life of a Rail Steel after Electron-Beam Treatment

Abstract

Îòòèñêè äîñòóïíû íåïîñðåäñòâåííî îò èçäàòåëÿ Ôîòîêîïèðîâàíèå ðàçðåøåíî òîëüêî â ñîîòâåòñòâèè ñ ëèöåíçèåé 2013 ÈÌÔ (Èíñòèòóò ìåòàëëîôèçèêè èì. Ã. Â. Êóðäþìîâà ÍÀÍ Óêðàèíû) Íàïå÷àòàíî â Óêðàèíå.

Fractography of the fatigue fracture surface of silumin irradiated by high-intensity pulsed electron beam

“…Fatigue cracks originate usually in the surface layer of a part [2]. A highly effective method of surface modification of parts and, increase of their fatigue life [3][4][5] consequently, is a material treatment by intensity pulsed electron beam allowed to modify the structure of the surface layer of tens of micrometers in thickness, turning it into a multi-modal structural-phase state and almost without changing the structural-phase state of the main volume of the alloy. [6][7][8][9][10].…”

Increase of a Fatigue Life of a Silumin by Electron-Beam Processing

“…Показано, что преимуществен-ным местом формирования концентраторов напряжений в облу-чённой электронным пучком стали является граница раздела слоя высокоскоростной кристаллизации и слоя термического влияния (дно ванны расплава). Установлено, что увеличение усталостной долговечности стали, облучённой электронным пуч-ком, обусловлено формированием игольчатого профиля границы раздела, приводящего к диспергированию концентраторов напряжений и способствующего более однородному пластическо-му течению в подложке [35][36][37][38][39][40].…”

Structural evolution of silumin treated with a high-intensity pulse electron beam and subsequent fatigue loading up to failure

“…For 20Kh13 and 08Kh18N10T steels, the main factors are refining the grain and subgrain structure, along with dissolving the carbide phase par ticles in the surface layer [4][5][6][7][8][9][10]. The preferential site for the formation of stress concentrators in rail steel [11][12][13] irradiated with an electron beam is the inter face between the high speed crystallization layer and the thermal effect layer (the melt bath bottom). It has been established that the longer fatigue life of steel irradiated with an electron beam is due to the forma tion of a needle like interface profile, which disperses the stress concentrators and promotes a more uniform plastic flow in the substrate.…”