An Alternative Approach to the Fracture Toughness of Dual Phase Steels

Abstract

Èññëåäóåòñÿ âëèÿíèå ìîðôîëîãèè ñòðóêòóðû ôåððèòà è åãî îáúåìíîãî ñîäåðaeàíèÿ íà ìåõàíè÷åñêèå ñâîéñòâà è âÿçêîñòü ðàçðóøåíèÿ äâóõôàçíûõ ñòàëåé. Äëÿ îïðåäåëåíèÿ çíà÷åíèé âÿçêîñòè ðàçðóøåíèÿ èñïîëüçîâàëè íå ñòàíäàðòíûé, à àëüòåðíàòèâíûé ïîäõîä. Ñòàëè ïîäâåðãàëè ãîìîãåíèçèðóþùåé òåðìîîáðàáîòêå. Ïóòåì ïîëíîãî îòaeèãà èëè çàêàëêè ñòàëåé èç àóñòåíèòíîãî ñîñòîÿíèÿ äî ïðèìåíåíèÿ äîêðèòè÷åñêîãî îòaeèãà â àóñòåíèòíîé îáëàñòè ïîëó÷åíû äâå ðàçëè÷íûå èñõîäíûå ìèêðîñòðóêòóðû. Ïîëó÷åíû äâóõôàçíûå ñòàëè ñ äâóìÿ òèïàìè ìîðôîëîãèè (êðóïíî-è ìåëêîçåðíèñòàÿ) ñ 40-, 20-è 10%-íûì îáúåìíûì ñîäåðaeàíèåì ôåððèòà â çàâèñèìîñòè îò èñõîäíîé ìèêðîñòðóêòóðû. Îòïóùåííûå îáðàçöû ñ 10%-íûì îáúåìíûì ñîäåðaeàíèåì ôåððèòà èìåëè áîëåå âûñîêèå çíà÷åíèÿ âÿçêîñòè ðàçðóøåíèÿ ïî ñðàâíåíèþ ñ òàêîâûìè äðóãèõ îáðàçöîâ èç ýòèõ ñòàëåé.

Fatigue Crack Growth and Fracture Toughness in a Dual Phase Steel: Effect of Increasing Martensite Volume Fraction

“…These constraints generate that in the dual-phase steels has not been widely studied. In general, some researches show results from alternative methods like tensile tests [13], impact tests [14], use of special specimens [15], or more recently the use of new methods, like the essential work of fracture tests [16], [17] instead of the one specified by ASTM 1820 [18] standard, in order to decrease the number of samples and reduce the cost of the test. Most of these researches are focused on the influence of microstructure on the mechanical properties.…”

Effect of the intermediate quenching on fracture toughness of ferrite-martensite dual phase steels

“…Shengci Li et al [23] used the compact tension (CT) specimen to evaluate the fracture behavior of the DP780 dual phase steel. Also the effect of loading [24], elevated temperature [25], inclusions [26], ferrite morphology and of ferrite volume fraction [27] of the ferritic/martensitic stainless steel was studied by the various authors. From the results it is recommended that the volume fraction of the produced ferrite/martensite influence the fracture toughness of the material.…”