Phase transformation in austempered ductile iron by microjet impact

Geometry, mechanical and ballistic properties of ADI material perforated plates

“…to the values before the ballistic testing. The increase in hardness near the fracture surface can be attributed to two effects [29][30][31][32]: (1) work-hardening and (2) martensite formation, as confirmed by the microstructural and fracture analyses. This observation is similar to the findings in [28], where an elevated hardness was found to be caused by work-hardening and microstructural changes induced by deformation, caused by ballistic impact in Cr-Ni-Mo weld metal zones.…”

“…In this case, SITRAM effect, that is, the martensite formation does not contribute to the ballistic performance of the ADI-400 perforated plates. This is in contrast to the effect of the martensite during cavitation [6,29] and wear [33], which is beneficial for the increase in the performance of the specimens austempered at higher temperatures with an elevated amount of bulk retained low-carbon metastable austenite. However, in the literature [6,29,33], martensite is formed by stress-assisted phenomenon (SATRAM) and it is not subjected to massive, fast-plastic deformation.…”

“…7b. The martensite occurs in the area of the intensive plastic deformation in ADI-400 and forms through the strain induced phase transformation of retained austenite into martensite (SITRAM) [29][30][31][32]. According to Fig.…”

Influence of cooling rate on the microstructure and properties of a new wear resistant carbidic austempered ductile iron (CADI)

“…It was evident from this table that as the water content increase, the hardness of the samples increase, and the impact toughness decrease. It may be depended on the growth of ferrite, carbon diffuses to austenite and forms carbon enriched austenite [20]. Because the ferrite (low-carbon phase) transformation makes more carbon atoms diffuse into austenite and makes austenite contain more carbon content.…”

Effects of Inclusion Particles on the Microstructure and Mechanical Properties of High Strength Austempered Ductile Iron

“…After the interaction persists a period of time, blocky austenite may transform into martensite and/or carbon may diffuse and precipitates to form carbide and ferrite lath within blocky austenite. Wu et al 20) used ultrasonic vibration to induce micro-jet impacting the ADI specimens. For unalloyed ADIs, martensitic transformation occurred in the initial period of impact.…”