English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The influence of the previous state, spheroidized o r n rmalized, on the austenite formation in a steel hypoeutectoid was st udied by dilatometry in various temperatures. The process was interrupted for growi ng times. The obtained structures were analyzed by optic microscopy (including quanti t tive metallography) and by scanning electronic microscopy, which, with the dil atometric measurements, helped to identify the reaction mechanisms. In all of the studied conditions, the normalized st ruc ure has faster kinetics of austenitization than the spheroidized. The austenitization of the spheroidized material (f errite plus dispersed carbides) begins with the formation of austenite gr ains close to the carbides and with the growth of the austenite grains consuming the ferrit e and dissolving carbides, being this last one the slowest process; during growth the rel ativ quantity of carbon in the austenite is heterogeneous, tending to homogenize w ith time. The hardenability of the austenite is growing with the time. The austenitization of the normalized material (pro -eutectoid ferrite, plus fine pearlite) begins with austenite formation in t he pearlitic colonies, without detected heterogeneity of carbon distribution; when consumin g the pro-eutectoid ferrite areas the austenite begins to show heterogeneity of carbon di stribution; as final stage of the process occurred homogenization of the austenite. T h hardenability of the austenite decreases during the process of ferrite transformat ion, before the homogenization. The global kinetics, measured by dilatometry and by quantitative metallographic, is presented in the form of isother mal curves (TTT) of austenitization for the two previous studied structures.

Austenitização de aço hipoeutetóide a partir de estrutura esferoidizada e de estrutura normalizada.