.ALPHA.+.GAMMA. and .GAMMA. Phases Annealing in Ultra Low-carbon Sheet Steels.

Reconstruction of the Three-dimensional Ferrite–austenite Microstructure and Crystallographic Analysis in the Early Stage of Reverse Phase Transformation in an Fe–Mn–C Alloy

“…The ingot was hot-rolled to 2 mm in thickness and cooled to 710°C by water spray; this was followed by furnace cooling to room temperature with a cooling rate of 20°C/h. The plate was then cold-rolled to 1 mm in thickness, and test pieces were cut from the middle part of the plate with dimensions of 200 × 10 × 1 mm 3 . After that, heat treatment was performed between 710 and 730°C with a heating rate of 5°C/s, and the test pieces were immediately quenched from the set temperature at a rate of faster than 1 000°C/s using a high-pressure water spray system.…”

“…The variant selection of austenite during reverse transformation has been discussed in the literatures and several models have been proposed. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Tomida et al proposed the variant selection model to predict the texture change in α→γ transformation based on the orientation relationships at multiple interfaces with different ferrite grains. 9,10) In these studies, the variant of austenite is assumed to be selected to simultaneously satisfy the Kurdjumov-Sachs (K-S) relationship 20) with one ferrite grain and an orientation relationship near the K-S relationship with about 10° of the tolerance angle with other adjoining ferrite grains.…”

“…For example, ferrite-to-austenite transformation occurring in an intercritical annealing range is known to indicate the memory effect. [3][4][5][6] There must be a rule that determines austenite orientation in relation to the initial ferrite texture. The variant selection of austenite during reverse transformation has been discussed in the literatures and several models have been proposed.…”

<i>In Situ</i> EBSD Analysis on the Crystal Orientation Relationship between Ferrite and Austenite during Reverse Transformation of an Fe-Mn-C Alloy

“…The mechanism of variant selection of transforming γ has been discussed in the literature. In studies on the texture memory effect during α−γ−α transformation [14][15][16][17][18][19][20][21][22] , it is commonly suggested that the γ texture after the reverse transformation is not randomly selected but is determined under the rule on the variant selection of transforming γ. Various models to explain the variant selection rules of transforming γ during reverse transformation have been proposed.…”

Effect of Aluminum Content on the Mechanical Properties of Dual Stabilized Ti&ndash;Nb Interstitial Free High Strength Steel (IF-HSS)

“…[1][2][3][4][5][6] However, there are more severe forming applications, for example such as floor, fender or side panels, where similar types of IF-HSS steels might be applied but are not because of their slightly inferior formability. Therefore, there is an interest in increasing the formability of IF-HSS without decreasing their strength.…”