STEEL PLATE OF HOT-STAMPED PRODUCT AND METHOD OF ITS MANUFACTURING Russian patent published in 2015 - IPC C22C38/06 C21D9/46 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to manufacturing of the steel plate used to manufacture hot-stamped products. Plate is made of steel containing in wt %: C: from 0.15 to 0.35, Si: from 0.01 to 1.0, Mn: from 0.3 to 2.3, Al: from 0.01 to 0.5, Fe and inevitable admixture - rest, at that it contains P as admixture: 0.03 or less; S: 0.02 or less and N: 0.1 or less. The plate is manufactured by hot rolling, cold rolling and recrystallisation annealing. The annealing is performed by two stages: at the first stage the plate is heated from room temperature to 600-700°C with average rate from 8 to 25°C/s, at the second stage the plate is heated to temperature from 720 to 820 with average rate from 2.5 to 7°C/s. Standard deviation of Vickers hardness determined in position 20 micron from steel plate surface in direction of plate thickness in plate cross-section is 20 or below.

EFFECT: products manufactured from plates have high fatigue characteristics.

9 cl, 6 dwg, 9 tbl, 5 ex