COATED TEMPERED SHEET STEEL CHARACTERISED BY EXCELLENT DEFORMABILITY AND METHOD FOR MANUFACTURE THEREOF Russian patent published in 2021 - IPC C22C38/06 C22C38/12 C22C38/14 C22C38/38 C21D8/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy, namely to coated tempered sheet steel used for manufacturing vehicle parts. The steel has a chemical composition containing elements, wt.%: 0.17 ≤ carbon ≤ 0.25, 1.8 ≤ manganese ≤ 2.3, 0.5 ≤ silicon ≤ 2.0, 0.03 ≤ aluminium ≤ 1.2, sulfur ≤ 0.03, phosphorus ≤ 0.03, if necessary, at least one element from: chromium ≤ 0.4, molybdenum ≤ 0.3, niobium ≤ 0.04 and titanium ≤ 0.1, the rest is iron and inevitable impurities. The microstructure of the sheet steel includes, in surface area percentages, from 4 to 20% retained austenite, from 0 to 15% ferrite, from 40 to 85% tempered bainite and no less than 5% tempered martensite, wherein the total amount of tempered martensite and retained austenite is within the range from 10 to 30%.

EFFECT: production of sheet steel with the required mechanical properties is ensured.

13 cl, 5 tbl