PREFORMED IN HOT STATE WELDED STEEL PART WITH HIGH MECHANICAL STRENGTH AND METHOD OF ITS MANUFACTURING Russian patent published in 2015 - IPC B32B15/01 B23K31/02 B23K35/30 B23K33/00 C22C38/04 C22C38/18 C22C38/14 C21D1/673 

FIELD: metallurgy.

SUBSTANCE: part blank is made by butt welding of at least one first and one second plates. Plate contains at least partially steel substrate and preliminary coating, containing layer of intermetallic alloy in contact with steel substrate coated with layer of aluminium alloy or alloy based on aluminium. Layer (19, 20) of metal alloy is removed from edges (36) in the direct vicinity to zone (35) of metal welding. Layer (17, 18) of intermetallic alloy is kept on place. Above of at least part of zone (35) of metal welding the ratio between carbon content in zone of metal welding and carbon content in substrate (25, 26) of the first (11) or second (12) plate which has maximum carbon content Cmax, is from 1.27 to 1.59. Welding blank (37) is heated such that to obtain the metal of welding zone (35) with completely austenite structure, the said welding blank is hot formed and heated to receive the steel part, the produced steel part is cooled with regulated rate.

EFFECT: assurance of set characteristics of mechanical strength.

29 cl, 9 dwg, 2 tbl