A composition ultra high strength steel, the manufacturing process of a steel product ultrahigh strength and product obtained.

摘要

A steel product having the following characterized composition that said steel product comprises at least a bainitic phase and / or a martensitic phase, and wherein the phase distribution is such that the sum of bainitic and martensitic phase is greater than 35 %, and wherein the tensile strength is greater than 1000 MPa. - C: between 1000ppm and 2500ppm - Mn: between 12000ppm and 20000ppm - Si: between l500ppm and 3000ppm - P: between 100ppm and 600ppm - S: maximum 50ppm - N: maximum 100ppm - Al: maximum 1000ppm - B between 10ppm and 35ppm - Tifactor = Ti-3.42N + 10: between 0ppm and 400ppm - Nb: between 200ppm and 800ppm - Cr between 2500ppm and 7500ppm - Mo between 1000ppm and 2500ppm - Ca between 0 and 50ppm the remainder being iron and incidental impurities.