Steel sheet for manufacturing press hardened parts, press hardened part having a combination of high strength and crash ductility, and manufacturing methods thereof

A steel sheet for manufacturing a press hardened steel part, the steel sheet being made of a steel having a composition comprising, by weight

• 0.15%≤C≤0.22%
• 3.5%≤Mn<4.2%
• 0.001%≤Si≤1.5%
• 0.3%≤Al≤0.9%
• 0.001%≤Cr≤1%
• 0.001%≤Mo≤0.3%
• 0.001%≤Ti≤0.040%
• 0.0003%≤B≤0.004%
• 0.001%≤Nb≤0.060%
• 0.001%≤N≤0.009%
• 0.0005%≤S≤0.003%
• 0.001%≤P≤0.020%
• a remainder being iron and unavoidable impurities;
• said steel sheet having a microstructure consisting of, in surface fraction:
• less than 50% of ferrite;
• between 1% and 20% of retained austenite;
• cementite, such that a surface density of cementite particles having a larger dimension higher than 60 nm is lower than 107/mm2;
• and
• a complement consisting of bainite and/or martensite;
• the retained austenite having an average Mn content, by weight percent, of at least 1.1*Mn %, wherein Mn % designates the Mn content, by weight percent, in the composition.