Steel part having high strength and high bendability

A process for producing a steel part comprising the following steps:

• casting a semi-product at a casting speed equal to or greater than 3.0 m/min, the semi-product having a composition
• comprising, by weight %:
• 0.18≤C≤0.27
• 0.18≤Si≤0.30
• 1.0≤Mn≤1.5
• 0.14≤Cr≤0.25
• 0.02≤Al≤0.06
• 0.02≤Ti≤0.06
• 0.0015≤B≤0.0040
• 0≤S≤0.008
• 0≤P≤0.04
• 0≤N≤0.020
• 0≤Mo≤0.3
• 0≤Nb≤0.1
• 0≤V≤0.3
• 0≤Cu≤0.25
• 0≤Ni≤0.25
• 0≤Sn≤0.05
• 0≤As≤0.03
• 0≤Sb≤0.03
• 0≤Pb≤0.03
• a remainder of the composition being iron and unavoidable impurities resulting from processing;
• optionally cooling the semi-product after casting,
• maintaining or reheating the semi-product in a temperature range of 1075° C. to 1200° C.;
• hot-rolling the semi-product using a finishing temperature equal to or above 850° C. and a coiling temperature equal to or above 525° C. to obtain a hot rolled steel sheet;
• pickling the hot rolled steel sheet;
• optionally cold-rolling the hot rolled steel sheet to obtain a cold rolled steel sheet;
• applying an annealing step to the hot rolled or cold rolled steel sheet by heating in an annealing furnace, to an annealing temperature TA, expressed in ° C., comprised from 700° C. to 850° C., the furnace further comprising a soaking section where the steel sheet is maintained at the temperature TA for a holding time tA, comprised from 10 seconds to 20 minutes;
• optionally cooling the annealed steel sheet to a temperature range from 400° C. to 700° C.;
• optionally coating the annealed steel sheet with a metallic coating;
• cutting the steel sheet to a predetermined shape, so as to obtain a steel blank;
• heating the steel blank to a temperature equal to or above Ac3 and equal to or lower than 950° C. during 10 seconds to 15 minutes to obtain a heated steel blank;
• transferring the heated steel blank to a forming press;
• hot-forming the heated blank in the forming press to obtain a formed part;
• die-quenching the formed part to obtain a steel part;
• and
• optionally paint baking said steel part at a temperature from 150° C. to 250° C. for a time comprised from 10 minutes to 2 hours.