Submarine hull steel having enhanced weldability

Assembled submarine hull steel components, each steel component having a chemical composition consisting of, in weight percent:

• 0.030%≦C<0.080%
• 0.040%≦Si≦0.13%
• 0.1%≦Mn≦1.4%
• 2%≦Ni≦4%
• Cr≦0.3%
• 0.30%≦Mo+W/2+3(V+Nb/2+Ta/4)≦0.89%
• 0.15%≦Mo≧0.89%
• 0.11%≦W≦1.48%
• V+Nb/2+Ta/4≦0.004%
• Nb≦0.004%
• Cu≦0.45%
• Al≦0.1%
• Ti≦0.04%
• N≦0.0300%
• impurities resulting from the production operation, said impurities including
• B≦0.0005%,
• P+S≦0.015%,
• the balance being iron, the chemical composition complying with the condition:
• 410≦540×C0.25+245[Mo+W/2+3(V+Nb/2+Ta/4)]0.30≦460,
• the steel components having a structure comprising:
• at least 90% of martensite,
• a maximum of 5% of residual austenite, and
• a maximum of 5% of ferrite,
• the steel components having an elastic limit of between 480 MPa and 620 MPa, wherein the steel components have a thickness of between 15 mm and 150 mm, of forged or rolled steel which has been quenched and tempered,
• wherein the components are assembled by welding by means of:
• arc welding using a coated electrode welding process, or
• arc welding using a solid wire MIG welding process,
• said welding being started with no preheating or with preheating to a temperature less than or equal to 25° C., including when the welding is carried out on a site on which the temperature is less than 0° C., and the welding of steel components comprises using filler metal.