Abstract: A mechanical steel part in steel with high characteristics, characterized in that its composition, comprising in weight percentages, is 0.05%?C?0.25%; 1.2%?Mn?2%; 1%?Cr?2.5%; wherein the contents of C, Mn and Cr are such that (830-270C %-90 Mn %-70Cr %)?560; 0<Si?1.55; 0<Ni?1%; 0<Mo?0.5%; 0<Cu?1%; 0<V?0.3%; 0<Al?0.1%; 0<B?0.005%; 0<Ti?0.03%; 0<Nb?0.06%; 0<S?0.1%; 0<Ca?0.006%; 0<Te?0.03%; 0<Se?0.05%; 0<Bi?0.05%; 0<Pb?0.1%; the remainder of the steel part being iron and impurities resulting from processing, and wherein the in that its structure of the steel is bainitic and contains no more than a total of 20% of martensite and/or pro-eutectoid ferrite and/or pearlite.

Abstract: A spring steel with high fatigue resistance in air and in corrosive conditions and with high resistance to cyclic sag, having the composition in weight percent: C=0.45-0.70% Si=1.65-2.50% Mn=0.20-0.75% Cr=0.60-2% Ni=0.15-1% Mo=traces-1% V=0.003-0.8% Cu=0.10-1% Ti=0.020-0.2% Nb=traces-0.2% AI=0.002-0.050% P=traces-0.015% S=traces-0.015% O=traces-0.0020% N=0.0020-0.0110% the balance being iron, and impurities resulting from the steel making process, where the carbon equivalent Ceq content calculated according to the formula: Ceq %=[C %]+0.12 [Si %]+0.17 [Mn %]?0.1 [Ni %]+0.13 [Cr %]?0.24 [V %] is between 0.80 and 1.00%, and whose hardness, after quenching and tempering, is greater than or equal to 55 HRC.

Abstract: The invention relates to a steel for mechanical construction, wherein its composition in percentages by weight is: 0.35%?C?1.2%; 0.10%?Mn?2.0%; 0.10%?Si?3.0%; traces?Cr?4.5%; traces?Mo?2.0%; traces?Ni?4.5%; traces?V?0.5%; traces?Cu?3.5% with Cu?Ni %+0.6 Si % if Cu?0.5%; traces?P?0.200%, traces?Bi?0.200%, traces?Sn?0.150%, traces?As?0.100%, traces?Sb?0.150%, with 0.050%?P %+Bi %+Sn %+As %+Sb %?0.200%, traces?Al?0.060%; traces?Ca ?0.050%; traces?B?0.01%; traces?S?0.200%; traces?Te?0.020%; traces?Se?0.040%; traces?Pb?0.070%; traces?Nb?0.050%; traces?Ti?0.050%; the remainder being iron and impurities resulting from the manufacture.

Abstract: A carbon or low-alloy steel is provided with improved machinability. The carbon content of the steel is less than 1.5% and the sum of the alloy elements contained therein is less than 9%. The steel contains oxide and sulfide inclusions, and the chemical composition of the steel includes 0.1%≦Mn, 0.01%≦Al≦0.05%, 0.025%≦S≦0.3%, 0.002%≦Ca, O≦0.0015% by weight; the “KO oxides” cleanness index is less than 30, all the oxides are lime aluminates, and the average calcium content of type 2, type 3, type 4 and type 5 inclusions is less than 30%. A process of manufacturing such steel and an oxide-coated wire for its manufacture are also provided.

Abstract: A method of annealing of siderurgical products comprised of carbon steel having a chromium content in the range 0.15-1.5 wt. % and a manganese content also in the range 0.15-1.5 wt. %, whereby said products are held in an annealing furnace under nitrogen atmosphere to bring about globulization of the perlite; characterized in that oxygen is added to this atmosphere, in an amount greater than or equal to 0.5 vol. %.