The invention relates to an apparatus (10) for the thermal treatment of metallic products, which comprises (a) a support and transport plane (24); (b) at least one collector module (12) comprising at least one collector (14, 16), the collector (14) being provided with a perforated plate (22) facing the support and transport plane (24); (b-2) a conduit (20) connected to said at least one collector (14), and (b-3) integrated in said conduit (20), at least one stop valve (18). The stop valve (18) is situated at a distance from the collector (14) which does not exceed 60 cm. The perforated plate (22) is provided with holes which are arranged in rows parallel to each other but not in parallel rows with respect to the sides of said perforated plate. The rows are inclined with respect to two opposite sides of the plate (22) of an acute angle.

The invention relates to an apparatus (10) for the thermal treatment of metallic products, which comprises (a) a support and transport plane (24); (b) at least one collector module (12) comprising at least one collector (14, 16), the collector (14) being provided with a perforated plate (22) facing the support and transport plane (24); (b-2) a conduit (20) connected to said at least one collector (14), and (b-3) integrated in said conduit (20), at least one stop valve (18). The stop valve (18) is situated at a distance from the collector (14) which does not exceed 60 cm. The perforated plate (22) is provided with holes which are arranged in rows parallel to each other but not in parallel rows with respect to the sides of said perforated plate. The rows are inclined with respect to two opposite sides of the plate (22) of an acute angle.

The invention relates to a turnout rail production technology, in particular to a deeply-hardened-surface turnout rail with high degree of undercooling and the preparation method thereof. The invention aims to solve the technical problem by providing a deeply-hardened-surface turnout rail with high degree of undercooling featured in even hardness distribution and a deeply hardened surface layer and the preparation method thereof. The method is described as follows: feeding molten iron for converter smelting.fwdarw.furnace rear argon blowing station.fwdarw.LF refining.fwdarw.RH vacuumization.fwdarw.casting steel blanks.fwdarw.slow cooling in the slow cooling pit.fwdarw.austenitic homogenization.fwdarw.rail rolling.fwdarw.heat treatment; in the converter smelting process, adding 0.2-0.3% Cr, 0.04-0.06 V and 0.75-0.80% C; the heat treatment process is divided into two cooling stages. The turnout rail prepared with the method described in the invention has a deeper deeply-hardened surface layer; the hardness is distributed more evenly, the anti-contact fatigue performance is higher and the resistance to wearing is ideal.

GPa-grade bainite steel having an ultra-high yield ratio, containing, in addition to Fe, the following chemical elements in mass percentages: 0.12-0.24% of C; 0.2-0.5% of Si; 1.3-2.0% of Mn; 0.001-0.004% of B; 0.01-0.05% of Al; and at least one of Cr, Nb, Ti, and Mo, wherein Cr≤0.4%, Nb≤0.06%, Ti≤0.1%, and Mo≤0.4%. Also disclosed are a manufacturing method and annealing process for the steel.

GPa-grade bainite steel having an ultra-high yield ratio, containing, in addition to Fe, the following chemical elements in mass percentages: 0.12-0.24% of C; 0.2-0.5% of Si; 1.3-2.0% of Mn; 0.001-0.004% of B; 0.01-0.05% of Al; and at least one of Cr, Nb, Ti, and Mo, wherein Cr≤0.4%, Nb≤0.06%, Ti≤0.1%, and Mo≤0.4%. Also disclosed are a manufacturing method and annealing process for the steel.

A method for preparing a Bainite hot-working die, includes: 1) weighing and mixing alloy raw materials including: C: 0.50-0.60%, Si: 0.20-0.25%, Mn: 1.00-1.50%, W: 2.10-3.00%, Mo: 3.50-5.00%, V: 0.50-1.00%, Co: 0.60-1.10%, P≤0.02%, rare earth (RE): 0.01-0.10%, (RE)/(S)>3.0, (RE)×(S)<0.004%, the balance being Fe and impurities; smelting, casting, annealing the alloy raw materials, to yield steel billets; 2) forging the steel billets to obtain Bainite die billets; 3) mechanically roughening the Bainite die billets, to yield die inserts; 4) tempering the die inserts, to yield hardened Bainite die inserts through secondary strengthening of Bainite; 5) mechanically machining the hardened Bainite die inserts to yield precisely sized die inserts; 6) nitriding the precisely sized die inserts; and 7) assembling the die inserts to yield a Bainite hot-working die.

A method for preparing a Bainite hot-working die, includes: 1) weighing and mixing alloy raw materials including: C: 0.50-0.60%, Si: 0.20-0.25%, Mn: 1.00-1.50%, W: 2.10-3.00%, Mo: 3.50-5.00%, V: 0.50-1.00%, Co: 0.60-1.10%, P≤0.02%, rare earth (RE): 0.01-0.10%, (RE)/(S)>3.0, (RE)×(S)<0.004%, the balance being Fe and impurities; smelting, casting, annealing the alloy raw materials, to yield steel billets; 2) forging the steel billets to obtain Bainite die billets; 3) mechanically roughening the Bainite die billets, to yield die inserts; 4) tempering the die inserts, to yield hardened Bainite die inserts through secondary strengthening of Bainite; 5) mechanically machining the hardened Bainite die inserts to yield precisely sized die inserts; 6) nitriding the precisely sized die inserts; and 7) assembling the die inserts to yield a Bainite hot-working die.

A steel for leaf spring including of the following elements 0.4% ≦ C ≦ 0.7 %; 0.5% ≦ Mn ≦1.5 %;1% ≦ Si ≦ 2.5 %; 0.001% ≦ Al ≦ 0.1%; 0.1% ≦ Ni ≦ 1%;0.2% ≦ Cr ≦ 1.5 %; 0 ≦ P ≦ 0.09%; 0 ≦ S ≦ 0.09%; 0% ≦ N ≦ 0.09%; 0% ≦ Mo ≦ 0.5%; 0% ≦ V ≦ 0.2%; 0% ≦ Nb ≦ 0.1%; 0% ≦ Ti ≦ 0.1%; 0% ≦ Cu ≦ 1%; 0% ≦ B ≦ 0.008%; 0% ≦ Sn ≦ 0.1%; 0% ≦ Ce ≦ 0.1%; 0% ≦ Mg ≦ 0.10%; 0% ≦ Zr ≦ 0.10%; the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel including, by area percentage, 75% to 98% of Martensite, 2% to 20% of Residual Austenite, with a cumulative optional presence of bainite and ferrite between 0% to 5%.

A steel for leaf spring including of the following elements 0.4% ≦ C ≦ 0.7 %; 0.5% ≦ Mn ≦1.5 %;1% ≦ Si ≦ 2.5 %; 0.001% ≦ Al ≦ 0.1%; 0.1% ≦ Ni ≦ 1%;0.2% ≦ Cr ≦ 1.5 %; 0 ≦ P ≦ 0.09%; 0 ≦ S ≦ 0.09%; 0% ≦ N ≦ 0.09%; 0% ≦ Mo ≦ 0.5%; 0% ≦ V ≦ 0.2%; 0% ≦ Nb ≦ 0.1%; 0% ≦ Ti ≦ 0.1%; 0% ≦ Cu ≦ 1%; 0% ≦ B ≦ 0.008%; 0% ≦ Sn ≦ 0.1%; 0% ≦ Ce ≦ 0.1%; 0% ≦ Mg ≦ 0.10%; 0% ≦ Zr ≦ 0.10%; the remainder composition being composed of iron and unavoidable impurities caused by processing, the microstructure of the steel including, by area percentage, 75% to 98% of Martensite, 2% to 20% of Residual Austenite, with a cumulative optional presence of bainite and ferrite between 0% to 5%.

The present disclosure discloses a hot-forging die with the conformal meshy structured cavity surface layer and a preparation method thereof. A large-scale hot-forging die includes a die substrate, and a sandwiched layer, a transition layer and a reinforcement layer are formed on the die substrate in sequence. The reinforcement layer and the transition layer are separated into a plurality of small units by the grooves. All the grooves are interconnected and communicated to form a meshy structure. The transition layer grooves are filled with ordinary soft material; the reinforcement layer grooves are filled with high temperature resistant soft material. The reinforcement layer material and the high temperature resistant soft material of the present disclosure cooperate with each other to obtain a cavity surface layer with properties of both hard and soft, strong and tough, which can fully release the large tensile stress that may occur on the surface of the die cavity during the welding process and under the service conditions of the die, so as to avoid hot cracks during welding process and service process.