CN103805891A - Preparation method of steel billet for high-speed train bearing - Google Patents

Abstract

The invention discloses a preparation method of a steel billet for a high speed train bearing, the steel billet for the high speed train bearing comprises the following chemical components by weight: 0.26-0.30 % of C, 0.4-0.6 % of Si, 0.2-0.4 % of Mn, 1.8-2.0 % of Cr, 5.5-5.7% of Ni, 1.6-1.8 % of Mo, 0.04-0.06% of Ti, 0.1-0.2 % of V, 0.001-0.003% of B, less than or equal to 0.008 % of P, less than or equal to 0.010% of S, and the balance of Fe and inevitable impurities; the preparation method comprises the following steps: 1) smelting and blank casting, to be more specific, using vacuum induction and vacuum consumable process combined with a super pure smelting process to enable the composition of steel to meet the limit; and 2) forging, to be more specific, forging bearing blanks at the open forging temperature of 1130-1150 DEG C and the final forging temperature of 910-930 DEG C.

Description

The preparation method of steel billet for a kind of High-speed Train Bearing

Technical field

The present invention relates to technical field of ferrous metallurgy, relate in particular to the preparation method of a kind of High-speed Train Bearing steel billet.

Background technology

Bearing is as the key member of bullet train, special car, metallurgy and engineering machinery transmission, and it is not only the restraining factors of overall performance, life and reliability, affects stability, the security of complete machine simultaneously.Along with transferring energy increases, rotating speed, temperature and life-span increase, and the shock action that wheel set bearing that particularly the violent hunting of bullet train causes is strong and the high impact loads of rolling mill bearing, require bearing to have more high bearing capacity, be bearing steel core high-strong toughness, surface duplex hardening; Bearing is at a high speed, can work reliably by continous-stable under HI high impact state, and for example maintenance mileage in high ferro wheel set bearing unit requires to reach 1,200,000 kilometers, and therefore high high reliability, long lifetime, the high stability under tough of bearing steel seems most important.

State's neck bearing thermal treatment process levels is very fast at present, uses for reference American-European advanced bearing materials and technique, and domestic high-performance external diameter exceedes the exploitation of 200mm large size bearing and obtained marked improvement.High ferro bearing is by carburizing bearing steel making, and bearing steel core has excellent toughness, and carburized surface hardness is high, can bear intense impact load, and anti-fatigue performance is good.Although the U.S., Europe are different in the standard of following aspect high-performance carburizing bearing material with Japan, select also difference to some extent of bearing materials.The reliable and secure property of metallurgical quality and the contour performance bearing of delicate tissues remarkably influenced bullet train is known together by people.Bearing in China's automobile, railway, armored vehicle and marine engine and transmission system, because of service condition difference, bearing steel adopts respectively the converted steel such as 20CrNiMo, 18Cr2Ni4WA and 12CrNi3A.In addition, bearing applying working condition difference both at home and abroad, as China Express Railway wheel set bearing is compared, abroad its Service Environment is more harsh and complicated, shows as working time longer, and temperature variation is larger, the influence such as rail quality and planeness thereof etc.To particularly higher and more comprehensive performance and the specification of quality of wheel set bearing steel proposition of bearing steel for bullet train.

Summary of the invention

The preparation method who the object of the invention is to propose a kind of High-speed Train Bearing steel billet, this bearing steel base has excellent fatigue property, and has good obdurability and good shock resistance.

For reaching this object, the present invention by the following technical solutions:

A preparation method for steel billet for High-speed Train Bearing, the chemical composition of described bearing steel base is made up of following component by weight percentage: C:0.26-0.30, Si:0.4-0.6, Mn:0.2-0.4, Cr:1.8-2.0, Ni:5.5-5.7, Mo:1.6-1.8, Ti:0.04-0.06, V:0.1-0.2, B:0.001-0.003, P≤0.008, S≤0.010, remaining is Fe and inevitable impurity; Described preparation method comprises the steps:

1) smelt strand: adopt vacuum induction and the vacuum consumable technique super clean smelting technology that combines, make the composition of steel meet above-mentioned restriction;

2) forge: open and forge temperature at 1130-1150 ℃, final forging temperature 910-930 ℃; Be forged into bearing base.

The present invention has following beneficial effect:

The present invention by the adjustment to chemical composition, by the control to Cr, Ni, Mo content, to adjust the obdurability of steel, and allocates the content of Ti, V and B, makes to generate in steel appropriate carbide and is evenly distributed, size to fit.Thereby make invention crystalline grain of steel tiny, organize meticulous, intensity, toughness and fatigue property to obtain and increase substantially, its mechanical property is: tensile strength Rm>=1500MPa, ballistic work A _kU>=145J, contact fatigue life cycle index under 4000MPa stress reaches 10 ⁹; Cycle index 10 ⁷lower bending fatigue limit intensity is not less than 970MPa.Thereby be suitable for the use of High-speed Train Bearing.

Embodiment

Embodiment mono-

A preparation method for steel billet for High-speed Train Bearing, the chemical composition of described bearing steel base is made up of following component by weight percentage: C:0.26, Si:0.6, Mn:0.2, Cr:2.0, Ni:5.5, Mo:1.8, Ti:0.04, V:0.2, B:0.001, P≤0.008, S≤0.010, remaining is Fe and inevitable impurity; Described preparation method comprises the steps:

1) smelt strand: adopt vacuum induction and the vacuum consumable technique super clean smelting technology that combines, make the composition of steel meet above-mentioned restriction;

2) forge: open and forge temperature at 1130 ℃, 930 ℃ of final forging temperatures; Be forged into bearing base.

Embodiment bis-

A preparation method for steel billet for High-speed Train Bearing, the chemical composition of described bearing steel base is made up of following component by weight percentage: C:0.30, Si:0.4, Mn:0.4, Cr:1.8, Ni:5.7, Mo:1.6, Ti:0.06, V:0.1, B:0.003, P≤0.008, S≤0.010, remaining is Fe and inevitable impurity; Described preparation method comprises the steps:

1) smelt strand: adopt vacuum induction and the vacuum consumable technique super clean smelting technology that combines, make the composition of steel meet above-mentioned restriction;

2) forge: open and forge temperature at 1150 ℃, 910 ℃ of final forging temperatures; Be forged into bearing base.

Embodiment tri-

A preparation method for steel billet for High-speed Train Bearing, the chemical composition of described bearing steel base is made up of following component by weight percentage: C:0.28, Si:0.5, Mn:0.3, Cr:1.9, Ni:5.6, Mo:1.7, Ti:0.05, V:0.15, B:0.002, P≤0.008, S≤0.010, remaining is Fe and inevitable impurity; Described preparation method comprises the steps:

1) smelt strand: adopt vacuum induction and the vacuum consumable technique super clean smelting technology that combines, make the composition of steel meet above-mentioned restriction;

2) forge: open and forge temperature at 1140 ℃, 920 ℃ of final forging temperatures; Be forged into bearing base.

Claims (1)

1. a preparation method for steel billet for High-speed Train Bearing, is characterized in that, the chemical composition of described bearing steel base is made up of following component by weight percentage: C:0.26-0.30, Si:0.4-0.6, Mn:0.2-0.4, Cr:1.8-2.0, Ni:5.5-5.7, Mo:1.6-1.8, Ti:0.04-0.06, V:0.1-0.2, B:0.001-0.003, P≤0.008, S≤0.010, remaining is Fe and inevitable impurity; Described preparation method comprises the steps:

1) smelt strand: adopt vacuum induction and the vacuum consumable technique super clean smelting technology that combines, make the composition of steel meet above-mentioned restriction;

2) forge: open and forge temperature at 1130-1150 ℃, final forging temperature 910-930 ℃; Be forged into bearing base.