CN114054665A

CN114054665A - BG801 steel ball forging method

Info

Publication number: CN114054665A
Application number: CN202111388130.3A
Authority: CN
Inventors: 吴玉成; 关云朋; 安敏; 付中元; 刘明; 刘永宝; 王教翔; 于遨海; 穆强; 夏云志; 王伟錡; 索志鹏; 于祎航
Original assignee: AVIC Harbin Bearing Co Ltd
Current assignee: AVIC Harbin Bearing Co Ltd
Priority date: 2021-11-22
Filing date: 2021-11-22
Publication date: 2022-02-18

Abstract

The invention discloses a BG801 steel ball forging method, and relates to a BG801 steel ball forging method. The invention aims to solve the problem that the steel ball is difficult to forge and form due to the characteristics of good strength, toughness and the like of the existing BG801 steel, and the method comprises the following steps: heating the blank, wherein the initial forging temperature is 1040-1060 ℃, and the heat preservation time is (1.5-2 x phi) min; then forging and forming, ash cooling and annealing are carried out to finish the process. According to the invention, through the adjustment of the process parameters of temperature heating and heat preservation time, the problem that the BG801 steel ball is difficult to form is solved, and further, excellent internal structure and good performance are obtained. The invention is applied to the field of forging of steel balls.

Description

BG801 steel ball forging method

Technical Field

The invention relates to a BG801 steel ball forging method.

Background

BG801 is used as improved CSS42L surface hardening bearing steel, belongs to 3 rd generation bearing material, has the service temperature of 400-500 ℃, has good comprehensive performance and corrosion resistance, and is mainly used for transmission structure parts such as aviation bearings, gears and the like. However, the BG801 material has the characteristics of narrow forging temperature, large parallel resistance, good strength and toughness in a high-temperature state and the like, is easy to overheat or over-burn, so that the steel ball is difficult to forge and form,

disclosure of Invention

The invention aims to solve the problem that the BG801 steel is difficult to forge and form due to the characteristics of good strength, toughness and the like at present, and provides a BG801 steel ball forging method.

The BG801 steel ball forging method comprises the following steps:

firstly, heating a blank, wherein the initial forging temperature is 1040-1060 ℃, and the heat preservation time is (1.5-2 x phi) min; wherein phi is the diameter of the blank and the unit is mm;

secondly, forging and forming the blank heated in the step one, wherein the finish forging temperature is more than 900 ℃, and obtaining a forged piece;

and thirdly, performing ash cooling on the forged piece obtained in the second step, and then annealing to obtain the finished product.

According to the invention, the problem of difficulty in forming the BG801 steel ball is solved by adjusting the technological parameters of temperature heating and heat preservation time, so that excellent internal structure and good performance are obtained, the requirement of grade 4 or thinner is met by detecting the steel ball crystal grains after forging, and the hardness HB321 after forging annealing meets the requirement of being less than or equal to HB 390.

Drawings

FIG. 1 is a BG801 Steel ball grain size photograph;

FIG. 2 is a 4-grade standard grain size comparison photograph;

FIG. 3 is a BG801 steel ball forging process curve.

Detailed Description

The first embodiment is as follows: the BG801 steel ball forging method of the embodiment comprises the following steps:

The BG801 steel ball forging process curve is shown in figure 3.

The second embodiment is as follows: the first difference between the present embodiment and the specific embodiment is: the annealing process in the third step comprises the following steps: firstly preserving heat at 750-760 ℃ for 3h, then preserving heat at 830-840 ℃ for 6-7 h, preserving heat at 700-720 ℃ for 11-12 h, then cooling to 680 ℃, then furnace cooling to 500-550 ℃, and finally discharging from the furnace for air cooling. The rest is the same as the first embodiment.

The third concrete implementation mode: the present embodiment differs from the first or second embodiment in that: during annealing, the forged piece is placed in an annealing box and sealed by a cover, and the sealing material is a mixture of cast iron chips and charcoal powder. The others are the same as in the first or second embodiment.

The fourth concrete implementation mode: the difference between this embodiment mode and one of the first to third embodiment modes is: the charcoal powder accounts for 1-2% of the total mass of the mixture of the cast iron scraps and the charcoal powder. The rest is the same as one of the first to third embodiments.

The fifth concrete implementation mode: the difference between this embodiment and one of the first to fourth embodiments is: cooling to 680 ℃ at a rate of 20 ℃/h. The rest is the same as one of the first to fourth embodiments.

The effect of the invention is verified by the following examples:

example 1: the method for forging the BG801 steel ball in the embodiment comprises the following steps:

firstly, heating a blank, wherein the initial forging temperature is 1040 ℃, and the heat preservation time is (1.5 x phi) min; wherein phi is the diameter of the blank and the unit is mm;

and III, performing ash cooling on the forged piece obtained in the step II, and then annealing, wherein the annealing process is as follows: firstly preserving heat at 750-760 ℃ for 3h, then preserving heat at 830-840 ℃ for 6-7 h, preserving heat at 700-720 ℃ for 11-12 h, then cooling to 680 ℃, then furnace cooling to 500-550 ℃, and finally discharging from the furnace for air cooling.

The grain size test method of the BG801 steel ball is carried out according to the GB/T6394 method, and the qualified grade is not less than 4 grade (a 4-grade standard grain size photograph is shown in figure 2). And (5) keeping the temperature of a test sample quenching system at 1065 +/-5 for 1h, and cooling with oil.

The grain size photograph of the forged BG801 steel ball is shown in FIG. 1, and the average grain size of the core part is 6.5

According to the embodiment, the problem that the BG801 steel ball is difficult to form is solved by adjusting the technological parameters of temperature heating and heat preservation time, so that excellent internal structure and good performance are obtained, and the requirement of grade 4 or finer is met by detecting the crystal grains of the forged steel ball.

Claims

The method for forging the BG801 steel ball is characterized by comprising the following steps of:

firstly, heating a blank, wherein the initial forging temperature is 1040-1060 ℃, and the heat preservation time is (1.5-2 x phi) min; wherein phi is the diameter of the blank and the unit is mm;

secondly, forging and forming the blank heated in the step one, wherein the finish forging temperature is more than 900 ℃, and obtaining a forged piece;

and thirdly, performing ash cooling on the forged piece obtained in the second step, and then annealing to obtain the finished product.
2. The forging method of BG801 steel balls as claimed in claim 1, wherein the annealing process in step three is: firstly preserving heat at 750-760 ℃ for 3h, then preserving heat at 830-840 ℃ for 6-7 h, preserving heat at 700-720 ℃ for 11-12 h, then cooling to 680 ℃, then furnace cooling to 500-550 ℃, and finally discharging from the furnace for air cooling.
3. The BG801 steel ball forging method as in claim 1, wherein the forging is placed in an annealing box and sealed by a cover during annealing, and the sealing material is a mixture of cast iron chips and charcoal powder.
4. The method for forging BG801 steel balls as claimed in claim 2, wherein the charcoal powder accounts for 1-2% of the total mass of the mixture of the cast iron filings and the charcoal powder.
5. The forging method of BG801 steel balls as claimed in claim 2, wherein the cooling is performed at a rate of 20 ℃/h to 680 ℃.