KR102511362B1 - Method for hardening pulling-straightening roller through thermal treatment - Google Patents

Abstract

The present invention relates to a method for heat treatment of a tension roller, particularly a method for heat treatment of a full hardening tension roller, and includes the following procedures: by performing total quenching and total tempering on the tension roller, After complete hardening, tempering is performed on the ends of the non-working section at both ends of the work roll of the tension roller so that the hardness of the non-working section at both ends of the work roll is smaller than the hardness of the working section of the work roll, The toughness of the non-working section is made greater than the toughness of the working section. The heat treatment method of the full hardening tension roller provided by the present invention hardens the entire tension roller and makes the hardness of the working surface reach HRC61 ~ 63, which effectively improves the surface quality of the plate as well as high hardness, wear resistance, and extension of service life. can be improved By reaching more than twice the service life of the normal tension roller, the production cost can be lowered.

Description

Heat treatment method of pull hardening tension roller {METHOD FOR HARDENING PULLING-STRAIGHTENING ROLLER THROUGH THERMAL TREATMENT}

The present invention relates to a heat treatment method for a type of tension roller, and particularly to a heat treatment method for a full hardening tension roller.

The tension level is a very important equipment in the pickling line of the cold rolling mill, and its main role is to stretch, bend, and straighten the sheet strip plate shape, so that the sheet strip reaches the straightening effect, greatly improving the straightness of the sheet strip. Thus, a good quality plate can be obtained. The tension level is mainly corrected based on the tension roller, but the life of the tension roller is short, it must be replaced frequently, and it affects production and increases production cost.

This tension roller guarantees its service life mainly by increasing the surface hardness through heat treatment, and there are two methods:

One is AISI-D2 or Cr12MoV1, the process process includes: blank → roughing → tempering to HRC30-34 → precision machining pre-held size → surface quenching to hardness HRC63-65 → precision machining and polishing → finished product and shipment. Although the surface hardness reaches HRC63-65, the wear resistance is low, it is not durable, and the service life is short, and it usually needs to be replaced every 3-6 months.

The other one is used for 60CrMo, the process is: blank→priming→tempering treatment HB240-280(HRC22-28)→surface quenching to hardness HS85-95(HRC62-67)→quenching layer depth 2-3mm→surface hard Chrome plating single side 0.08 ~ 0.10mm (hard chrome plating layer). Although the wear resistance is increased, after a certain period of use, the hard chromium plating layer is worn out and a new hard chromium plating is required, so the cost is high, and the hard chromium plating layer is easily peeled off, affecting the surface quality of the sheet straightening.

In order to solve the above problems, the present invention provides a heat treatment method for a full hardening tension roller that can effectively improve the surface quality of a sheet material as well as harden the entire inside of a kind of tension roller, increase hardness, wear resistance, and extend service life. Therefore, the specific technical plan is as follows:

The heat treatment method of the full hardening tension roller is: After performing full hardening on the tension roller by performing full quenching and full tempering on the tension roller, tempering at the end of the non-working section at both ends of the work roll of the tension roller to make the hardness of the non-working section of both ends of the work roll smaller than the hardness of the working section of the work roll, and the toughness of the non-working section to be greater than the toughness of the working section.

Preferably, the entire quenching includes preheating, high temperature heating, quenching and low tempering, the temperature during the high temperature heating is 1015 to 1030 ° C, the keeping time is 20 to 25 min, and the air during the quenching is 70 to 100 ° C and the low tempering is performed twice.

Preferably, the preheating proceeds sequentially, and includes first constant temperature preheating, second constant temperature preheating, and third constant temperature preheating in which the temperature is sequentially increased: the first constant temperature preheating temperature is 350 to 450° C., and the keeping time is 2 to 3 hours. am. The secondary constant temperature preheating temperature is 550 ~ 650 ℃, the warming time is 1 ~ 2h. The third constant temperature preheating temperature is 750 ~ 850 ℃, the warming time is 0.5 ~ 1h.

Wherein, the temperature difference between the first constant temperature preheating and the second constant temperature preheating and between the second constant temperature preheating and the third constant temperature preheating is between 180 and 220°C on average.

Preferably, the low tempering temperature is 150 ~ 200 ℃, the keeping time is 2 ~ 4h.

Preferably, the full tempering includes tempering preheating and high temperature tempering. The temperature at the time of the tempering preheating is 340 ~ 380 ℃, the warming time is 2 ~ 3h. The temperature during the high-temperature tempering is 500 to 515 ° C, and the warming time is 2 to 3 h.

Preferably, the air after the low tempering is cooled to room temperature.

Preferably, the end tempering includes tempering preheating and high temperature tempering. The temperature at the time of the tempering preheating is 340 ~ 380 ℃, the warming time is 2 ~ 3h. The temperature at the time of the high-temperature tempering is 580 to 590 ° C, and the warming time is 2 to 3 h.

Compared with the previous technology, the present invention has the following advantageous effects:

The heat treatment method of the full hardening tension roller provided by the present invention hardens the entire tension roller and makes the hardness of the working surface reach HRC61 to 63, which effectively improves the surface quality of the plate as well as high hardness, wear resistance, and extension of service life. can be improved By reaching more than twice the service life of the normal tension roller, the production cost can be lowered.

1 is a diagram of the entire quenching procedure for a full hardening tension roller.
Figure 2 is an overall tempering procedure diagram for a full hardening tension roller.
3 is an end tempering procedure diagram for a full hardening tension roller.
4 is a hardness distribution diagram of a full hardening tension roller.
5 is an inspection view of a full hardening tension roller having a diameter of 16;
Figure 6 is a phase plan view of the transverse surface of the full hardening tension roller.
Fig. 7 is a phase plan view of the surface of the 1/2R position of the full hardening tension roller in the transverse direction.
Fig. 8 is a top view of the center position surface of the full hardening tension roller in the transverse direction.
9 is a phase plan view of the longitudinal surface of the full hardening tension roller.
Fig. 10 is a phase plan view of the 1/2R position surface of the full hardening tension roller in the longitudinal direction.
Fig. 11 is a top plan view of the longitudinal center position surface of the full hardening tension roller.
12 is a local detection diagram of a full hardening tension roller.

In connection with the accompanying drawings, the present invention will be further described.

As shown in FIGS. 1 to 12, the heat treatment method of the full hardening tension roller firstly performs total quenching and total tempering on the tension roller to harden the entire tension roller, and then The non-working section is end tempered, so that the hardness of the non-working section at both ends of the work roll is smaller than the hardness of the working section of the work roll, and then the toughness of the non-working section is greater than the toughness of the working section.

The full hardening mentioned in the present invention matches the hardness of the surface of the tension roller and the core, and realizes hardening as a whole. For example, when a diameter 5 is used for a tension roller with a diameter of 16, Even if used, the hardness does not change, HRC61～63 is maintained, and the roll can be repeatedly modified and used. Since it can be used in the la, the cost of the tension roller can be greatly reduced.

The tension roller includes a work roll and a connecting shaft installed at both ends of the work roll and having a smaller diameter than the work roll. The work roll includes a working section and a non-working section, and the non-working section is located at both ends of the work roll. The working section of the work roll is used for sheet straightening.

Full quenching is:

It includes preheating, high temperature heating, quenching and low tempering. The temperature during high-temperature heating is 1015~1030℃, the warming time is 20~25min, the air is cooled to 70~100℃ during quenching, and low tempering is performed twice.

Among them, low tempering is carried out twice.

In at least one embodiment, the preheating proceeds sequentially, and includes first constant temperature preheating, second constant temperature preheating, and third constant temperature preheating in which the temperature is sequentially increased: the first constant temperature preheating temperature is 350 to 450° C., and the keeping time is 2 ~3h. The secondary constant temperature preheating temperature is 550~650℃, and the warming time is 1~2h. The third constant temperature preheating temperature is 750 ~ 850 ℃, and the warming time is 0.5 ~ 1h.

In at least one embodiment, the temperature difference between the first constant temperature preheating and the second constant temperature preheating and between the second constant temperature preheating and the third constant temperature preheating averages between 180 and 220°C.

In at least one embodiment, the low tempering temperature is 150-200 ° C, and the keeping time is 2-4 h.

In one or more embodiments, total tempering includes: tempering preheating and high temperature tempering. The temperature at the time of tempering preheating is 340 ~ 380 ℃, the time is 2 ~ 3h. The temperature during high temperature tempering is 500~515℃, and the time is 2~3h.

In at least one embodiment, the air after row tempering is cooled to room temperature.

In one or more embodiments, end tempering includes: temper preheating and high temperature tempering. The temperature at the time of tempering preheating is 340 ~ 380 ℃, the time is 2 ~ 3h. The temperature during high temperature tempering is 580~590℃, and the time is 2~3h.

The heat treatment method of the full hardening tension roller is used for heat treatment of the tension roller made of tool steel, and the tool steel includes AISI-D2, Cr12MoV1, D2ESR, and the like.

As a full hardening tension roller, the tension roller is installed on both ends of the work roll and the work roll and includes a connecting shaft with a smaller diameter than the work roll, and a working section and a non-working section are installed on the work roll, and the non-working section is It is located at both ends and is connected to the connecting shaft. The hardness of the working section of the work roll and the connecting shaft is HRC61~63, and the hardness of the non-working section is HRC50~55.

Processing method of full hardening tension roller:

Blank roughing→full quenching and full tempering, hardness over HRC61~63→tempering non-working section at both ends of work rolls to HRC50~55→priming→precision processing→polishing→packing→shipping.

As shown in FIG. 4, in the cross section of both ends of the work roll, the position 20 to 50 mm inward is the non-working section, and the non-working section at both ends of the work roll is tempered to HRC50-55.

The depth of the hardened layer reaches 100%. Preliminary processing uses a lathe, precision processing uses a grinder, and the processing difficulty of the full hardening tension roller is only higher than that of the tension roller performing surface hardening.

1 to 3, the heat treatment method of the full hardening tension roller includes the following procedures:

S1. Preheating, 1st constant temperature preheating temperature is 350 ~ 450 ℃, keep warm time is 2 ~ 3h.

S2. Preheating, secondary constant temperature Preheating temperature is 550 ~ 650 ℃, keep warm time is 1 ~ 2h.

S3. Preheating, 3rd constant temperature Preheating temperature is 750 ~ 850 ℃, keep warm time is 0.5 ~ 1h.

S4. The temperature during high-temperature heating and high-temperature heating is 1015 to 1030 ° C, and the warming time is 20 to 25 min.

S5. Quenching, air cooling to 70 ~ 100 ℃.

S6. Low tempering, low tempering temperature is 150~200℃, keeping time is 2~4h, and low tempering is done twice.

S7. Cooling, cooling the air to room temperature.

S8. The temperature during full tempering and tempering preheating is 340~380℃, and the keeping time is 2~3h.

S9. During full tempering and high temperature tempering, the temperature is 500~515℃, and the keeping time is 2~3h.

S10. Cooling, cooling the entire air to room temperature.

S11. The temperature during end tempering and tempering preheating is 340~380℃, and the keeping time is 2~3h.

S12. The temperature during end tempering and high-temperature tempering is 580 ~ 590 ℃, and the keeping time is 2 ~ 3h.

S13. Cooling, cooling the air to room temperature.

Example

This embodiment includes 11 embodiments, and the tension roller is ∮16×981. The differences in each embodiment are constant temperature preheating temperature and keep warm time, high temperature heating temperature and keep warm time, quenching temperature and keep warm time, low tempering temperature and keep warm time, total tempering temperature and keep warm time, and end tempering temperature and keep warm time.

In Figures 5 and 6, 1, 2 and 3 distribution display survey points are shown. As can be seen from FIGS. 5 and 6, the surface hardness distribution of the tension roller treated by the heat treatment method of the full hardening tension roller is uniform, the surface of the sheet material that has been calibrated is smooth, there is no color difference, and color uniformity can be ensured. can

turn S11th constant temperature preheating S21st constant temperature preheating S31st constant temperature preheating S4 high temperature heating S5 quenching S6 low tempering S8 full tempering preheat S9 full high temperature tempering S11 tempering preheating S12 high temperature tempering Example 1 350℃
2.8h 550℃
2h 750℃
0.5h 1015℃
25min 70℃ 150℃
4h 350℃
3h 500℃
3h 350℃
3h 580℃
3h Example 2 360℃
2h 560℃
1.2h 760℃
0.6h 1016℃
24min 75℃ 165℃
3.8h 345℃
2.8h 505℃
2.5h 360℃
2.8h 582℃
3h Example 3 370℃
3h 570℃
1.5h 770℃
0.7h 1017℃
23min 80℃ 180℃
3.6h 350℃
2.7h 510℃
2h 370℃
2.7h 584℃
2.8h Example 4 380℃
2.2h 580℃
1.9h 780℃
0.8h 1019℃
25min 85℃ 200℃
2h 355℃
2.6h 515℃
3h 380℃
2.6h 586℃
2.5h Example 5 390℃
2.5h 590℃
1.5h 790℃
0.6h 1020℃
20min 90℃ 170℃
2.5h 360℃
2.5h 506℃
2h 390℃
2.5h 588℃
2h Example 6 400℃
2h 600℃
2h 800℃
1h 1021℃
20min 95℃ 175℃
3.5h 365℃
2.2h 508℃
2.2h 340℃
2.2h 580℃
2.6h Example 7 410℃
2.6h 610℃
1.6h 810℃
0.8h 1022℃
23min 100℃ 190℃
3h 370℃
2h 512℃
2h 345℃
2h 590℃
2.5h Example 8 420℃
3h 620℃
1h 820℃
0.5h 1025℃
22min 78℃ 160℃
3.5h 375℃
2.3h 514℃
2.3h 355℃
2.3h 584℃
2.4h Example 9 430℃
2.3h 630℃
1.8h 830℃
1h 1028℃
22min 86℃ 185℃
2.5h 380℃
2.1h 503℃
3h 375℃
2.1h 586℃
2h Example 10 440℃
2.9h 640℃
1h 840℃
0.5h 1029℃
23min 98℃ 155℃
3.5h 360℃
2h 506℃
2.6h 365℃
2h 588℃
2.3h Example 11 450℃
2h 650℃
2h 850℃
0.6h 1030℃
21min 93℃ 195℃
2.5h 355℃
2.1h 509℃
3h 360℃
2.1h 590℃
2.1h

The full hardening tension roller is applied to the narrow and wide panel tension leveler equipment, the diameter is Ψ16mm～Ψ40mm, the length is L 1450mm～L1700mm, the heat treatment hardness is HRC61～63, and the depth of the hardened layer of the tension roller is 100%. can achieve full roller curing, high wear resistance, long service life, and can effectively improve panel surface quality. In addition, the use effect is very good, and it can be used in the stainless steel, copper plate and silicon steel industry.

In the above, the technical principle according to the present invention has been described in connection with specific embodiments. Such a description is merely to aid understanding of the principles of the present invention, and is not intended to limit the protection scope of the present invention in any way. Based on this interpretation, a person skilled in the art may come up with other specific embodiments of the present invention without creative labor, and it will be understood that such a manner should fall within the protection scope of the claims of the present invention.

Claims (8)

As a heat treatment method for full hardening tension roller
After performing full quenching and full tempering on the tension roller and performing full hardening on the tension roller, tempering is performed on the ends of the non-working section at both ends of the work roll of the tension roller to A heat treatment method for a full hardening tension roller comprising a step of making the hardness of the non-working section smaller than the hardness of the working section of the work roll and making the toughness of the non-working section larger than the toughness of the working section. According to claim 1,
The total quench is:
Including preheating, high temperature heating, quenching and low tempering procedures, the temperature during the high temperature heating is 1015 to 1030 ° C, the holding time is 20 to 25 min, and the quenching is air-cooled to 70 to 100 ° C, and the low tempering is Heat treatment method of full hardening tension roller performed twice. According to claim 2,
The preheating proceeds sequentially and includes first constant temperature preheating, second constant temperature preheating, and third constant temperature preheating in which the temperature is sequentially increased,
The first constant temperature preheating temperature is 350 ~ 450 ℃, the warming time is 2 ~ 3h,
The secondary constant temperature preheating temperature is 550 ~ 650 ℃, the warming time is 1 ~ 2h,
The third constant temperature preheating temperature is 750 ~ 850 ℃, the warming time is 0.5 ~ 1h,
Heat treatment method of full hardening tension roller. According to claim 3,
The temperature difference between the first constant temperature preheating and the second constant temperature preheating and the second constant temperature preheating and the third constant temperature preheating is between 180 and 220 ° C on average,
Heat treatment method of full hardening tension roller. According to claim 2 or 3,
The low tempering temperature is 150 ~ 200 ℃, the warming time is 2 ~ 4h,
Heat treatment method of full hardening tension roller. According to claim 2 or 3,
The full tempering includes tempering preheating and high temperature tempering procedures,
The temperature during the tempering preheating is 340 ~ 380 ℃, the warming time is 2 ~ 3h,
The temperature during the high-temperature tempering is 500 ~ 515 ℃, the warming time is 2 ~ 3h,
Heat treatment method of full hardening tension roller. According to claim 2,
Heat treatment method of a full hardening tension roller that is air-cooled to room temperature after the low tempering. According to claim 1,
The end tempering includes tempering preheating and high temperature tempering,
The temperature during the tempering preheating is 340 ~ 380 ℃, the warming time is 2 ~ 3h,
The temperature during the high-temperature tempering is 580 ~ 590 ℃, the warming time is 2 ~ 3h,
Heat treatment method of full hardening tension roller.

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