Regeneration method of scrapped Cr5 forged-steel working roller

A technology for work rolls and forged steel, which is applied in heat treatment process and X stress test, regeneration of cold-rolled work rolls, selection of scrap rolls, and regeneration methods. It can solve the problems of regeneration manufacturing that have not been reported, and save purchase funds. Effect

Active Publication Date: 2014-08-20
BAOSHAN IRON & STEEL CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] So far, only the simple transformation of Cr2 rolls applied to small rolling mills (such as Chinese patent 93111115.3, involving a process for the transformation of waste rolls), has not been reported for the roll regeneration of large continuous rolling mills made of Cr5 forged steel

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Scrap Cr5 forged steel intermediate roll Specifications: Ф500×1550×4400mm

[0026] Regeneration target roll specification: Ф450×1430×4340mm. The hardness is required to be 93-97HSD, and the depth of the hardened layer is ≥25mm.

[0027] After appearance quality inspection, geometric size inspection, ultrasonic inspection and metallographic inspection, etc., it meets the regeneration requirements.

[0028] First, high temperature tempering treatment is carried out. First, the furnace temperature is raised to 250-300 °C and kept for 12 hours; then the temperature is raised to 680-700 °C at a rate of 50 °C per hour, and the temperature is kept for 15 hours. Then, air-cooled to room temperature to detect the regeneration target roller. The hardness is 35~38HSD;

[0029] After rough turning for two times of quenching and tempering, the specific process is:

[0030] The first quenching and tempering treatment: first raise the furnace temperature to 650-700°C and hold for 1...

Embodiment 2

[0035] Scrap Cr5 forged steel intermediate roll specification: Ф500×1550×4400mm, can a specification different from Example 1 be supplemented?

[0036] Regeneration target roll specification: Ф450×1430×4340mm. The hardness is required to be 93-97HSD, and the depth of the hardened layer is ≥25mm.

[0037] After appearance quality inspection, geometric size inspection, ultrasonic inspection and metallographic inspection, etc., it meets the regeneration requirements.

[0038] First carry out high temperature tempering treatment, first raise the furnace temperature to 250-300°C and keep for 14 hours; then raise the temperature to 680-700°C at a rate of 52°C per hour, keep the temperature for 15 hours, and then air-cool to room temperature to detect the regeneration target roller The hardness is 35~38HSD;

[0039] After rough turning for two times of quenching and tempering, the specific process is:

[0040] The first quenching and tempering treatment: first raise the furnace te...

Embodiment 3

[0045] Scrap Cr5 forged steel intermediate roll Specifications: Ф500×1550×4400mm

[0046] Regeneration target roll specification: Ф450×1430×4340mm. The hardness is required to be 93-97HSD, and the depth of the hardened layer is ≥25mm.

[0047] After appearance quality inspection, geometric size inspection, ultrasonic inspection and metallographic inspection, etc., it meets the regeneration requirements.

[0048] First carry out high temperature tempering treatment, first raise the furnace temperature to 250-300°C, and keep for 12 hours; then raise the temperature to 680-700°C at a rate of 55°C per hour, keep the temperature for 18 hours, and then air-cool to room temperature to detect the regeneration target roller The hardness is 35~38HSD;

[0049] After rough turning for two times of quenching and tempering, the specific process is:

[0050] The first quenching and tempering treatment: first raise the furnace temperature to 650-680°C and hold for 12 hours; then raise the ...

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Abstract

The invention provides a regeneration method of a scrapped Cr5 forged-steel working roller. The method comprises the steps of working roller detection, 680-700 DEG C high-temperature tempering process, twice quenching and tempering processes, and surface hardening process. In the twice quenching and tempering processes, first quenching and tempering comprises the steps that temperature is maintained at 940-980 DEG C for more than 12h and quenching is carried out; and temperature is maintained at 630-660 DEG C for 18-25h and tempering is carried out, wherein a target roller hardness is 35-45HSD; second quenching and tempering comprises the steps that temperature is maintained at 940-980 DEG C for more than 12h and quenching is carried out; and temperature is maintained at 630-660 DEG C for 18-25h and tempering is carried out, wherein a target roller hardness is 40-50HSD. With the steps, the scrapped Cr5 forged-steel working roller reaches application performances of a new roller. When the method provided by the invention is used in regeneration manufacturing of scrapped Cr5 forged-steel working roller, cost can be greatly saved.

Description

technical field [0001] The invention belongs to the field of materials and heat treatment, and relates to a method for regenerating cold-rolled work rolls, in particular to a method for selecting and regenerating scrap rolls, a heat treatment process and a method for X stress testing. Background technique [0002] As the steel industry continues to heat up, the demand for rolls has risen sharply. At present, the main material of cold-rolled work rolls (including intermediate rolls) at home and abroad is forged steel series with a Cr content of 5%, and a certain working layer thickness can be achieved by induction or overall quenching, especially the material of the entire roll is the same, through ESR and The forging technology ensures that the internal inclusion content, carbide distribution, porosity, segregation and other indicators are better. [0003] According to the manufacturing process, from smelting to spheroidizing hydrogen diffusion annealing, it is the preparat...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21D11/00C21D9/38C21D1/25C21D1/10
CPCY02P10/25
Inventor 彭辉张青孙大乐葛浩彬吴卫强印建军徐展顾晓辉
Owner BAOSHAN IRON & STEEL CO LTD
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