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A process for quenching and tempering aisi4140 and aisi4340 structural steel forgings with one heat cycle

A process method and technology of structural steel, applied in the field of shaft forging manufacturing, can solve the problems of long manufacturing cycle, increased tendency of oxidation and decarburization of forging surface, and high manufacturing cost

Active Publication Date: 2016-01-20
HENAN ZHONGYUAN SPECIAL STEEL EQUIP MFG CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Not only the manufacturing cycle is long, but at the same time more than two thermal cycles are required, which increases the tendency of oxidation and decarburization on the surface of the forging, and the manufacturing cost is high

Method used

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  • A process for quenching and tempering aisi4140 and aisi4340 structural steel forgings with one heat cycle
  • A process for quenching and tempering aisi4140 and aisi4340 structural steel forgings with one heat cycle
  • A process for quenching and tempering aisi4140 and aisi4340 structural steel forgings with one heat cycle

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Experimental program
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Effect test

Embodiment 1

[0015] For AISI4140 forgings with a delivery specification of Φ500×5800, a deformation margin of 30-100mm is reserved in the last forging, and the forging temperature is controlled at 700-800°C for the elongation process to obtain the required shape and size. After forging Air-cool to 450-550°C on the surface of the forging, then enter the furnace at 650±50°C for 0.6-1.0h / 100mm heat preservation, hang it for air cooling or fog cooling after heat preservation, and put it into the furnace at this temperature after cooling to 300-400°C 0.8~1.5h / 100mm for heat preservation, after heat preservation, it rises to 850±50℃, at this temperature press

[0016] 0.6~1.0h / 100mm for uniformity, 0.6~1.0h / 100mm for heat preservation, after the heat preservation is completed, it is quenched, and it is quenched by intermittent air cooling-water cooling, and then 1.5~2.5h / 100mm at 500±50℃ respectively After keeping warm, air cool.

Embodiment 2

[0018] For AISI4340 forgings with a delivery specification of Φ400×5800, a deformation margin of 60-120mm is reserved in the last fire forging, and the forging temperature is controlled at 750-850°C for the elongation process to obtain the required shape and size. After forging Air-cool to 500-550°C on the surface of the forging, then enter the furnace at 650±50°C for 0.8-1.2h / 100mm heat preservation, hang it for air cooling or fog cooling after heat preservation, and put it into the furnace after cooling to 300-400°C 1.0~1.5h / 100mm for heat preservation, after heat preservation, rise to 850±50°C, 0.8~1.2h / 100mm for uniform temperature, 0.8~1.2h / 100mm for heat preservation, after heat preservation, it is out of the furnace and quenched, using intermittent air cooling-water cooling Quenching is carried out, and then at 550±50°C, heat preservation is carried out according to 2.0~2.5h / 100mm respectively, and then air-cooled.

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Abstract

The invention belongs to the technical field of shaft forged piece manufacturing and particularly relates to a technological method for AISI4140 and AISI 4340 constructional steel forged piece quenching and tempering through one-time thermal cycling, wherein the technological method is used for quenching and tempering of large-size forged pieces through one-time thermal cycling, shortens the manufacturing period and reduces the manufacturing cost. The method comprises the following steps that firstly, temperature-control forging is conduced; secondly, post-forging annealing and quenching and tempering treatment are conducted through heat generated after forging. The technological method for AISI4140 and AISI 4340 constructional steel forged piece quenching and tempering through one-time thermal cycling has the advantages that by adoption of the technological method, the forging heat is used for following-up post-forging hydrogen diffusion annealing and quenching and tempering heat treatment, the objective that quenching and tempering treatment is completed through one-time thermal cycling is achieved, the mechanical property of the product generated after quenching and tempering treatment according to the technological method is comparable to that of a product generated after quenching and tempering treatment conducted after rough machining.

Description

technical field [0001] The invention belongs to the technical field of manufacturing shaft forgings, and in particular relates to a process for quenching and tempering large-scale forgings by using one heat cycle, shortening the manufacturing cycle and reducing manufacturing costs. Background technique [0002] The traditional manufacturing process for quenching and tempering of large-scale shaft forgings adopts heat treatment after forging, and then quenching and tempering after rough machining. Not only the manufacturing period is long, but at the same time more than two thermal cycles are required, which increases the tendency of oxidation and decarburization on the surface of the forging, and the manufacturing cost is high. The invention directly performs hydrogen expansion annealing + quenching and tempering treatment after forging, and adopts one heat cycle for quenching and tempering, which can not only reduce the manufacturing cost, but also shorten the process flow,...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21D8/00C21D1/25
Inventor 王立新刘岩姚伟高全德孙振环田建宁薛正国
Owner HENAN ZHONGYUAN SPECIAL STEEL EQUIP MFG CO LTD