Production technology of improved bolt

A production process and bolt technology, applied in the field of nuclear power bolt production process, can solve the problems that the production process cannot meet the requirements, and the requirements of strength, hardness and impact resistance are very strict, and achieve good lubricity, strong anti-corrosion ability, and phosphating. fine film effect

Inactive Publication Date: 2019-06-11
NINGBO QUNLI FASTENER MFG CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, the fasteners used in nuclear power equipment are very demanding in terms of strength, hardness and impact resistance. Fo

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] The production process of nuclear power bolts, the technological process is blank preparation-heat treatment-flaw detection inspection-surface treatment.

[0023] Using 42CrMoE steel as raw material, the chemical composition mass percentage is: C content 0.405%, Si content 0.23%, Mn content 0.78%, P content 0.012%, S content 0.013%, Cr content 0.94%, Mo content 0.17%, the balance is Fe. Raw material production inspection, blanking, plane chamfering, heat treatment, thread blank diameter grinding, thread rolling.

[0024] The heat treatment process quenches and tempers bolts < 0.5M and bolts ≥ 0.5M respectively. Bolts with a length of less than 0.5M are quenched in a mesh belt furnace with alloy steel quenching oil as the medium, the quenching temperature is 850°C, and the holding time is 2 hours. After quenching, continue tempering in the mesh belt furnace, the tempering temperature is 680°C, and the holding time is 2.5 hours.

[0025] Bolts with a length ≥ 0.5M are ...

Embodiment 2

[0028] The raw materials and process flow of this embodiment are the same as those in Embodiment 1, except that in the heat treatment process, for bolts with a length <0.5M, the quenching temperature is 860° C., and the holding time is 2 hours. After quenching, continue tempering in the mesh belt furnace, the tempering temperature is 630°C, and the holding time is 2.5 hours.

[0029] Bolts with a length ≥ 0.5M are quenched in a pit furnace with mechanical oil as the medium, the quenching temperature is 860°C, and the holding time is 2.5 hours. After quenching, continue to temper in the pit furnace, the tempering temperature is 630°C, and the time is 3 hours.

Embodiment 3

[0031] The process flow of this embodiment is the same as that of Embodiment 1, the difference is the raw materials and heat treatment process.

[0032] Using 42CrMoE steel as raw material, the chemical composition mass percentage is: C content 0.38%, Si content 0.10%, Mn content 0.75%, P content 0.025%, S content 0.015%, Cr content 0.80%, Mo content 0.15%, the balance is Fe.

[0033] For bolts with a length less than 0.5M, the quenching temperature is 860°C and the holding time is 2 hours. After quenching, continue tempering in the mesh belt furnace, the tempering temperature is 620°C, and the holding time is 2.5 hours.

[0034] Bolts with a length ≥ 0.5M are quenched in a pit furnace with mechanical oil as the medium, the quenching temperature is 860°C, and the holding time is 2.5 hours. After quenching, continue to temper in the pit furnace, the tempering temperature is 620°C, and the time is 3 hours.

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Abstract

The invention mainly discloses a production technology of an improved bolt. The production technology comprises the steps that 42CrMoE rolled steel is adopted as a raw material, a blank is prepared, heat treatment is conducted, surface treatment is conducted, and defectoscopy is conducted, wherein the raw material 42CrMoE comprises the chemical components in percentage by mass: 0.38%-0.48% of C, 0.10%-0.40% of Si, 0.75%-1.00% of Mn, smaller than or equal to 0.025% of P, smaller than or equal to 0.015% of S, 0.80%-1.15% of Cr, 0.15%-0.30% of Mo, and the balance of Fe. According to the production technology of the improved bolt, products obtained through the technology meet the requirements of nuclear power first-level equipment, nuclear power second-level equipment and nuclear power third-level equipment, and the strength, the hardness and impact resistance are all up to the standard.

Description

technical field [0001] The invention relates to a production process of fasteners, in particular to a nuclear power bolt production process meeting the requirements of nuclear power level 1, 2 and 3 equipment. Background technique [0002] A nuclear power plant is a power facility that uses the thermal energy generated by one or several power reactors to generate electricity or generate electricity and heat. The fuel used in nuclear power plants is uranium. The nuclear fuel made of uranium is fissioned in the "reactor" equipment to generate a large amount of heat energy, and then the water under high pressure is used to take out the heat energy and generate steam in the steam generator. Push the steam turbine to rotate together with the generator, and electricity is continuously generated and sent to all directions through the grid. [0003] In order to ensure the safety of nuclear power plants, the strictest defense measures conceivable should be taken in terms of design a...

Claims

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Application Information

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IPC IPC(8): C22C38/02C22C38/04C22C38/22C21D1/18C21D9/00C23C22/18B23P15/00
Inventor 施仑吴日旺
Owner NINGBO QUNLI FASTENER MFG CO LTD
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