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A preparation method of ultra-high-strength nano-heterogeneous low-carbon steel

A technology for ultra-high-strength, low-carbon steel, applied in the field of preparation of ultra-high-strength nano-heterogeneous low-carbon steel, can solve the problems of low-strength low-carbon steel, and achieve low production costs, simple process flow, and simple production equipment Effect

Active Publication Date: 2021-09-10
NANJING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the grain size of dual-phase steel is on the order of microns, resulting in low-carbon steel still having low strength

Method used

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  • A preparation method of ultra-high-strength nano-heterogeneous low-carbon steel
  • A preparation method of ultra-high-strength nano-heterogeneous low-carbon steel
  • A preparation method of ultra-high-strength nano-heterogeneous low-carbon steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] A low-carbon steel ingot with a chemical composition of C 0.20%, Si 1.46%, Mn 1.01%, P 0.003%, S 0.001%, and the balance of Fe is selected.

[0022] (1) Ultrafine heat treatment:

[0023] a) Obtaining ultra-fine lamellar structure martensite: cut from a low-carbon steel ingot with the above chemical composition of C 0.20%, Si 1.46%, Mn 1.01%, P 0.003%, S 0.001%, and the balance is Fe A small piece with a size of 80mm×40mm×8mm is put into a vacuum furnace at 920°C for 1 hour and then water quenched to obtain a full martensitic structure with an ultrafine lamellar structure.

[0024] b) Obtain fibrous dual-phase structure: heat the fully martensitic sample to 820°C in a resistance furnace for 10 minutes and then water quench to obtain a fibrous ferrite-martensite dual phase with ultrafine layered structure organize.

[0025] (2) Nano-deformation: Roll the fibrous dual-phase structure at 300°C, and the amount of downforce per pass is 0.2mm. Before each pass, the sample i...

Embodiment 2

[0027] A 12 mm thick commercial Q195 steel plate with a chemical composition of C 0.12%, Si 0.25%, Mn 0.46%, P 0.005%, S 0.002% and the balance of Fe was selected.

[0028] (1) Ultrafine heat treatment:

[0029] a) Put the above-mentioned commercial Q195 steel plate whose chemical composition is C 0.12%, Si 0.25%, Mn 0.46%, P 0.005%, S 0.002% and the balance is Fe, into a vacuum furnace at 900°C for 1 hour and then water Quenching to obtain a full martensitic structure with an ultrafine lamellar structure.

[0030] b) Heat the fully martensitic sample in a resistance furnace to 780°C for 10 minutes and then quench it. The quenching medium is 10% NaCl solution to obtain a fibrous ferrite-martensite dual phase with an ultra-fine layered structure organize.

[0031] (2) Nano-deformation: rolling the fibrous dual-phase structure at 250°C, with a downforce of 0.2mm per pass, and heating the sample in a resistance furnace for 10 minutes before rolling each pass, and the cumulative...

Embodiment 3

[0033] A commercial Q235B steel plate with a chemical composition of C 0.16%, Si 0.22%, Mn 0.45%, P 0.004%, S 0.001%, and the balance of Fe is selected.

[0034] (1) Ultrafine heat treatment:

[0035] a) A 12 mm thick commercial Q235B steel plate with the above chemical composition of C 0.16%, Si 0.22%, Mn 0.63%, P 0.004%, S 0.001%, and the balance being Fe. , placed in a vacuum furnace at 900°C for 1 hour and then quenched. The quenching medium is 10% NaCl solution to obtain a full martensitic structure with an ultrafine lamellar structure.

[0036] b) Heating the fully martensitized sample to 780° C. for 10 minutes in a resistance furnace and quenching in water to obtain a fibrous ferrite-martensite dual-phase structure with an ultrafine layered structure.

[0037] (2) Nano-deformation: Roll the fibrous dual-phase structure at 300°C, and the amount of downforce per pass is 0.2mm. Before each pass, the sample is placed in a resistance furnace and heated for 10 minutes. The ...

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Abstract

The invention provides a preparation method of ultra-high-strength nano-heterogeneous low-carbon steel, which comprises two steps of heat treatment refinement and deformation refinement. It is characterized in that: firstly, an ultra-fine lath martensite structure is obtained by fully martensitizing an initial ferrite-pearlite low carbon steel, and then a critical zone heat treatment is performed on the fully martensitic structure. A fibrous dual-phase steel with ultrafine lamellae is obtained by refining by heat treatment. Finally, the fibrous dual-phase steel is warmly rolled with a large amount of deformation, which can refine the ferrite and martensite at the same time to achieve the purpose of deformation refinement. The ultra-high-strength nano-heterogeneous low-carbon steel with a sheet thickness of about 20 nm is finally obtained, and its tensile strength can reach more than 2 GPa.

Description

technical field [0001] The invention relates to the preparation of ferrite / martensite dual-phase heterogeneous materials, specifically a method for preparing ultra-high-strength nano-heterogeneous low-carbon steel. Background technique [0002] As the most common structural material, iron and steel materials are widely used in construction, transportation, petrochemical and other fields. Especially in the automobile manufacturing industry, steel materials are often used to manufacture car bodies and some important parts. In consideration of energy saving, emission reduction and automobile safety, automobile suppliers put forward higher requirements on the strength and toughness of steel materials for automobiles. This requirement aims to increase the strength level of steel materials to meet design requirements. Increasing carbon content is the most effective and economical way of strengthening steel materials, but increasing carbon content will also bring many disadvantag...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21D6/00C21D1/18C21D7/00
CPCC21D1/18C21D6/00C21D7/00C21D2211/001C21D2211/005
Inventor 周浩高波赖庆全潘志驿杨明陈雪飞肖礼容
Owner NANJING UNIV OF SCI & TECH