Vanadium-nitrogen microalloyed high-strength phase-transformation induced plastic steel seamless pipe and preparation method thereof

A phase change induced plasticity, seamless pipe technology, applied in the field of iron and steel, can solve the problems of inability to ensure uniform rotation of steel pipes, steel pipe specifications and length limitations, high cost of stainless steel, etc., to achieve easy control of the heating process, low manufacturing cost, and high heating speed stable effect

Active Publication Date: 2015-02-25
SHANDONG IRON & STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

With its advantages of good strength and elongation, phase transformation induced plasticity steel can solve the problem that the practical application of ordinary carbon steel seamless pipes has been limited in the field of internal high pressure forming due to the contradiction between strength and plasticity. question
[0003] At present, the relatively mature materials used in the field of internal high-pressure processing are still mainly low-strength steel pipes, titanium pipes, aluminum pipes, and magnesium pipes. These materials can be used to prepare T-shaped tees, Y-shaped tees, square pipes, corrugated Parts with complex cross-sectional shapes such as pipes, but the strength of these materials is generally low
In recent years, stainless steel has

Method used

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  • Vanadium-nitrogen microalloyed high-strength phase-transformation induced plastic steel seamless pipe and preparation method thereof
  • Vanadium-nitrogen microalloyed high-strength phase-transformation induced plastic steel seamless pipe and preparation method thereof
  • Vanadium-nitrogen microalloyed high-strength phase-transformation induced plastic steel seamless pipe and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] The chemical composition of the steel selected in this embodiment is C: 0.18%, Si: 1.52%, Mn: 1.41%, V: 0.17%, N: 0.01%, P: 0.008%, S: 0.004%, and the balance For Fe.

[0047] The smelted ingot is forged into a bar, the bar is turned to remove the outer surface wrinkles and defects to form a tube blank, and then the tube blank is heated to 1200°C and kept for 2 hours before piercing, and then cooled to room temperature; the cooled tube blank The tube blank is cold-drawn for 4 passes to obtain a seamless cold-drawn steel tube with a wall thickness of 1.5mm and an outer diameter of 44mm.

[0048] The seamless cold-drawn steel pipe is heated to the austenitization temperature range of 910-950°C with a medium-frequency heating induction coil at a heating rate of 35°C / s, and cooled with compressed air at a rate of about 60°C / s after annealing for 30-90s to 470-500°C in the bainite region, isothermally treated for 30-90s, and then naturally cooled to room temperature to obta...

Embodiment 2

[0055] The chemical composition of the steel used in this embodiment is C: 0.20%, Si: 1.0%, Mn: 1.20%, V: 0.19%, N: 0.018%, P: 0.019%, S: 0.005%, and the balance For Fe.

[0056] The smelted ingot is forged into a bar, the bar is turned to remove the outer surface wrinkles and defects to form a tube blank, and then the tube blank is heated to 1250°C and kept for 2 hours before piercing, and then cooled to room temperature; the cooled tube blank The tube blank is cold-drawn for 5 passes to obtain a seamless cold-drawn steel tube with a wall thickness of 2.3 mm and an outer diameter of 56 mm.

[0057] The seamless cold-drawn steel pipe is heated to the austenitization temperature range of 920-950°C with a medium-frequency heating induction coil at a heating rate of 30°C / s, and cooled with compressed air at a rate of about 50°C / s after annealing for 60-90s to 480-500°C in the bainite region, isothermally treated for 30-100s, and then naturally cooled to room temperature to obtai...

Embodiment 3

[0062] The chemical composition of steel selected in this embodiment is C: 0.21%, Si: 1.14%, Mn: 1.49%, V: 0.20%, N: 0.023%, P: 0.06%, S: 0.004%, and the balance For Fe.

[0063] The smelted ingot is forged into a bar, the bar is turned to remove the outer surface wrinkles and defects to form a tube blank, and then the tube blank is heated to 1250°C and kept for 3 hours before piercing, and then cooled to room temperature; the cooled tube blank The tube blank is cold-drawn 7 times to obtain a seamless cold-drawn steel tube with a wall thickness of 0.9 mm and an outer diameter of 1000 mm.

[0064] The seamless cold-drawn steel pipe is heated to the austenitization temperature range of 910-950°C with a medium-frequency heating induction coil at a heating rate of 35°C / s, and cooled with compressed air at a rate of about 60°C / s after annealing for 60-90s to 470-500°C in the bainite zone, isothermally treated for 30-100s, and then air-cooled to room temperature to obtain the phase...

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Abstract

The invention belongs to the steel technical field, and specifically, relates to a vanadium-nitrogen microalloyed high-strength phase-transformation induced plastic steel seamless pipe and a preparation method thereof. The vanadium-nitrogen microalloyed high-strength phase-transformation induced plastic steel seamless pipe comprises the chemical ingredients by the weight percentage: 0.18%-0.24% of C, 1.0%-1.6% of Si, 1.2%-1.6% of Mn, 0.17%-0.22% of V, 0.01%-0.03% of N, not more than 0.06% of P, not more than 0.005% of S, and the balance iron and unavoidable impurities. With utilization of an intermediate-frequency induction heat treatment device of a thin-wall steel pipe and with supplementary of a vanadium-nitrogen microalloyed component design, the advantage of cooperation of good strength and elongation of phase-transformation induced plastic steel is successfully applied to the steel pipe production field, a fact of replacing solid components with hollow components is effectively realized so as to achieve automobile light weighting, besides, further development of an internal high pressure forming technology is promoted, not only are the internal high pressure formed components with high strength, large deformation and complex shape produced, but also the production cost is greatly reduced, and the preparation method has wide application prospects are provided.

Description

technical field [0001] The invention belongs to the technical field of iron and steel. Specifically, the invention relates to a vanadium-nitrogen microalloy high-strength phase transformation-induced plasticity steel seamless pipe and a preparation method thereof. Background technique [0002] With the increasing global environmental and energy crisis, energy saving and emission reduction have become the primary issues facing the automobile manufacturing industry. It is still the development trend of the automobile industry to realize lightweight technology under the premise of ensuring the performance of the whole vehicle. Among them, through the use of hollow parts The application of replacing solid parts is one of the most effective ways to realize the lightweight of automobiles. With the maturity of high-pressure production technology in pipes, the industrial production of high-strength hollow components has become possible, and the realization of this scheme requires hi...

Claims

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Application Information

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IPC IPC(8): C22C38/12C21D8/10
CPCY02P10/20
Inventor 王业勤李海明陈永南张兴锦张兆萍侯晓英
Owner SHANDONG IRON & STEEL CO LTD
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