Production method of easily-shaped high-strength medium-thickness steel plate

A production method and technology for thick steel plates, which are applied in heat treatment equipment, heat treatment process control, manufacturing tools, etc., can solve problems such as difficulty in meeting actual use requirements, uncontrolled yield ratio, poor cold bending performance, etc. The effect of satisfying the bending performance, reducing the yield ratio and improving the welding performance

Active Publication Date: 2013-07-31
HUNAN VALIN XIANGTAN IRON & STEEL CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0011] In short, the high-strength steel plate produced by the traditional direct quenching + tempering process (DQ+T) has the following disadvantages: the elongation of the steel plate composition is less than 7%, the steel plate yield ratio is greater than 0.96; the steel plate yield ratio is high, and it is difficult to meet the actual design requirements. Requirements for use; the uniform elongation of the steel plate is low, and the fractu

Method used

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  • Production method of easily-shaped high-strength medium-thickness steel plate
  • Production method of easily-shaped high-strength medium-thickness steel plate
  • Production method of easily-shaped high-strength medium-thickness steel plate

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[0026] Example 1: Production method of 20mmQ890E steel plate

[0027] The chemical composition of steel is shown in Table 3.

[0028] Table 3 The actual composition of 20mm Q890E steel plate%

[0029] chemical compositionC Si MnPS Nb+V+ Ti Cr+ Mo Alt Pcm CEV Actual performance 0.080.201.690.0130.0010.1050.910.0320.250.58

[0030] Main process steps:

[0031] a. The sulphur content of the molten iron is S≤0.020%, and the temperature is ≥1250℃. The slag must be removed before the molten iron enters the converter. The target of converter end point control: CT coordinated tapping, P 0.013%, S 0.019%; strict slag tapping, slag thickness ≤50mm, tapping time 6min, tapping 1 / 5 with alloy, tapping 2 / 5 with alloy ; After tapping, drive into Al wire 260m for deoxidation.

[0032] b. The molten steel is energized for 22 minutes in the LF furnace, the total argon blowing time is 42 minutes, and the white slag retention time is 16 minutes. Feed the Al line and adjust Alt, the argon station ha...

Example Embodiment

[0038] Example 2: Production method of 30mm Q890E steel plate

[0039] The chemical composition of steel is shown in Table 4.

[0040] Table 4 The composition performance of 30mm Q890E steel plate%

[0041] chemical compositionC Si MnPS Nb+V+ Ti Cr+ Mo Alt Pcm CEV Actual performance 0.080.231.670.0130.0030.1100.930.0340.260.59

[0042] a. The sulphur content of the molten iron is S≤0.020%, and the temperature is ≥1250℃. The slag must be removed before the molten iron enters the converter. End point control target for converter: CT coordinated tapping, P 0.012%, S 0.016%; strict slag tapping, slag thickness ≤50mm, tapping time 6min, tapping 1 / 5 with alloy, tapping 2 / 5 with alloy ; After tapping, drive into Al wire 300m to deoxidize.

[0043] b. The molten steel is energized for 27 minutes in the LF furnace, the total argon blowing time is 44 minutes, and the white slag retention time is 15 minutes. Feed the Al line and adjust Alt, the argon station has finished processing molten...

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Abstract

The invention relates to a production method of an easily-shaped high-strength medium-thickness steel plate, which comprises the processing steps of converter steelmaking, ladle furnace refinement, vacuum treatment, continuous casting, heating, rolling, pre-straightening, on-line quenching and tempering heat treatment. The steel comprises the following components in percentage by mass: 0.07-0.09% of C, 0.15-0.30% of Si, 1.60-1.90% of Mn, no more than 0.015% of P, no more than 0.005% of S, no more than 0.12% of Nb+V+Ti, no more than 1.20% of Cr+Mo, no less than 0.020% of Alt, no more than 0.60% of CEV and no more than 0.27% of Pcm. The Q890E steel plate produced by the method has good 120mm-wide cold bending property, and the real cold bending property of the steel plate meets the requirements of users for easy shaping; the yield ratio of the steel plate is less than 0.92, and the uniform elongation rate is more than 8%, thus meeting the use requirements of related designs; the product of strength and elongation is increased by more than 35%, the dynamic load resistance of the high-strength steel plate is increased, and the safety of equipment is enhanced; the hot charging and on-line quenching of a continuous casting billet reduce the production cost; and the component design (the percentage of Pcm is no more than 0.27%) increases the welding property of the high-strength steel plate.

Description

technical field [0001] The invention belongs to steelmaking technology, and is a production method of easy-to-form high-strength medium-thick steel plate. Background technique [0002] With the development of the metallurgical industry, the production of high-strength steel plates with a yield of more than 550MPa has undergone tremendous changes, from the traditional reheating quenching + tempering (ie RQ+T) process to TMCP, TMCP+T, DQ+T, Q+ P, Q+P+T, especially in recent years, the on-line direct quenching (Direct Quenching, DQ for short) process after rolling has made great progress and is widely used in the production of high-strength steel plates. [0003] Compared with the high-strength structural steel produced by other processes, the high-strength structural steel produced by the DQ process can greatly reduce the content of alloy elements and reduce the carbon equivalent under the condition of equivalent mechanical properties, improve the performance of welding and ot...

Claims

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Application Information

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IPC IPC(8): C22C38/06C22C38/12C22C38/14C22C38/38C21D8/02C21D11/00C21D1/18
Inventor 杨云清曹志强刘建兵吴清明杜江张青学田勇李玉路王东梅谭小斌高海亮史志凌闻国院
Owner HUNAN VALIN XIANGTAN IRON & STEEL CO LTD
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