Heat-resistant steel sheet for power station boiler and manufacturing method thereof

A technology for power plant boilers and manufacturing methods, applied in the field of heat-resistant steel plates for power plant boilers, can solve problems such as poor plasticity, easy cracking, poor thermoplasticity, etc., achieve the effects of reducing quantity and grade, eliminating surface cracks, and improving comprehensive performance

Active Publication Date: 2015-05-06
SHANXI TAIGANG STAINLESS STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Heat-resistant steel for power plant boilers can be used as boiler heating surface structure due to its high oxidation resistance, high temperature steam corrosion resistance, good impact toughness and durable plasticity In the field of parts, the generation of δ ferrite in the existing heat-resistant steel plate for power plant boilers, the thermoplasticity of the material is poor, the slab cracks during the rolling process, and the comprehensive mechanical properties of the material cannot meet the requirements for use
[0003]Because the heat-resistant steel used in power plant boilers is high-alloy steel with high degree of alloying, increased deformation resistance, narrow hot-working temperature range, and poor plasticity, during hot-working It is easy to crack after medium and rolling, especially the production of wide medium and heavy plates is extremely difficult
At present, there is no domestic company that can produce heat-resistant steel plates for power plant boilers with a thickness of 20-40 mm and a width of 2000-3000 mm. This steel has been monopolized by foreign companies for a long time, and no public reports have been found.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] The size specification of the heat-resistant steel plate for power plant boilers is 20mm in thickness and 2000mm in width, and the mass percentage of its chemical composition is: C 0.087%, Si 0.22%, Mn 0.51%, P 0.012%, S 0.001%, Cr 8.74%, Mo 0.38% , V 0.18%, W 1.63%, Nb 0.051%, N 0.061%, B 0.0024%, Ni 0.25%, Al 0.004%, O 18ppm, and the rest are Fe and unavoidable impurities.

[0044] Flaw detection requirements: flaw detection level ≤ II

[0045] Mechanical property requirements: yield strength R p0.2 ≥440MPa, tensile strength R m ≥620MPa, elongation A≥20%, normal temperature impact energy A KV2 ≥90J;

[0046] Plate type requirements: unevenness in the width direction of the steel plate ≤ 5mm / m.

[0047] This embodiment includes the following steps in sequence:

[0048] Ⅰ Billet preparation

[0049] After molten iron pretreatment, 180-ton converter top and bottom blowing, AOD and LF refining, the mass percentage of chemical composition meets the following requirem...

Embodiment 2

[0071] The size specification of the heat-resistant steel plate for power plant boilers is 40mm in thickness and 3000mm in width, and the mass percentage of its chemical composition is: C 0.089%, Si 0.24%, Mn 0.51%, P 0.011%, S 0.003%, Cr 8.74%, Mo 0.38% , V 0.17%, W 1.65%, Nb 0.053%, N 0.065%, B 0.0032%, Ni 0.27%, Al 0.005%, O 16ppm, and the rest are Fe and unavoidable impurities.

[0072] Flaw detection requirements: flaw detection level ≤ II

[0073] Mechanical property requirements: yield strength R p0.2 ≥440MPa, tensile strength R m ≥620MPa, elongation A≥20%, normal temperature impact energy A KV2 ≥90J;

[0074] Plate type requirements: unevenness in the width direction of the steel plate ≤ 5mm / m.

[0075] This embodiment includes the following steps in sequence:

[0076] Ⅰ Billet preparation

[0077] After molten iron pretreatment, 180-ton converter top and bottom blowing, AOD and LF refining, the mass percentage of chemical composition meets the following requirem...

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Abstract

The invention relates to a heat-resistant steel sheet for a power station boiler and a manufacturing method thereof. The steel sheet comprises the following components in percentage by mass: 0.08-0.12% of C, 0.15-0.45% of Si, 0.35-0.55% of Mn, less than or equal to 0.013% of P, less than or equal to 0.005% of S, 8.60-8.90% of Cr, 0.31-0.50% of Mo, 0.16-0.22% of V, 1.55-1.85% of W, 0.045-0.085% of Nb, 0.045-0.065% of N, 0.002-0.004% of B, 0.20-0.35% of Ni, greater than 0 and less than or equal to 0.01% of Al and greater than 0 and less than or equal to 20ppm of O. The performance of the steel sheet reaches the application requirements and the width of the steel sheet reaches 2000-3000 mm. The manufacturing method sequentially comprises the following steps: preparing billet materials, casting a continuous casting billet; annealing at an annealing temperature of 740 + / -10 DEG C; carrying out hot grinding; heating the steel billet at a heating temperature of 1230 + / -10 DEG C; (V) rolling at a rough-rolling starting temperature of 1160-1200 DEG C and the finish rolling temperature of 860-900 DEG C; (VI) carrying out heat straightening; (VII) normalizing at a normalizing temperature of 1050 + / -10 DEG C; and (VIII) tempering at a tempering temperature of 780 + / -10 DEG C, carrying out heat preservation, discharging the steel sheet out of a furnace and carrying out air cooling. The manufacturing method is high in finished product rate and low in cost.

Description

technical field [0001] The invention relates to a heat-resistant steel plate for power plant boilers and a manufacturing method of the steel plate. Background technique [0002] Due to its high oxidation resistance, high temperature steam corrosion resistance, good impact toughness and long-lasting plasticity, heat-resistant steel for power plant boilers can be used in the field of boiler heating surface structural parts. The δ iron in the existing heat-resistant steel plates for power plant boilers The generation of the body, the thermoplasticity of the material is poor, the slab cracks during the rolling process, and the comprehensive mechanical properties of the material cannot meet the requirements for use. [0003] Because the heat-resistant steel used in power plant boilers is high-alloy steel, with high alloying degree, increased deformation resistance, narrow thermal processing temperature range, and poor plasticity, it is easy to crack during thermal processing and ...

Claims

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Application Information

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IPC IPC(8): C22C38/54C22C33/04C21D8/02
Inventor 赵振铎潘小娟陈金虎王育田范光伟
Owner SHANXI TAIGANG STAINLESS STEEL CO LTD
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