700MPa grade composite strengthening bainite steel and method for preparing same

A bainite steel and alloying technology, which is applied in metal rolling and other directions, can solve the problems of complex process and high energy consumption, and achieve the effects of improving yield strength, saving alloying costs, and good performance

Inactive Publication Date: 2008-10-15
GUANGZHOU PEARL RIVER STEEL & IRON
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the molten steel can only be cast after vacuum treatment after refining, and the billet needs to be coole

Method used

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  • 700MPa grade composite strengthening bainite steel and method for preparing same
  • 700MPa grade composite strengthening bainite steel and method for preparing same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] The main chemical components of molten steel after refining when preparing the 700MPa grade composite strengthened bainitic steel described in this example are: C: 0.03wt.%, Si: 0.30wt.%, Mn: 1.51wt.%, P: 0.006wt .%, S: 0.003wt.%, Cr: 0.50wt.%, Ti: 0.15wt.%, and the rest are Fe and unavoidable residual elements. The photo of the metallographic structure of the prepared 700MPa composite strengthened bainite steel can be found in figure 1 .

[0028] Rolling process parameters: billet entering soaking furnace temperature 900°C, furnace exit temperature 1100°C, final rolling temperature 870°C, coiling temperature 570°C. See Table 1 for the cooling rate control and mechanical properties of the steel plate after rolling.

[0029] Table 1 Example 1 steel plate cooling rate control and mechanical properties after rolling

[0030] Steel plate thickness

Embodiment 2

[0032] The main chemical components of molten steel after refining when preparing the 700MPa grade composite strengthened bainite steel described in this example are: C: 0.070wt.%, Si: 0.10wt.%, Mn: 1.85wt.%, P: 0.020wt .%, S: 0.010wt.%, Cr: 0.80wt.%, Ti: 0.12wt.%, and the rest are Fe and unavoidable residual elements.

[0033] Rolling process parameters: billet entering soaking furnace temperature 1000°C, furnace exit temperature 1180°C, final rolling temperature 930°C, coiling temperature 640°C. See Table 2 for the cooling rate control and mechanical properties of the steel plate after rolling.

[0034] Table 2 The cooling rate control and mechanical properties after rolling of the steel plate of Example 2

[0035] Steel plate thickness

Embodiment 3

[0037] The main chemical components of molten steel after refining when preparing the 700MPa grade composite strengthened bainitic steel described in this example are: C: 0.050wt.%, Si: 0.15wt.%, Mn: 2.10wt.%, P: 0.009wt .%, S: 0.003wt.%, Cr: 0.65wt.%, Ti: 0.10wt.%, and the rest are Fe and unavoidable residual elements.

[0038] Rolling process parameters: billet entering soaking furnace temperature 930°C, furnace exit temperature 1150°C, final rolling temperature 900°C, coiling temperature 590°C. See Table 3 for the cooling rate control and mechanical properties of the steel plate after rolling.

[0039] Table 3 Example 3 steel plate cooling rate control and mechanical properties after rolling

[0040] Steel plate thickness

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PUM

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Abstract

The invention discloses a 700MPa compound strengthening bainitic steel and a method for making the same. The compound strengthening bainitic steel is manufactured by adopting thin slab continuous casting and rolling process, wherein, the main chemical compositions in percentage by weight of the refined molten steel are: 0.03 to 0.07 percent of C , 1.51 to 2.10 percent of Mn, 0.50 to 0.80 percent of Cr, 0.10 to 0.15 percent of Ti, less than or equal to 0.30 percent of Si, less than or equal to 0.020 percent of P, less than or equal to 0.010 percent of S, the balance being Fe and inevitable residual elements. The invention realizes that the yield strength of the prior 345MPa hot-rolled sheet doubles and opens a new way to produce 700MPa high-strength steel by saving expensive alloying elements like Mo, Ni and so on. At the same time, the steel structure mainly comprises fine bainites, which improves the work hardening capacity of the high-strength steel and has a good forming property.

Description

technical field [0001] The invention belongs to the field of low-alloy steel manufacturing, and in particular relates to a low-carbon 700MPa grade composite strengthened bainite steel and a preparation method thereof. Background technique [0002] For the structural parts, welding parts and suspension parts of transportation equipment, increasing the strength of the steel plate to reduce the thickness of the steel plate can not only save the manufacturing cost, but also reduce the unit fuel consumption during the transportation process and significantly improve the transportation efficiency. Generally, the stability of the structure can be guaranteed by following the empirical formula corresponding to the relationship between the material and thickness of the structural member. [0003] t 1 t 2 = σ s ...

Claims

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Application Information

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IPC IPC(8): C22C38/38B21B1/46
Inventor 毛新平陈麒琳朱达炎
Owner GUANGZHOU PEARL RIVER STEEL & IRON
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