High-strength corrosion-resistant composite chequered iron and manufacturing method therefor

Abstract

Disclosed are a high-strength corrosion-resistant cladding chequered steel and a manufacturing method therefor. The high-strength corrosion-resistant cladding chequered steel includes a substrate and a chequered cladding layer cladded on the substrate by single-sided or double-sided rolling. The mass percentages of the chemical elements of the substrate are: C: 0.01% to 0.20%, Si: 0.10% to 0.5%, Mn: 0.5% to 2.0%, Al: 0.02% to 0.04%, Ti: 0.005% to 0.018%, Nb: 0.005% to 0.020%, 0<B≤0.0003%, N≤0.006%, and the balance being steel and other inevitable impurities. The high-strength corrosion-resistant cladding steel plate has a high strength, a high corrosion resistance, a yield strength ≥470 MPa, a tensile strength ≥610 MPa, a shear strength ≥410 MPa, and an elongation ≥40%.

Claims

1. A high-strength corrosion-resistant cladding chequered steel comprising a substrate and at least one chequered cladding layer cladded onto the substrate by rolling, wherein the at least one chequered cladding layer comprises a surface pattern applied thereto by a patterned roller, and the substrate comprises the following chemical elements in mass percentage: C: 0.01% to 0.20%, Si: 0.10% to 0.5%, Mn: 0.5% to 2.0%, Al: 0.02% to 0.04%, Ti: 0.005% to 0.018%, Nb: 0.005% to 0.020%, 0<B<0.0003%, N<0.006%, and the balance being iron and other inevitable impurities; wherein the substrate further comprises at least one of Ni, Cr and Mo in mass percentage: Ni<0.20%, Cr<0.20%, and Mo<0.10%; and wherein the thickness of the at least one chequered cladding layer is in a range of 10% to 40% of the thickness of the high-strength corrosion-resistant cladding chequered steel.

2. The high-strength corrosion-resistant cladding chequered steel according to claim 1, wherein the at least one chequered cladding layer is an austenitic stainless steel.

3. The high-strength corrosion-resistant cladding chequered steel according to claim 1, wherein the substrate has a microstructure of ferrite plus pearlite.

4. The high-strength corrosion-resistant cladding chequered steel according to claim 1, wherein there is a transition layer at a joint of the substrate and the at least one chequered cladding layer, and wherein the transition layer has a thickness of 200 μm or less.

5. The high-strength corrosion-resistant cladding chequered steel according to claim 1, wherein the steel has a yield strength of 470 MPa or more, a tensile strength of 610 MPa or more, and a shear strength of 410 MPa or more.

6. A method for manufacturing the high-strength corrosion-resistant cladding chequered steel according to claim 1, comprising the steps of: (1) producing a substrate blank and a cladding layer blank; (2) assembling the substrate blank and the cladding layer blank, obtaining a billet, and welded sealing all around the bonding surface of each layer, and then vacuuming; (3) clad rolling: the billet is first heated at a temperature of 1100˜1180° C., and then multi-pass rolled, obtaining a cladding steel sheet, wherein the total reduction is not less than 70% and the final rolling temperature is not less than 900° C., a surface chequer is rolled in a last pass of the multi-pass rolling, wherein the reduction in the last pass is 10%˜20%; (4) coiling after water-cooling.

7. The method according to claim 6, wherein, in the step (3), the final rolling temperature is controlled to 920˜1000° C.

8. The method according to claim 6, wherein, in the step (4), the coiling temperature is 500˜650° C.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows the metallographic structure of the high-strength corrosion-resistant cladding chequered steel of Example 1 under a low power microscope.

(2) FIG. 2 is a photograph showing the metallographic structure of the substrate of the high-strength corrosion-resistant cladding chequered steel of Example 1.

(3) FIG. 3 is a photograph showing the metallographic structure of the transition layer on one side between the substrate and the chequered cladding layer of the high-strength corrosion-resistant cladding chequered steel of Example 1.

(4) FIG. 4 is a photograph showing the metallographic structure of the transition layer on another side between the substrate and the chequered cladding layer of the high-strength corrosion-resistant cladding chequered steel of Example 1.

(5) FIG. 5 is a schematic view showing the pattern of the surface chequer in the cladding layer of the high-strength corrosion-resistant cladding chequered steel of Example 1.

(6) FIG. 6 is a schematic view showing the structure of the surface chequer in the cladding layer of the high-strength corrosion-resistant cladding chequered steel of Example 1 from another viewing angle.

DETAILED DESCRIPTION

(7) The high-strength corrosion-resistant cladding chequered steel and the manufacturing method thereof according to the present invention will be further explained and illustrated below with reference to the accompanying drawings and specific Examples. However, the explanations and illustrations do not unduly limit the technical solutions of the present invention.

Examples 1˜4

(8) Table 1 lists the mass percentage of the chemical elements in each layer of the high-strength corrosion-resistant cladding chequered steels of Examples 1˜4.

(9) TABLE-US-00001 TABLE 1 (wt %, the balance is Fe and other inevitable impurity elements other than P and S) Example Layer C Si Mn P S Al Ti Nb Ni Cr Mo B N 1 Cladding layer 304 stainless steel Substrate 0.1 0.35 1.5 0.01 0.005 0.04 0.018 0.02 — — 0.1 0.00028 0.0045 2 Cladding layer 304L stainless steel Substrate 0.14 0.25 1 0.01 0.005 0.03 0.014 0.011 — 0.2 — 0.0003 0.0052 3 Cladding layer 316 stainless steel Substrate 0.2 0.15 0.5 0.008 0.004 0.02 0.005 0.005 — — — 0.0003 0.004 4 Cladding layer 316L stainless steel Substrate 0.11 0.3 1.48 0.008 0.005 0.026 0.008 0.018 0.1 — — 0.00028 0.0038

(10) The high-strength corrosion-resistant cladding chequered steels of Examples 1˜4 were prepared by the following steps (See Table 2 for specific process parameters for each Example):

(11) (1) a substrate blank and a cladding blank was produced according the chemical composition listed in Table 1;

(12) (2) the substrate blank and the cladding blank was assembled to obtain an billet, and all around of bonding surface of each layer were welded, sealed and then the space between the two layers was vacuumed;

(13) (3) clad rolling: the assembly was first heated at a temperature of 1100˜1180° C., and then multi-pass rolled to obtain a cladding steel sheet, wherein the total reduction rate was not less than 70% and the final rolling temperature was 920˜1000° C., a surface chequer was rolled in the last pass of the multi-pass rolling, wherein the reduction rate in the last pass is 10%-20%;

(14) (4) coiling after water-cooling, wherein the coiling temperature is 500˜650° C.

(15) Table 2 lists the specific process parameters in the manufacturing method of the high-strength corrosion-resistant cladding chequered steels of Examples 1˜4.

(16) TABLE-US-00002 TABLE 2 Cladding Blank Heating Steel sheet Chequered Final rolling Total Coiling Reduction Substrate layer structure of temperature thickness cladding layer tempeature reduction temperature in last micro- micro- Example the billet (° C.) (mm) thickness (mm) (° C.) (%) (° C.) pass (%) structure structure 1 cladding 1150 6 1.02 980 97 600 10 ferrite + Austenite layer + pearlite substrate + cladding layer 2 cladding 1160 5 0.8 1000 98 655 12 ferrite + Austenite layer + pearlite substrate + cladding layer 3 cladding 1140 4 0.5 990 98 550 10 ferrite + Austenite layer + pearlite substrate + cladding layer 4 cladding 1180 5 1 980 97 580 15 ferrite + Austenite layer + pearlite substrate + cladding layer

(17) Table 3 lists the test results of the high-strength corrosion-resistant cladding chequered steels of Examples 1˜4 in various performance tests.

(18) TABLE-US-00003 TABLE 3 Yield Tensile cold bend Shear strength strength Elongation radius strength Example (MPa) (MPa) (%) (180°) (MPa) 1 472 611 35.8 0.7 a 420 2 507 649 36.0 0.7 a 410 3 480 650 40.0 0.7 a 415 4 482 638 38.0 0.7 a 422

(19) As can be seen from Table 3, Examples 1˜4 exhibited a yield strength of 470 MPa or more, a tensile strength of 610 MPa or more, a shear strength of 410 MPa or more, and an elongation of 40% or more, indicating that the Examples of the present invention had high strength and excellent mechanical properties.

(20) FIG. 1 shows the metallographic structure of the high-strength corrosion-resistant cladding chequered steel of Example 1 under a low power microscope. As shown in FIG. 1, the high-strength corrosion-resistant cladding chequered steel of Example 1 had a chequered cladding layer 1 and a substrate 2.

(21) FIG. 2 is a photograph showing the metallographic structure of the substrate of the high-strength corrosion-resistant cladding chequered steel of Example 1. As shown in FIG. 2, the structure of the substrate was ferrite and pearlite, wherein grains in the microstructure was fine and uniform, and the average grain size of ferrite is 10 μm or less.

(22) FIG. 3 is a photograph showing the metallographic structure of the transition layer on one side between the substrate and the chequered cladding layer of the high-strength corrosion-resistant cladding chequered steel of Example 1. As shown in FIG. 3, there was a transition layer 12 between the substrate 13 and the chequered cladding layer 11 of Example 1.

(23) FIG. 4 is a photograph showing the metallographic structure of the transition layer on another side between the substrate and the chequered cladding layer of the high-strength corrosion-resistant cladding chequered steel of Example 1. As shown in FIG. 4, there was a transition layer 22 between the substrate 13 and the chequered cladding layer 21 of Example 1.

(24) As can be seen from FIG. 3 and FIG. 4, in Example 1, there was a transition layer between the substrate and the chequered cladding layer cladded on the substrate by double-sided rolling. The transition layers 12, 22 improve the bonding strength between the substrate 13 and the chequered cladding layers 11, 21; as a result, Example 1 was not easy to delaminate and crack.

(25) FIG. 5 is a schematic view showing the pattern of the surface chequer in the cladding layer of the high-strength corrosion-resistant cladding chequered steel of Example 1. As shown in FIG. 5, the surface pattern of Example 1 was a lenticular shape.

(26) FIG. 6 is a schematic view showing the structure of the surface chequer in the cladding layer of the high-strength corrosion-resistant cladding chequered steel of Example 1 from another viewing angle. As shown in FIG. 6, the height “h” of the surface chequer of Example 1 was 1.02 mm.

(27) It should be noted that the above are merely illustrative of specific Examples of the invention. It is obvious that the present invention is not limited to the above Examples, but has many similar variations. All modifications that are directly derived or associated by those skilled in the art are intended to be within the scope of the present invention.