A method for manufacturing a 500mpa grade stainless steel composite steel plate u-rib plate unit

Abstract

The application discloses a kind of preparation methods of 500MPa grade stainless steel composite steel plate U rib plate unit, the method includes the following steps: selecting 500MPa grade stainless steel composite steel plate as bridge deck slab;U rib is positioned and welded on bridge deck slab;Bridge deck slab is preformed;U rib is welded;Bridge deck slab is cold straightening and fire straightening;Bridge deck slab is trimmed, and the 500MPa grade stainless steel composite steel plate U rib plate unit is obtained;The present application solves the problem of straightening difficulty of 500MPa grade stainless steel composite plate face plate U rib plate unit in the preparation process through preforming, welding, cold straightening and fire straightening etc. Operation, the high-precision production of 500MPa grade stainless steel composite steel plate U rib plate unit is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-strength stainless steel composite steel structure manufacturing, in particular to a preparation method of a 500MPa-grade stainless steel composite steel plate U-ribbed plate unit. BACKGROUND

[0002] The main materials of bridges are concrete and steel, and the problem of corrosion and rust needs to be considered during the use of steel. Traditional rust-proof paint is obviously not enough to protect the bridge surface under the current high-strength road surface use condition and the design service life of nearly a hundred years. The stainless steel composite steel plate can solve the long-term corrosion problem of the bridge surface, improve the service life of the bridge, and reduce the maintenance cost, because it not only maintains the original high strength, plasticity, toughness, weldability and fatigue resistance of alloy steel, but also has good corrosion resistance of stainless steel. It is widely used in the manufacture of railway steel bridge deck plates.

[0003] The U-ribbed plate is an important part of building bridges and plays a key role in bearing and transmitting loads. A standard U-ribbed plate unit is generally composed of six U-ribs and a deck plate, and the plate unit is 3.6-4 meters wide and 12-20 meters long. After welding, the U-ribbed plate unit needs to be corrected for deformation caused by welding to ensure that the flatness of the plate unit meets the standard. Bridge steel plate units made of ordinary Q420q and below can be used for high-temperature fire correction up to 800℃, because these materials are relatively simple and have high tolerance to welding deformation during welding. However, high-strength stainless steel composite steel plates, such as 500MPa-grade stainless steel composite steel plates composed of S31603+Q500qE, are prone to delamination at the bonded part when fire correction is performed at a high temperature due to the difference in thermal expansion coefficient. In addition, high temperature can cause the strength of Q500qE steel to decrease sharply. If low-temperature correction is used, the effect is not ideal and the plate surface may not be flat. Therefore, the traditional welding and correction method of U-ribbed plate units cannot be directly used for the manufacture of high-strength stainless steel composite steel plate U-ribbed plate units. SUMMARY

[0004] The present application discloses a preparation method of a 500MPa-grade stainless steel composite steel plate U-ribbed plate unit, which solves the problem of the difficulty of using ordinary correction methods for 500MPa-grade stainless steel composite steel plate U-ribbed plate units.

[0005] To achieve the above-mentioned purpose, the present application provides a preparation method of a 500MPa-grade stainless steel composite steel plate U-ribbed plate unit, comprising the following steps:

[0006] (1) selecting a 500MPa-grade stainless steel composite steel plate as a deck plate;

[0007] (2) positioning and welding U-ribs on the deck plate to obtain an assembled U-ribbed plate unit;

[0008] (3) pre-deforming the assembled U-rib plate unit to obtain a deformed U-rib plate unit;

[0009] (4) welding between the U-rib and the bridge deck plate on the deformed U-rib plate unit to obtain a welded U-rib plate unit;

[0010] (5) cold straightening the welded U-rib plate unit, and then using fire straightening to assist the straightening to obtain a straightened U-rib plate unit;

[0011] (6) edge cutting the straightened U-rib plate unit to obtain the 500MPa-grade stainless steel composite steel plate U-rib plate unit.

[0012] The preparation method can straighten and flatten the 500MPa-grade stainless steel composite steel plate U-rib plate unit through pre-deformation and symmetrical welding, mechanical straightening to complete preliminary straightening of the plate unit, and appropriate fire straightening temperature to assist the cold straightening.

[0013] On the basis of the above technical scheme, the application can also be improved as follows:

[0014] Preferably, the 500MPa-grade stainless steel composite steel plate is composed of a base layer and a stainless steel layer.

[0015] Preferably, the base layer is a Q500qE steel plate, and the chemical composition of the Q500qE steel plate is as follows: C≤0.11%, Si≤0.55%, Mn: 1.0~1.7%, P≤0.02%, S≤0.01%, Cr≤0.8%, Ni≤0.7%, Mo≤0.3%, and the balance is Fe and inevitable impurities; the stainless steel layer is an S31603 stainless steel plate, and the chemical composition of the S31603 stainless steel plate is as follows: C≤0.03%, Si≤0.75%, Mn≤2%, P≤0.045%, Cr: 16~18%, Ni: 10~14%, Mo: 2~3%, and the balance is Fe and inevitable impurities.

[0016] Preferably, the thickness of the Q500qE steel plate is 19.5~20.5mm, and the thickness of the S31603 stainless steel plate is 2.5~3.5mm.

[0017] Preferably, the Q500qE steel plate and the S31603 stainless steel plate are combined into a composite steel plate through explosive welding, and the U-rib is welded on one side of the Q500qE steel plate.

[0018] Preferably, the positioning welding comprises the following steps: drawing 6 groups of U rib assembly position lines on the bridge deck slab, the distance between the groups being 250-300 mm, numbering the U rib assembly position lines, the first, second, third, fourth, fifth and sixth groups of U rib assembly position lines being numbered from left to right, and welding the U ribs on the U rib assembly position lines.

[0019] Preferably, the welding method of the positioning welding is CO2 gas shielded welding using solid wire ER69-G, Φ=1.0, the welding current being 200-220 A, the welding voltage being 26-28 V, the welding speed being 550-600 mm / min, the length of a single positioning weld being 40-80 mm, and the distance between the welding points being 200-400 mm.

[0020] The preferred scheme has the beneficial effect that the use of 1.0 diameter welding wire for positioning welding can better ensure the welding penetration; the limitation of the length of the positioning weld and the welding points can avoid large workload and poor welding quality caused by too dense welding, and can better constrain the U rib to prevent the U rib from being bent sideways during subsequent weld welding.

[0021] Preferably, the welds are welded simultaneously and in the same direction according to the order of the third and fifth groups, the second and fourth groups, and the first and sixth groups of U rib assembly position lines.

[0022] The preferred scheme has the beneficial effect that the welding sequence is symmetrical left and right, and is simultaneously and in the same direction, which can minimize the deformation caused by welding.

[0023] Preferably, the welding method of the welds is rich argon gas shielded welding using solid wire ER69-G, Φ=1.2, the volume ratio of Ar to CO2 in the rich argon gas being 4:1, the welding current being 240-260 A, the welding voltage being 30-32 V, and the welding speed being 250-300 mm / min.

[0024] Preferably, the pre-deformation comprises transverse deformation and longitudinal deformation, the transverse deformation having a sag amount of 140-150 mm, and the longitudinal deformation having a sag amount of 30-40 mm.

[0025] Preferably, the cold straightening is performed using a plate unit cold straightening machine, and the straightening amount is 5-6 mm.

[0026] Preferably, the plate unit cold straightening machine comprises a fixing unit and a straightening unit, the fixing unit comprises a straightening rack on which the bridge deck slab can be placed, and the straightening unit comprises upper and lower rollers fixed on the straightening rack and installed on the upper and lower sides of the bridge deck slab, respectively.

[0027] Preferably, the specific step of the cold straightening is that the bridge deck is placed between the upper and lower rollers, the bridge deck is pulled by external force to pass through the middle of the upper and lower rollers, and the extrusion straightening is completed.

[0028] Preferably, the temperature of the fire straightening is 660-700℃.

[0029] The beneficial effect of the preferred scheme is that, during the cold straightening, the local deformation of the larger part cannot be straightened in place at one time, and the local secondary correction needs to be combined with the fire straightening to ensure the quality of the straightening, and the temperature of the fire straightening does not affect the performance of the 500MPa grade stainless steel composite steel plate.

[0030] Through the above technical scheme, the following beneficial effects are achieved:

[0031] The present application solves the problem of straightening difficulty of the 500MPa grade stainless steel composite plate U rib plate unit in the preparation process through pre-deformation, welding, cold straightening and fire straightening, and realizes the high-precision manufacturing of the 500MPa grade stainless steel composite steel plate U rib plate unit. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a schematic diagram of the U rib assembly position line of the bridge deck in examples 1-3;

[0033] Figure 2 is a schematic diagram of the reverse deformation jig in examples 1-3;

[0034] Figure 3 is a schematic diagram of the straightening unit of the plate unit cold straightening machine in examples 1-3;

[0035] Figure 4 is a schematic diagram of the finished product of the 500MPa grade stainless steel composite plate U rib plate unit in examples 1-3; DETAILED DESCRIPTION

[0036] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0037] Example 1:

[0038] The preparation method of the 500MPa grade stainless steel composite steel plate U rib plate unit comprises the following steps:

[0039] (1) Select the 500MPa grade stainless steel composite steel plate with 19.5mm Q500qE steel plate as the base layer and 2.5mm S31603 stainless steel plate as the stainless steel layer as the bridge deck.

[0040] (2) Cut and fabricate U-ribs with dimensions of 8mm×719mm×12000mm; cut the bridge deck with dimensions of (19.5+2.5)mm×3630mm×12030mm; use a laser scribing machine to scribing 6 sets of U-rib assembly position lines on the bridge deck, such as Figure 1 As shown, the U-rib assembly position lines are numbered from left to right as groups 1, 2, 3, 4, 5, and 6, with a group spacing of 250mm. A U-rib tack welding machine is used to complete the assembly and tack welding of the U-ribs and the bridge deck. Six U-ribs are installed on the six U-rib assembly position lines. Solid welding wire ER69-G (Φ1.0) is used for CO2 gas shielded welding, with a welding current of 200A, a welding voltage of 26V, a welding speed of 550mm / min, a single tack weld length of 40mm, and a spacing of 200mm between weld points, resulting in the assembled U-rib plate unit.

[0041] (3) Place the assembled U-rib plate unit in such a position as Figure 2 The bidirectional reverse deformation is performed on the reverse deformation frame shown (publication number CN115041909A), with the lateral sag set to 150mm and the longitudinal sag set to 40mm, to obtain the deformed U-rib plate element.

[0042] (4) Weld the bevel of the U-rib on the deformed U-rib plate unit. Welding is carried out simultaneously and in the same direction according to the order of the U-rib assembly position lines of groups 3 and 5, groups 2 and 4, and groups 1 and 6. The weld is carried out using solid welding wire ER69-G (Φ1.2) for argon-rich gas shielded welding. The volume ratio of Ar to CO2 in the argon-rich gas is 4:1. The welding current is 260A, the welding voltage is 30V, and the welding speed is 300mm / min to obtain the welded U-rib plate unit.

[0043] (5) The welded U-rib plate unit is cold-straightened using a plate unit cold straightening machine, wherein the straightening unit of the cold straightening machine is as follows: Figure 3 As shown, the correction amount is set to 6mm; then the uneven parts are straightened by fire, and the fire straightening temperature is set to 660℃ to obtain the straightened U-rib plate unit.

[0044] (6) Trim the four sides of the orthopedic U-rib plate unit to obtain Figure 4 The U-rib plate unit shown is made of 500MPa grade stainless steel composite steel plate.

[0045] Example 2:

[0046] The preparation method of 500MPa grade stainless steel composite steel plate U-rib plate unit includes the following steps:

[0047] (1) A 500MPa grade stainless steel composite steel plate with 20mm Q500qE steel plate as base layer and 3mm S31603 stainless steel plate as stainless steel layer is selected as bridge deck.

[0048] (2) Cut the U-rib, the specification is 8mm x 719mm x 12000mm; cut the bridge deck plate, the specification after cutting is (20+3)mm x 3630mm x 12030mm; use a laser marking machine to draw 6 groups of U-rib assembly position lines on the bridge deck plate, as shown in Figure 1 , numbered as the 1st, 2nd, 3rd, 4th, 5th, and 6th groups of U-rib assembly position lines from left to right, with an interval of 300mm between groups; use a U-rib positioning and welding machine to complete the assembly and positioning welding of the U-rib and the bridge deck plate, install 6 U-ribs on the 6 groups of U-rib position lines, and use solid welding wire ER69-G (Φ1.0) for CO2 gas shielded welding, with a welding current of 220A, a welding voltage of 28V, a welding speed of 600mm / min, a single positioning welding length of 80mm, and an interval of 400mm between welding points, to obtain an assembled U-rib plate unit.

[0049] (3) Place the assembled U-rib plate unit on the reverse deformation jig (publication number CN115041909A) shown in Figure 2 for bidirectional reverse deformation, with a transverse height setting of 140mm and a longitudinal height setting of 30mm, to obtain a deformed U-rib plate unit.

[0050] (4) Weld the groove of the U-rib on the deformed U-rib plate unit, and weld according to the order of the 3rd and 5th groups, the 2nd and 4th groups, and the 1st and 6th groups of U-rib assembly position lines simultaneously in the same direction, and use solid welding wire ER69-G (Φ1.2) for argon-rich gas shielded welding, with a volume ratio of Ar to CO2 in the argon-rich gas being 4:1, a welding current of 240A, a welding voltage of 32V, and a welding speed of 300mm / min, to obtain a welded U-rib plate unit.

[0051] (5) Use a plate unit cold straightening machine to cold straighten the welded U-rib plate unit, with a straightening unit of the cold straightening machine as shown in Figure 3 , and set the straightening amount to 5mm; then fire straighten the local uneven parts at a temperature of 680℃, to obtain a straightened U-rib plate unit.

[0052] (6) Edge the four sides of the straightened U-rib plate unit, to obtain a 500MPa grade stainless steel composite steel plate U-rib plate unit as shown in Figure 4 .

[0053] Example 3:

[0054] A method for preparing a 500MPa grade stainless steel composite steel plate U-rib plate unit, comprising the following steps:

[0055] (1) Select a 500MPa grade stainless steel composite steel plate with a 20.5mm Q500qE steel plate as the base layer and a 3.5mm S31603 stainless steel plate as the stainless steel layer as the bridge deck plate.

[0056] (2) Cut and fabricate U-ribs with dimensions of 8mm×719mm×12000mm; cut the bridge deck with dimensions of (20.5+3.5)mm×3630mm×12030mm; use a laser scribing machine to scribing 6 sets of U-rib assembly position lines on the bridge deck, such as Figure 1 As shown, the U-rib assembly position lines are numbered from left to right as groups 1, 2, 3, 4, 5, and 6, with a group spacing of 275mm. A U-rib tack welding machine is used to complete the assembly and tack welding of the U-ribs and the bridge deck. Six U-ribs are installed on the six U-rib assembly position lines. Solid welding wire ER69-G (Φ1.0) is used for CO2 gas shielded welding, with a welding current of 210A, a welding voltage of 27V, a welding speed of 575mm / min, a single tack weld length of 60mm, and a spacing of 300mm between weld points, resulting in the assembled U-rib plate unit.

[0057] (3) Place the assembled U-rib plate unit in such a position as Figure 2 The bidirectional reverse deformation is performed on the reverse deformation frame shown (publication number CN115041909A), with the lateral sag set to 145mm and the longitudinal sag set to 35mm, to obtain the deformed U-rib plate element.

[0058] (4) Weld the bevel of the U-rib on the deformed U-rib plate unit. Welding is carried out simultaneously and in the same direction according to the order of the U-rib assembly position lines of groups 3 and 5, groups 2 and 4, and groups 1 and 6. The weld is carried out using solid welding wire ER69-G (Φ1.2) for argon-rich gas shielded welding. The volume ratio of Ar to CO2 in the argon-rich gas is 4:1. The welding current is 250A, the welding voltage is 31V, and the welding speed is 275mm / min to obtain the welded U-rib plate unit.

[0059] (5) The welded U-rib plate unit is cold-straightened using a plate unit cold straightening machine, wherein the straightening unit of the cold straightening machine is as follows: Figure 3 As shown, the correction amount is set to 5.5mm; then, the uneven parts are straightened by fire, and the fire straightening temperature is set to 700℃ to obtain the straightened U-rib plate unit.

[0060] (6) Trim the four sides of the orthopedic U-rib plate unit to obtain Figure 4 The U-rib plate unit shown is made of 500MPa grade stainless steel composite steel plate.

[0061] Comparative Example 1:

[0062] Other conditions are the same as in Example 3, except that the heat treatment temperature is set to 750°C.

[0063] Comparative Example 2:

[0064] Other conditions are the same as example 3, except that the fire straightening temperature is set to 650℃.

[0065] Table 1 Performance parameters of 500MPa grade stainless steel composite steel plate U-rib plate unit obtained in examples and comparative examples

[0066]

[0067] The 500MPa grade stainless steel composite steel plate U-rib plate units obtained in example 3, comparative example 1 and comparative example 2 are tested for performance, and the results are shown in Table 1. As shown in the table, the fire straightening temperature used in comparative example 1 is 750℃, which is a commonly used fire straightening temperature. After fire straightening at this temperature, the mechanical properties of the stainless steel composite steel plate are all lower than the standard reference values, and even delamination may occur, which is very unfavorable for the use of the steel plate. In comparative example 2, 650℃ is used for fire straightening, although the mechanical properties reach the standard values, but because the temperature is too low, the effect of fire straightening deformation is poor, and it is difficult to achieve the desired effect, therefore 700℃ in example 3 is finally selected as the highest fire straightening temperature. In actual operation, there may be local temperature differences, therefore a certain temperature range is selected, and 660-700℃ is selected as the best fire straightening temperature.

[0068] The present application has the following advantages:

[0069] By combining various methods such as pre-deformation, simultaneous symmetrical weld welding, cold straightening and auxiliary fire straightening, the dilemma of poor low-temperature straightening effect and poor high-temperature straightening steel performance of the U-rib plate unit of the high-strength stainless steel composite plate bridge deck is solved under the premise of ensuring that the mechanical properties of the composite steel plate meet the standard, and the high-precision manufacturing of the 500MPa grade stainless steel composite steel plate U-rib plate unit is realized.

[0070] The preferred embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the specific details in the above-described embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0071] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

[0072] In addition, various different embodiments of the present application can also be combined in any manner, as long as they do not deviate from the idea of the present application, and they should also be considered as disclosed by the present application.

Claims

1. A method of manufacturing a 500 MPa grade stainless steel composite steel plate U-rib plate unit, characterized by, Includes the following steps: (1) 500MPa grade stainless steel composite steel plate is selected as bridge deck; the 500MPa grade stainless steel composite steel plate is composed of a base layer and a stainless steel layer, the base layer is Q500qE steel plate, and the stainless steel layer is S31603 stainless steel plate. (2) Position and weld the U-rib onto the bridge deck to obtain the assembled U-rib plate unit; (3) The assembled U-rib plate unit is pre-deformed to obtain a deformed U-rib plate unit; (4) Welding is performed between the U-rib and the bridge deck on the deformed U-rib plate unit to obtain a welded U-rib plate unit; (5) The welded U-rib plate unit is cold straightened, and then fire straightening is used to assist in the straightening to obtain the straightened U-rib plate unit; (6) Trim the edges of the straightened U-rib plate unit to obtain the 500MPa grade stainless steel composite steel plate U-rib plate unit; The positioning welding includes the following steps: drawing 6 sets of U-rib assembly position lines with a group spacing of 250~300mm on the bridge deck, numbering the U-rib assembly position lines from left to right as the 1st, 2nd, 3rd, 4th, 5th and 6th U-rib assembly position lines, and welding the U-ribs on the U-rib assembly position lines. The welds are welded simultaneously and in the same direction according to the order of the U-rib assembly position lines of groups 3 and 5, groups 2 and 4, and groups 1 and 6. The pre-deformation includes lateral deformation and longitudinal deformation, wherein the lateral deformation sag is 140~150mm and the longitudinal deformation sag is 30~40mm; The cold straightening is performed using a plate unit cold straightening machine, with a straightening amount of 5~6mm; the heat straightening temperature is 660~700℃; The plate unit cold straightening machine includes a fixing unit and a straightening unit. The fixing unit includes a straightening frame for placing the bridge panel. The straightening unit includes an upper roller and a lower roller, which are fixed on the straightening frame and installed on the upper and lower sides of the bridge panel, respectively. The specific steps of the cold straightening are as follows: the bridge panel is placed between the upper and lower rollers, and the bridge panel is pulled by external force to pass through the middle of the upper and lower rollers to complete the compression straightening.

2. The method for preparing a 500MPa grade stainless steel composite plate U-rib unit according to claim 1, characterized in that, The chemical composition of the base layer is as follows (by mass percentage): C≤0.11%, Si≤0.55%, Mn:1.0~1.7%, P≤0.02%, S≤0.01%, Cr≤0.8%, Ni≤0.7%, Mo≤0.3%, with the balance being Fe and unavoidable impurities; the chemical composition of the stainless steel layer is as follows (by mass percentage): C≤0.03%, Si≤0.75%, Mn≤2%, P≤0.045%, Cr:16~18%, Ni:10~14%, Mo:2~3%, with the balance being Fe and unavoidable impurities; the thickness of the Q500qE steel plate is 19.5~20.5mm, and the thickness of the S31603 stainless steel plate is 2.5~3.5mm.

3. The method for preparing a 500MPa grade stainless steel composite plate U-rib unit according to claim 2, characterized in that, The welding method of the positioning welding is CO2 gas shielded welding using solid wire ER69-G, Φ=1.0, welding current is 200-220 A, welding voltage is 26-28 V, welding speed is 550-600 mm / min, single positioning welding length is 40-80 mm, and the interval between welding points is 200-400 mm.

4. The method for preparing a 500MPa grade stainless steel composite steel plate U-rib unit according to claim 3, characterized in that, The welding method of the welding seam is argon-rich gas shielded welding using solid wire ER69-G, Φ=1.2, the volume ratio of Ar to CO2 in the argon-rich gas is 4:1, the welding current is 240-260 A, the welding voltage is 30-32 V, and the welding speed is 250-300 mm / min.

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