Production method of cold-rolled titanium steel composite plate coil

Abstract

The invention provides a production method of a cold-rolled titanium steel composite plate coil. Industrial production is achieved through the following steps that S1, the titanium steel composite plate coil is selected as a cold-rolled raw material; s2, removing the titanium layer at the head and the tail of the raw material to expose the steel base material, and welding the steel base material with the stainless steel leading tape; s3, a continuous annealing furnace is adopted for annealing the composite plate coil welded in the step S2, shot blasting is carried out after annealing, and acid pickling is carried out after shot blasting; a reversible reciprocating rolling mill is adopted for rolling, a constant rolling force mode is adopted for cold rolling, the accumulative deformation is controlled to be 50%-75%, and the single pass is smaller than or equal to 15%; s5, degreasing the cold-rolled composite plate coil; s6, carrying out multi-step vacuum annealing on the degreased composite plate coil; s7, flattening the composite plate roll subjected to vacuum annealing; and S8, the flattened composite plate coil is pulled and straightened, and the cold-rolled titanium steel composite plate coil is prepared. According to the method, the continuous production of the cold-rolled titanium steel composite plate coil with good performance can be realized by adopting a conventional production line without first-pass heavy reduction or a special powerful rolling mill.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of titanium steel composite plate manufacturing, in particular, especially relates to a production method of cold-rolled titanium steel composite plate coil. BACKGROUND

[0002] Titanium steel composite plate gradually replaces part of the application of hot-rolled pure titanium plate coil in many fields due to its excellent performance and significant cost advantage of titanium and steel. With the continuous progress of manufacturing technology, more and more application fields put forward the demand for cold-rolled titanium steel composite plate, expecting it to replace pure titanium cold-rolled plate. However, as of now, there is no relevant report on cold-rolled titanium steel composite plate.

[0003] The traditional bimetal cold-rolled composite process is a three-step production process of "surface treatment + cold-rolled composite + diffusion annealing", that is, two kinds of to-be-combined metals or alloys which have been subjected to surface treatment are directly put into a rolling mill for low-temperature or room-temperature rolling, and then put into a heating furnace for diffusion annealing, so as to produce a rolled bimetal composite plate material with a desired thickness. There is a critical deformation amount in the first pass of rolling, and below this critical deformation amount, effective combination cannot be achieved, so in actual production, it is generally required to reach 60% to 70%, or even higher, so the requirements for the rolling mill are higher. At present, this method is mainly applied in aluminum-based multilayer metal composite, and copper-aluminum, steel-aluminum, nickel-iron alloy-aluminum bimetal composite plates have been produced, but it is not suitable for titanium steel composite plate.

[0004] Previously, some scholars have conducted relevant research on cold-rolled titanium steel composite plate and proposed a "cold-heat rolling composite method" to prepare titanium steel composite plate, that is, titanium / steel group blanks are pre-combined through cold rolling to avoid oxidation of the titanium / steel interface during subsequent hot rolling, and then the interface bonding quality is improved by using induction heating and single-pass hot rolling, so as to prepare titanium / steel composite plate. The thicknesses of the raw materials used are TA2 0.2mm and Q235 steel 4.4mm, which are first cold-rolled to 2.5mm, and then hot-rolled to a finished thickness of 1.2mm. This method actually belongs to the hot rolling method, and the cold rolling process in the above process is equivalent to the vacuum group material link of hot rolling. The titanium steel composite plate produced by this method has a limited width, and only narrow strips below 300mm can be trial-produced, and stable production cannot be achieved. SUMMARY

[0005] In view of the technical blank of industrialized production of cold-rolled titanium steel composite plate coil, the present application provides a production method of cold-rolled titanium steel composite plate coil.

[0006] The technical means adopted by the present application are as follows: A production method of cold-rolled titanium steel composite plate coil, comprising the following steps: S1, raw material preparation: titanium steel composite plate roll is selected as the cold rolling raw material. Previously, titanium steel composite plate has only been used as a terminal product and has never been used as a cold rolling raw material.

[0007] S2, lead welding: remove the titanium layer at the head and tail of the raw material to expose the steel base material, and weld the steel base material and the stainless steel lead; S3, annealing, shot blasting and pickling: use a continuous annealing furnace to anneal the composite plate roll after welding in S2, then perform shot blasting after annealing, and then perform pickling after shot blasting; S4, cold rolling: reversible reciprocating mill is used for rolling, and constant rolling force mode is used for rolling; S5, degreasing of the cold-rolled composite plate roll; S6, multi-step vacuum annealing of the degreased composite plate roll; S7, leveling of the vacuum annealed composite plate roll; S8, tension leveling of the leveled composite plate roll to prepare a cold-rolled titanium steel composite plate roll.

[0008] Further, in S1, the titanium steel composite plate roll prepared by direct rolling is preferably used as the raw material (better interface bonding quality and consistency).

[0009] Further, in S2, the titanium layer within a range of 300 mm at the head and tail of the titanium steel composite plate roll raw material is removed; and the welding parameters are determined according to the specific grades of the steel base material and the steel lead.

[0010] Further, in S3, the annealing temperature is 650-750℃.

[0011] Further, in S3, HF and HNO3 mixed acid is used for pickling, wherein the concentration of HF is 10-20g / L, the concentration of HNO3 is 100-170g / L, and the ratio of HNO3 to HF is ≥10; the acid temperature is controlled between 35-45℃, the rinsing water temperature is controlled within a range of 50-70℃, and the pickling is immediately followed by drying.

[0012] Further, in S4, when a single plate is rolled, a tension device is added to realize tension rolling during reversible reciprocating mill rolling.

[0013] Further, in S4, the rolling tension is set according to the same specification of cold-rolled titanium roll, the single pass deformation is not more than 15%, and the cumulative deformation is controlled within a range of 50%-75%; when the total deformation exceeds 70%, an intermediate annealing is added before continuing rolling, at which time S3 and S4 are repeated; when edge cracking or edge partial layering occurs during rolling, the edge is cut to remove the defect part before continuing rolling.

[0014] Further, in S5, the coiling tension is reduced by 10% based on the same specification of cold-rolled titanium roll.

[0015] Furthermore, in the step S6, the vacuum degree of the multi-step vacuum annealing is ≤4×10 -2 Pa; the temperature of the first step vacuum annealing is 200°C, the heating rate is 60-100°C / h, and the holding time is 360-600min; the temperature of the second step vacuum annealing is 450°C, the heating rate is 60-100°C / h, and the holding time is 480-840min; the heating rate of the third step vacuum annealing is 10-50°C / h, the temperature is determined by the steel substrate process, and does not exceed 850°C.

[0016] Furthermore, in S7, the temper rolling force is performed according to the cold-rolled titanium coil with the same specifications.

[0017] Furthermore, in S8, the tensile elongation is controlled within a range of 0.2% to 1.2%.

[0018] Compared with the prior art, the present invention has the following advantages: 1. The production method of the cold-rolled titanium-steel composite coil provided by the present invention does not require a large first-pass reduction, nor does it require a special high-power rolling mill. Cold-rolled titanium-steel composite coils with good performance can be produced using conventional production lines.

[0019] 2. The production method of cold-rolled titanium-steel composite plate coils provided by the present invention breaks through the bottleneck of industrialized production of cold-rolled titanium-steel composite plates and can realize continuous production of wide-width cold-rolled titanium-steel composite plate coils.

[0020] 3. The production method of cold-rolled titanium steel composite plate coil provided by the present invention has strong process compatibility, does not require a special strong rolling mill, and adopts a conventional reversible rolling mill, avoiding the deformation requirement of the first large pressing in the traditional process.

[0021] 4. The production method of the cold-rolled titanium-steel composite coil provided by the present invention uses titanium-steel composite coil as raw material, which is different from the traditional method (usually using cold-rolled titanium and cold-rolled steel plates as raw materials) and has lower raw material costs.

[0022] 5. The production method of the cold-rolled titanium-steel composite coil provided by the present invention has stable product quality, good interface bonding consistency, and the finished product has good forming performance.

[0023] Based on the above reasons, the present invention can be widely promoted in the fields of titanium steel composite plate manufacturing and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0025] Figure 1 Flowchart for the method of the present application. DETAILED DESCRIPTION

[0026] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0027] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. The description of the at least one exemplary embodiment is actually only illustrative in nature and is in no way intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0028] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a presence of the features, steps, operations, devices, components and / or combinations thereof.

[0029] Unless specifically stated otherwise, the relative arrangements of the components and steps illustrated in these embodiments and the numerical expressions and values set forth herein are not limiting of the scope of the present application. It should be understood that the various parts of the drawings are not necessarily drawn to scale, and that, for the purpose of convenience and clarity, not all components can be shown in a given figure. Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but rather can be assumed to be known by those of ordinary skill in the art. In all examples shown and discussed herein, any specific values should be interpreted as merely illustrative of the examples, and not as a limitation thereon. Thus, other examples of the exemplary embodiments can have different values. It is noted that like references and labels can be used to denote like items throughout the drawings, and thus once an item is defined in one drawing, it is not necessary to further discuss it in the remaining drawings.

[0030] The present invention provides a production method for cold-rolled titanium-steel composite plate coils, which is an industrial production method. Different from the traditional cold-rolled composite plate production process, it does not require a large first-pass reduction and does not require a special high-power rolling mill. Cold-rolled titanium-steel composite plate coils with good performance can be prepared using conventional production lines, thereby realizing continuous production of cold-rolled titanium-steel composite plate coils with good performance.

[0031] like Figure 1 As shown, the process scheme for producing cold-rolled titanium-steel composite coils of the present invention is as follows: titanium-steel composite coil raw material → leader welding → annealing, shot blasting, and pickling → cold rolling → (annealing, shot blasting, and pickling → cold rolling) → degreasing → vacuum annealing → flattening → straightening → packaging. This invention uses titanium-steel composite coils as the raw material for cold rolling and performs cold rolling according to conventional processes. The finished product specifications can cover the common specifications of existing pure titanium coils. The following process flow details the technology and implementation methods of the present invention, which can be industrialized through the following steps: S1. Raw material preparation Hot-rolled titanium-steel composite coils produced by rolling are preferred as the raw material for cold rolling. Compared to titanium-steel composite coils produced by explosion-molding methods, which exhibit a corrugated interface with microcracks and micropores, those produced by rolling methods have a denser and smoother interface, which facilitates interface regulation and thickness control in subsequent processes.

[0032] S2. Lead welding Since titanium and steel cannot be welded, the titanium layer in the composite plate raw material needs to be removed when welding the stainless steel guide to expose the steel substrate. Steel-steel connection is adopted, and the welding parameters are determined by the specific grades of the steel substrate and the steel guide.

[0033] S3, annealing, shot blasting and pickling The annealing temperature is 650-750℃. The main purpose of annealing at this stage is to relieve stress. Too low a temperature is not conducive to stress removal, while too high a temperature will cause excessive TiC growth at the interface, deteriorating the bonding performance.

[0034] During shot blasting, the actual shot blasting force on the upper and lower surfaces must be consistent, and the actual flatness of the board surface after shot blasting is used as the standard.

[0035] For pickling, use a mixture of HF and HNO3, with an HF concentration of 10-20 g / L and an HNO3 concentration of 100-170 g / L. The ratio of HNO3 to HF should be ≥ 10. The acid temperature should be controlled between 35-45°C. The rinse water temperature should be controlled between 50-70°C. Dry immediately after pickling.

[0036] S4, cold rolling The steel is rolled using a reversible reciprocating rolling mill and a constant rolling force mode (the constant rolling force mode is a control method during rolling).

[0037] Reversible rolling mill is adopted. If single plate is rolled, then a tension device is needed to realize tension rolling. Otherwise, serious warping phenomenon will occur, which will make the rolling process difficult to continue.

[0038] Constant rolling force mode is adopted. The existing thickness gauge of the rolling line cannot detect the thickness of the dissimilar bimetal, so the AGC (automatic thickness control system) is not put into use during the rolling process, and manual thickness measurement is carried out after each pass rolling.

[0039] The rolling tension is set according to the same specification of cold-rolled titanium coil.

[0040] The single-pass deformation should not exceed 15%, and the cumulative deformation should be controlled within 50%-75%. If it is less than 50%, the interfacial compound, especially the large TiC, cannot be completely broken and dispersed, which is not conducive to the bonding performance; and if it exceeds 75%, the interface will be damaged, resulting in titanium steel delamination.

[0041] When the total deformation exceeds 70%, an intermediate annealing pass is needed to continue rolling, at which time steps S3 and S4 can be repeated.

[0042] If edge cracking or edge delamination occurs during rolling, edge cutting is needed to remove the defect part before continuing rolling, otherwise it will lead to strip breakage and the delamination area will also increase with the increase of reduction.

[0043] S5, degreasing The coiling tension is reduced by 10% based on the same specification of cold-rolled titanium coil.

[0044] S6, vacuum annealing Multi-step vacuum annealing is adopted, and the vacuum degree is ≤4×10 -2 Pa. The first step is 200℃, the heating rate is 60-100℃ / h, and the holding time is 360-600min; the second step is 450℃, the heating rate is 60-100℃ / h, and the holding time is 480-840min; the third step is 10-50℃ / h, and the specific temperature is determined by the steel base material process, but it cannot exceed 850℃, otherwise it will lead to the decrease of interfacial bonding performance.

[0045] S7, skin pass The skin pass rolling force is executed according to the same specification of cold-rolled titanium coil.

[0046] S8, tension leveling The tension leveling elongation is controlled within 0.2%-1.2%, which is determined according to the specific plate shape.

[0047] The present application is suitable for producing titanium steel composite plate by direct rolling method, and can be popularized in steel enterprises, and high bonding strength products can be prepared, which has good popularization and application prospect.

[0048] The average economic benefit of the cold-rolled titanium steel composite plate production method can reach 0.5 ten thousand yuan / ton.

[0049] Embodiment 1 The cold-rolled 0.1mm TA1+0.4mm St12 composite plate produced by the production method of the application specifically comprises the following steps: S1, using 1mm TA1+4mm St12 hot-rolled titanium steel composite coil produced by rolling method as the cold-rolled raw material.

[0050] S2, removing the titanium layer within the range of 300mm at the head and tail of the hot-rolled titanium steel composite coil to expose the base material St12. Welding the head and tail base material St12 with the stainless steel leading tape together.

[0051] S3, annealing by using continuous annealing furnace, and the annealing temperature is 730℃. After annealing, shot blasting is performed. After shot blasting, pickling is performed, and the pickling adopts 110g / L HNO3 and 10g / L HF pickling, and the acid temperature is controlled at 40-45℃. The rinsing water temperature is 70℃. After pickling, drying is immediately performed, and no water stains are left on the plate surface.

[0052] S4, cold rolling is performed by using six-roll single-stand rolling mill. Since the total thickness of the raw material is 5mm, the finished product thickness is 0.5mm, and the total deformation amount is 90%, which exceeds the maximum cumulative deformation requirement, therefore the cold rolling is divided into two rolling processes. The first rolling process is from 5.0mm to 1.5mm, and the cumulative deformation amount is 70%, and the single pass deformation amount is controlled at about 10%. After rolling to 1.5mm, S3 is repeated. The second rolling process is from 1.5mm to the finished product thickness of 0.5mm, and the cumulative deformation amount is 67%, and the single pass deformation amount is about 10%, and the last pass is about 5%. Constant rolling force mode is adopted for rolling, and the maximum rolling force does not exceed 700t.

[0053] S5, degreasing is performed by using NaOH solution, and the tension during degreasing of the 0.5mm cold-rolled titanium coil is 1600DaN, therefore the coiling tension of the composite coil is 1440DaN. After degreasing, drying is immediately performed, and no water stains are left on the surface.

[0054] S6, multi-step vacuum annealing is adopted, and the actual vacuum degree is 2.1×10 -2 Pa. The heating rate of the first step vacuum annealing is 100℃ / h, 200℃ is kept for 480min; the heating rate of the second step vacuum annealing is 100℃ / h, 450℃ is kept for 720min; the heating rate of the third step vacuum annealing is 10℃ / h, 550℃ is kept for 900min.

[0055] S7, the flat rolling force is set to 150t according to the 0.5mm TA1 process.

[0056] S8, the stretch straightening rate is 0.5%, and the plate shape is flat.

[0057] Through the above steps, the finished product 0.5mm TA1 / St12 cold-rolled composite roll is successfully obtained, the product surface quality is equivalent to the same material, the shape is good, the forming performance is good, and the user punching test is qualified, and the interface is not delaminated.

[0058] Example 2 The 0.5mm TA1+1.5mm St12 composite plate produced by the production method of the application specifically comprises the following steps: S1, using 1mm TA1+3mm St12 hot-rolled titanium steel composite roll produced by rolling method as cold-rolled raw material.

[0059] S2, the titanium layer within 300mm range of the head and tail of the hot-rolled titanium steel composite roll is removed to expose the base material Q235. The head and tail base material Q235 is welded with the stainless steel leading tape.

[0060] S3, annealing is carried out by using continuous annealing furnace, and the annealing temperature is 750℃. After annealing, shot blasting is carried out. After shot blasting, pickling is carried out, and the pickling adopts 150g / L HNO3 and 12g / L HF pickling, and the acid temperature is controlled at 35-40℃. The rinsing water temperature is 70℃. After pickling, drying is carried out immediately, and no water stain is left on the plate surface.

[0061] S4, cold rolling is carried out by using six-roll single-stand rolling mill. Since the total thickness of the raw material is 4mm and the finished product thickness is 2mm, the total deformation is 50%, which does not exceed 75%, so only one rolling pass is needed. The deformation of the first two passes is about 15%, and the rest of the passes is about 10%-12%. The last pass is about 8%. Constant rolling force mode is adopted for rolling, and the maximum rolling force does not exceed 700t.

[0062] S5, NaOH solution is used for degreasing, and the tension of 2.0mm cold-rolled titanium roll during degreasing is 2800DaN, so the coiling tension of the composite roll is 2520DaN. After degreasing, drying is carried out immediately, and no water stain is left on the surface.

[0063] S6, multi-step vacuum annealing is adopted, and the actual vacuum degree is 1.9×10 -2 Pa. The heating rate of the first step vacuum annealing is 60℃ / h, the temperature is kept at 200℃ for 360min; the heating rate of the second step vacuum annealing is 100℃ / h, the temperature is kept at 450℃ for 600min; the heating rate of the third step vacuum annealing is 20℃ / h, the temperature is kept at 650℃ for 7800min.

[0064] S7, the flattening rolling force is set to 220t according to the 2.0mm TA1 process.

[0065] S8, the tension of the straightening is 1.2%, and the shape is flat.

[0066] Through the above steps, the finished product thickness 2.0mm TA1 / St12 cold-rolled composite roll is successfully obtained, the product surface quality is equivalent to the same material, the shape is good, the forming performance is good, the bending forming test, the interface is not layered, and the surface is not cracked.

[0067] Comparative Example 1 The cold-rolled 0.1mm TA1+0.4mm St12 composite plate specifically includes the following steps: S1, using 1mm TA1+4mm St12 hot-rolled titanium steel composite roll produced by rolling method as the cold-rolled raw material.

[0068] S2, the titanium layer within 300mm range of the head and tail of the hot-rolled titanium steel composite roll is removed to expose the base material St12. The head and tail base material St12 is welded together with the stainless steel leading tape.

[0069] S3, annealing is carried out by using continuous annealing furnace, and the annealing temperature is 730℃. After annealing, shot blasting is carried out. After shot blasting, pickling is carried out, and the pickling uses 110g / L HNO3 and 10g / L HF pickling, and the acid temperature is controlled at 40-45℃. The rinsing water temperature is 70℃. After pickling, drying is carried out immediately, and no water stains are left on the plate surface.

[0070] S4, cold rolling is carried out by using six-roll single-stand rolling mill. Since the total thickness of the raw material is 5mm, the finished product thickness is 0.5mm, and the total deformation amount is 90%, which exceeds the maximum cumulative deformation requirement, therefore the cold rolling is divided into two rolling processes. The first rolling process is from 5.0mm to 2.0mm, and the cumulative deformation amount is 60%, and the single pass deformation amount is controlled at about 10%. After rolling to 2.0mm, S3 is repeated. The second rolling process is from 2.0mm to the finished product thickness of 0.5mm, and the cumulative deformation amount is 75%, and the single pass deformation amount is about 18-20%. From the third pass, cracks appear on the edge, and by the fifth pass, the strip is broken due to edge cracking. The broken part is cut off and continues to be rolled, and the single pass deformation amount is adjusted to 10%, but when the thickness is rolled to 0.52mm (at this time the cumulative deformation amount reaches 74%), the interface appears layered.

[0071] Comparative Example 2 (deformation amount less than 50%, failure) The cold-rolled 0.5mm TA1+1.5mm St12 composite plate specifically includes the following steps: S1, using 0.9mm TA1+2.7mm St12 hot-rolled titanium steel composite roll produced by rolling method as the cold-rolled raw material.

[0072] S2, the titanium layer within 300mm range of the head and tail of the hot-rolled titanium steel composite roll is removed to expose the base material Q235. The head and tail base material Q235 is welded together with the stainless steel leading tape.

[0073] S3, annealing in continuous annealing furnace, annealing temperature 750℃. After annealing, shot blasting is carried out. After shot blasting, pickling is carried out, pickling using 150g / L HNO3 and 12g / L HF, acid temperature controlled at 35-40℃. The rinsing water temperature is 70℃. After pickling, drying is carried out immediately, no water stain is left on the plate surface.

[0074] S4, cold rolling using six-roller single-stand rolling mill. Since the total thickness of the raw material is 3.6mm, the finished product thickness is 2mm, and the total deformation is 44%, which does not exceed 75%, only one rolling pass is needed. The single-pass deformation is about 8%-10%. Rolling is carried out using constant rolling force mode, and the maximum rolling force does not exceed 700t.

[0075] S5, using NaOH solution for degreasing, the tension for degreasing of 2.0mm cold-rolled titanium coil is 2800DaN, therefore the coiled tension is 2520DaN. After degreasing, drying is carried out immediately, and no water stain is left on the surface.

[0076] S6, using multi-step vacuum annealing, the actual vacuum degree is 1.9*10 -3 Pa. The first step vacuum annealing has a heating rate of 60℃ / h, 200℃ for 360min; the second step vacuum annealing has a heating rate of 100℃ / h, 450℃ for 600min; the third step vacuum annealing has a heating rate of 20℃ / h, 650℃ for 7800min.

[0077] S7, the flat rolling force is set to 200t according to the 2.0mm TA1 process.

[0078] S8, the straightening elongation is 1.0%, and partial delamination of the titanium-steel composite plate is found during straightening.

[0079] The finished product is subjected to bending test, and delamination occurs at the interface, which cannot be used.

[0080] Comparative Example 3 (annealing temperature is too high, failed) The production method of the present application is used to produce cold-rolled 0.1mm TA1+0.4mm St12 composite plate, which specifically comprises the following steps: S1, using 1mm TA1+4mm St12 hot-rolled titanium-steel composite coil produced by rolling as the cold-rolled raw material.

[0081] S2, the titanium layer within the range of 300mm at the head and tail of the hot-rolled titanium-steel composite coil is removed to expose the base material St12. The head and tail base material St12 is welded together with the stainless steel leading tape.

[0082] S3, annealing in continuous annealing furnace, annealing temperature 730℃. After annealing, shot blasting. After shot blasting, pickling, pickling with 110g / L HNO3 and 10g / L HF, pickling temperature controlled at 40-45℃. Rinsing water temperature 70℃. After pickling, drying immediately, no water stain left on the surface.

[0083] S4, cold rolling with six-roller single stand rolling mill. Since the total thickness of raw material is 5mm, the thickness of finished product is 0.5mm, and the total deformation is 90%, which exceeds the maximum cumulative deformation requirement, so the cold rolling is divided into two rolling processes. The first rolling process is from 5.0mm to 1.5mm, with a cumulative deformation of 70%, and the single pass deformation is controlled at about 10%. After rolling to 1.5mm, repeat S3. The second rolling process is from 1.5mm to the finished product thickness of 0.5mm, with a cumulative deformation of 67%, and the single pass deformation is about 10%, and the last pass is about 5%. Rolling with constant rolling force mode, the maximum rolling force does not exceed 700t.

[0084] S5, degreasing with NaOH solution, the tension during degreasing of 0.5mm cold-rolled titanium coil is 1600DaN, so the coiled tension is 1440DaN. Drying immediately after degreasing, no water stain left on the surface.

[0085] S6, multi-step vacuum annealing, the actual vacuum degree is 2.1x10 -2 Pa. The first step vacuum annealing has a heating rate of 100℃ / h, 200℃ for 480min; the second step vacuum annealing has a heating rate of 100℃ / h, 450℃ for 720min; the third step vacuum annealing has a heating rate of 10℃ / h, 900℃ for 720min.

[0086] S7, the flat rolling force is set to 150t according to the 0.5mm TA1 process.

[0087] S8, the stretch straightening elongation is 0.5%.

[0088] Interface delamination is found in some areas during flatting and stretch straightening, and the sample is taken for bending test, the interface delamination occurs, which cannot be used.

[0089] Comparative Example 4 Cold-rolled 0.5mm TA1 + 1.5mm St12 composite plate S1, 1mm TA1 + 3mm St12 hot-rolled titanium steel composite coil produced by rolling method is selected as the cold-rolled raw material.

[0090] S2, the titanium layer within 300mm range of the head and tail of the hot-rolled titanium steel composite coil is removed to expose the base material Q235. The head and tail Q235 are welded with stainless steel leading tape.

[0091] S3, annealing in a bell furnace, annealing temperature 850℃, holding for 15h. Pickling with 150g / L HNO3 and 12g / L HF, pickling temperature 35-40℃. Rinsing water temperature 70℃. Drying immediately after pickling, no water stain left on the surface of the sheet.

[0092] S4, cold rolling with a six-high single stand rolling mill. Since the total thickness of the raw material is 4mm and the thickness of the finished product is 2mm, the total deformation is 50%, which is less than 75%, so only one rolling pass is needed. The deformation of the first two passes is about 15%, and the deformation of the remaining passes is about 10%-12%. The last pass is about 8%. The rolling is carried out in constant rolling force mode, and the maximum rolling force is not more than 700t.

[0093] S5, degreasing with NaOH solution, the tension during degreasing of 2.0mm cold-rolled titanium coil is 2800DaN, so the coiling tension of the composite coil is 2520DaN. Drying immediately after degreasing, no water stain left on the surface.

[0094] S6, multi-step annealing, the actual vacuum degree is 1.9x10 -2 Pa. The first step, the heating rate is 60℃ / h, holding at 200℃ for 360min; the second step, the heating rate is 100℃ / h, holding at 450℃ for 600min; the third step, the heating rate is 20℃ / h, holding at 650℃ for 7800min.

[0095] S7, the flat rolling force is set to 220t according to the 2.0mm TA1 process.

[0096] S8, the elongation of the straightening is 1.2%, and the sheet shape is flat.

[0097] The finished product cannot be used because the interface delaminates during bending test.

[0098] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing examples, or make equivalent substitutions for part or all of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for producing a cold-rolled titanium steel composite coil, characterized in that: The steps include: S1. Raw material preparation: titanium steel composite plate coil is selected as cold rolling raw material; S2, lead tape welding: remove the titanium layer at the head and tail of the raw material to expose the steel substrate, and weld the steel substrate to the stainless steel lead tape; S3, annealing, shot blasting and pickling: anneal the composite plate coil after welding in S2 in a continuous annealing furnace, and then perform shot blasting and pickling after annealing; S4, cold rolling: using a reversible reciprocating rolling mill and a constant rolling force mode; S5. Degreasing the cold-rolled composite coil; S6. Perform multi-step vacuum annealing on the degreased composite coil; S7, leveling the composite plate coil after vacuum annealing; S8. The flattened composite plate coil is straightened to prepare a cold-rolled titanium steel composite plate coil.

2. The method for producing a cold-rolled titanium-steel composite coil according to claim 1, characterized in that: In S1, the hot-rolled titanium steel composite plate coil produced by the rolling method is used as the raw material.

3. The method for producing a cold-rolled titanium-steel composite coil according to claim 1, characterized in that: In the above-mentioned S2, the titanium layer within 300 mm of the head and tail of the titanium steel composite plate coil raw material is removed; and the welding parameters are determined by the specific grades of the steel substrate and the steel leader.

4. The method for producing a cold-rolled titanium-steel composite coil according to claim 1, characterized in that: In said S3, the annealing temperature is 650-750°C; The pickling adopts HF and HNO3 mixed pickling, wherein the HF concentration is 10-20g / L, the HNO3 concentration is 100-170g / L, and the ratio of HNO3 to HF is ≥10; the acid temperature is controlled between 35-45℃, the rinsing water temperature is controlled within the range of 50-70℃, and drying is carried out immediately after pickling.

5. The method for producing a cold-rolled titanium-steel composite coil according to claim 1, characterized in that: In the above-mentioned S4, when rolling is carried out by a reversible reciprocating rolling mill, when rolling a single plate, a tension device is added to realize tension rolling.

6. The method for producing a cold-rolled titanium-steel composite coil according to claim 1, characterized in that: In S4, the rolling tension is set according to the cold-rolled titanium coil of the same specification, the deformation of a single pass does not exceed 15%, and the cumulative deformation is controlled within 50%-75%. When the total deformation exceeds 70%, an intermediate annealing is added before continuing rolling, and S3 and S4 are repeated at this time. When edge cracking or edge delamination occurs during the rolling process, edge trimming is performed to remove the defective parts before continuing rolling.

7. The method for producing a cold-rolled titanium-steel composite coil according to claim 1, characterized in that: In the S5, the degreasing coiling tension is reduced by 10% based on the cold-rolled titanium coil of the same specification.

8. The method for producing a cold-rolled titanium-steel composite coil according to claim 1, characterized in that: In the above S6, the vacuum degree of the multi-step vacuum annealing is ≤4×10 -2 Pa; the temperature of the first step vacuum annealing is 200°C, the heating rate is 60-100°C / h, and the holding time is 360-600min; the temperature of the second step vacuum annealing is 450°C, the heating rate is 60-100°C / h, and the holding time is 480-840min; the heating rate of the third step vacuum annealing is 10-50°C / h, the temperature is determined by the steel substrate process, and does not exceed 850°C.

9. The method for producing a cold-rolled titanium-steel composite coil according to claim 1, characterized in that: In S7, the temper rolling force is performed according to the cold-rolled titanium coil of the same specification.

10. The method for producing a cold-rolled titanium-steel composite coil according to claim 1, characterized in that: In the above-mentioned S8, the tensile elongation is controlled within a range of 0.2% to 1.2%.

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