A front suspension sway bar, a front suspension sway bar assembly, and a method of manufacture

Abstract

The application relates to a front suspension transverse stabilizer, a front suspension transverse stabilizer assembly and a manufacturing method, which comprises the following steps: cold bending forming and welding of 850MPa hot-rolled high-strength steel to obtain a welded pipe; profiling treatment on the middle part of the welded pipe to form a camber on the welded pipe; and heat treatment of the welded pipe after the profiling treatment to obtain the front suspension transverse stabilizer; the heat treatment comprises the following steps: keeping the temperature at 600-630 DEG C for 20-40 min. Since the welded pipe is a hollow pipe, the weight is far lower than that of a solid steel rod, so a large-diameter welded pipe can be used to replace a small-diameter steel rod, which is beneficial to the light weight of the front suspension transverse stabilizer assembly. Since the welded pipe is used, the cost is lower than that of a seamless steel pipe. According to the actual rigidity requirement, the depth of the camber can be regulated in the profiling treatment, so that the rigidity can be regulated, and the universality of the front suspension transverse stabilizer can be improved. The heat treatment of the welded pipe can eliminate the internal stress of the welded pipe and improve the yield strength and the yield strength ratio of the welded pipe.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transverse stabilizer bar assembly, in particular to a front suspension transverse stabilizer bar, a front suspension transverse stabilizer bar assembly and a manufacturing method. BACKGROUND

[0002] In the field of commercial vehicles, driving comfort is also an index that users pay great attention to. The transverse stabilizer bar assembly in the cab suspension system is an important structure to ensure driving comfort. When the automobile turns, the vehicle body will tilt laterally to a large extent. The role of the front suspension transverse stabilizer bar is to keep the vehicle body balanced as much as possible, reduce the degree of lateral tilt of the vehicle body, and improve the driving comfort. When the automobile runs on a bumpy road, the two sides of the vehicle body will jump up and down. The role of the front suspension transverse stabilizer bar is to buffer the vibration of the vehicle body through elastic deformation, and improve the smoothness.

[0003] The vehicle body stabilizer bar not only needs to withstand torsional fatigue load, but also needs to have a certain ability to resist torsional plastic deformation. Therefore, it is usually made of medium-carbon alloy structural steel or spring steel. The vehicle body stabilizer bar used is mostly a seamless steel pipe or a steel bar. The connection mode of the stabilizer bar with the roll arm is mainly assembly or welding.

[0004] At present, the transverse stabilizer bar assembly structure in the cab suspension system mainly has the following types:

[0005] (1) For example, some related technical solutions adopt a segmented steel bar + connecting block scheme. A plurality of steel bars are used, and the steel bars need to be bent multiple times. A connecting block and a threaded connection are used between the stabilizer bar and the connecting rod. Since the steel bar is solid, the scheme has the problems of large assembly weight and poor lightweight performance. In addition, the rigidity of the structure is fixed, and the rigidity cannot be changed on different vehicle models. Therefore, the structure has a single function and poor universality.

[0006] (2) For example, some related technical solutions adopt an integral steel bar + connecting cylinder scheme. A complete steel bar is used, and the steel bar needs to be bent multiple times to form. The two ends are combined with the connecting cylinder through friction welding. Since the steel bar is solid, the scheme has the problems of large assembly weight and poor lightweight performance. In addition, the rigidity of the structure is fixed, and the rigidity cannot be changed on different vehicle models. Therefore, the structure has a single function and poor universality.

[0007] (3) For example, some related technical solutions adopt a steel bar + precision casting scheme. A complete steel bar is used, and the steel bar needs to be bent multiple times to form. A connecting hole is manufactured at the end of the steel bar by forging process. The roll arm is a precision casting. The stabilizer bar and the roll arm are connected by bolts. Since the steel bar is solid, the scheme has the problems of large assembly weight and poor lightweight performance. In addition, the rigidity of the structure is fixed, and the rigidity cannot be changed on different vehicle models. Therefore, the structure has a single function and poor universality.

[0008] (4) For example, some related technical solutions adopt a seamless steel pipe + precision casting solution, the stabilizing rod adopts a seamless steel pipe, the two ends of the steel pipe are upset, the turnover arm is a precision casting, and the stabilizing rod and the turnover arm are connected in a welding manner. The seamless steel pipe has a relatively high manufacturing cost, and alloy elements need to be added, which further increases the manufacturing cost. In addition, the rigidity of the structure is fixed, and the rigidity cannot be changed on different vehicle models, so the structure has a single function and poor universality. SUMMARY

[0009] Embodiments of the present application provide a front suspension transverse stabilizing rod, a front suspension transverse stabilizing rod assembly and a manufacturing method to solve the problems of large weight and high material and process cost of the transverse stabilizing rod in the related art.

[0010] In a first aspect, a manufacturing method of a front suspension transverse stabilizing rod is provided, which includes the following steps:

[0011] cold bending forming and welding of the 850MPa grade hot-rolled high-strength steel to obtain a welded pipe;

[0012] profile processing of the middle part of the welded pipe to form a camber on the welded pipe;

[0013] heat treatment of the profile-processed welded pipe to obtain a front suspension transverse stabilizing rod;

[0014] The heat treatment includes: holding at a temperature of 600-630℃ for 20-40min.

[0015] In some embodiments, the chemical composition of the 850MPa grade hot-rolled high-strength steel includes, in terms of mass fraction: C≤0.10%, Si≤0.20%, Mn≤1.80%, P≤0.025%, S≤0.015%, Nb≤0.22%, V≤0.22%, Ti≤0.22%, Al≤0.05%, Mo≤0.50%, and the rest is Fe and unavoidable impurity elements.

[0016] The coiling temperature of the 850MPa grade hot-rolled high-strength steel is 550-600℃.

[0017] The yield strength of the 850MPa grade hot-rolled high-strength steel is ≥780MPa, the tensile strength is ≥850MPa, and the elongation A50 is ≥15%.

[0018] The yield strength of the welded pipe is ≥800MPa, the tensile strength is ≥870MPa, and the elongation A is ≥7.5%.

[0019] The welded pipe is obtained by high-frequency induction resistance welding.

[0020] And / or, the welded pipe has one arc surface, and the weld on the welded pipe is located on the opposite side of the arc surface; or, the welded pipe has two arc surfaces, the two arc surfaces are arranged opposite to each other, and the weld on the welded pipe is located between the two arc surfaces.

[0021] In a second aspect, there is provided a front suspension stabilizer bar manufactured by the method for manufacturing a front suspension stabilizer bar as described above.

[0022] In a third aspect, there is provided a method for manufacturing a front suspension stabilizer bar assembly, comprising the following steps:

[0023] The 850MPa-grade hot-rolled high-strength steel is cold-bent and formed, and welded to obtain a welded pipe;

[0024] The middle part of the welded pipe is profiled to form an arc surface on the welded pipe;

[0025] The profiled welded pipe is welded with a turnover arm at both ends;

[0026] The welded pipe is heat treated to obtain a front suspension stabilizer bar assembly;

[0027] The heat treatment comprises: holding at a temperature of 600-630℃ for 20-40min.

[0028] In some embodiments, the manufacturing method further comprises:

[0029] The 510MPa-grade or above girder plate is blanked and stamped to obtain a turnover arm.

[0030] In some embodiments, before the heat treatment of the welded pipe, the manufacturing method further comprises:

[0031] A reinforcing plate is welded at the welding position of the welded pipe and the turnover arm.

[0032] In some embodiments, the manufacturing method further comprises:

[0033] The 510MPa-grade or above girder plate is blanked and stamped to obtain a reinforcing plate.

[0034] In some embodiments, the length L of the arc surface on the welded pipe to the end of the welded pipe and the height H of the reinforcing plate satisfy: L / H≥1.5.

[0035] In some embodiments, the chemical composition of the 850MPa grade hot-rolled high-strength steel includes, in terms of mass fraction: C≤0.10%, Si≤0.20%, Mn≤1.80%, P≤0.025%, S≤0.015%, Nb≤0.22%, V≤0.22%, Ti≤0.22%, Al≤0.05%, Mo≤0.50%, and the balance being Fe and inevitable impurity elements.

[0036] And / or, the coiling temperature of the 850MPa grade hot-rolled high-strength steel is 550-600°C.

[0037] And / or, the yield strength of the 850MPa grade hot-rolled high-strength steel is≥780MPa, the tensile strength is≥850MPa, and the elongation A50 is≥15%.

[0038] And / or, the yield strength of the welded pipe is≥800MPa, the tensile strength is≥870MPa, and the elongation A is≥7.5%.

[0039] And / or, the welded pipe is made by high-frequency induction resistance welding.

[0040] And / or, the welded pipe has one arc surface, and the weld on the welded pipe is located on the opposite side of the arc surface; or the welded pipe has two arc surfaces, the two arc surfaces are arranged opposite to each other, and the weld on the welded pipe is located between the two arc surfaces.

[0041] In a fourth aspect, a front suspension transverse stabilizer assembly is provided, which is manufactured by the manufacturing method of the front suspension transverse stabilizer assembly as described in any of the above.

[0042] The technical scheme provided in the application has the following beneficial effects:

[0043] The manufacturing method of the front suspension transverse stabilizer provided in the embodiments of the application is used to cold-bend and form the 850MPa grade hot-rolled high-strength steel and weld it to make a welded pipe. Since the welded pipe is a hollow pipe rather than a solid rod, the weight of the welded pipe is much lower than that of the solid steel rod, so a large-diameter welded pipe can be used to replace a small-diameter steel rod, which is beneficial to the lightweight of the front suspension transverse stabilizer assembly.

[0044] Since the welded pipe is formed by welding, the cost is lower than that of a seamless steel pipe, and no alloy elements need to be added in the subsequent process of forming the front suspension transverse stabilizer, which further reduces the manufacturing cost.

[0045] The welded pipe undergoes a pressing process to form an arc surface. The purpose of this process is to reduce the stiffness of the middle section, thereby reducing stress concentration at the weld joint between the tilting arm and the welded pipe after subsequent welding. Furthermore, this application allows for adjustment of the depth of the arc surface formed during the pressing process, based on actual stiffness requirements. This easily achieves stiffness adjustment and improves the versatility of the front suspension stabilizer bar.

[0046] Finally, the welded pipe was heat-treated to eliminate internal stress, which further improved the yield strength and yield ratio of the welded pipe. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 A schematic diagram of a welded pipe provided in an embodiment of this application;

[0049] Figure 2 This is a schematic diagram of the welded pipe from another perspective, provided in an embodiment of this application.

[0050] Figure 3 for Figure 2 Diagram of the AA direction;

[0051] Figure 4 for Figure 2 Diagram of the middle BB direction;

[0052] Figure 5 A cross-sectional view of the welded pipe provided in an embodiment of this application;

[0053] Figure 6 A schematic diagram of the front suspension stabilizer bar assembly provided in an embodiment of this application;

[0054] Figure 7 Another perspective view of the front suspension stabilizer bar assembly provided in the embodiments of this application;

[0055] Figure 8 This is a schematic diagram of a flat plate sample provided in an embodiment of this application;

[0056] Figure 9 This is a schematic diagram of a tensile specimen provided in an embodiment of this application.

[0057] In the diagram: 1. Welded pipe; 10. Weld seam; 2. Arc surface; 3. Tilting arm; 4. Reinforcing plate. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] This application provides a method for manufacturing a front suspension stabilizer bar, which can solve the problems of large weight and high material and process costs of stabilizer bars in related technologies.

[0060] See Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown in the figure, this application provides a method for manufacturing a front suspension stabilizer bar, which includes the following steps:

[0061] 101: Cold bending and welding of 850MPa grade hot-rolled high-strength steel to produce welded pipe 1.

[0062] In step 101, the chemical composition of the 850MPa grade hot-rolled high-strength steel, calculated by mass fraction, includes: C≤0.10%, Si≤0.20%, Mn≤1.80%, P≤0.025%, S≤0.015%, Nb≤0.22%, V≤0.22%, Ti≤0.22%, Al≤0.05%, Mo≤0.50%, with the remainder being Fe and unavoidable impurity elements.

[0063] After the above-mentioned 850MPa grade hot-rolled high-strength steel is hot-rolled, the temperature is reduced to 550-600℃ before it can be coiled. That is, the coiling temperature of the 850MPa grade hot-rolled high-strength steel is 550-600℃. The matrix structure of the 850MPa grade hot-rolled high-strength steel is ferrite and carbides.

[0064] The transverse mechanical properties of 850MPa grade hot-rolled high-strength steel meet the following requirements: yield strength ≥780MPa, tensile strength ≥850MPa, and elongation A50 ≥15%.

[0065] 850MPa grade hot-rolled high-strength steel is cold-bent into a tubular shape, and then welded to obtain welded pipe 1. At this time, the mechanical properties of the steel pipe of welded pipe 1 meet the following requirements: yield strength ≥800MPa, tensile strength ≥870MPa, and elongation A ≥7.5%.

[0066] When there are burrs inside or outside the weld 10, deburring can be performed.

[0067] Wherein, there are many ways to weld, such as, as an example, can be used to take high-frequency induction resistance welded pipe 1.

[0068] 102: The middle part of the welded pipe 1 is profiled to form a camber 2 on the welded pipe 1.

[0069] Wherein, before the middle part of the welded pipe 1 is profiled in step 102, the welded pipe 1 can be cut to the required length according to actual needs.

[0070] The middle part of the welded pipe 1 is profiled to form a camber 2 in the middle part of the welded pipe 1, as shown in Figure 4 .

[0071] The depth of the camber 2 can be determined according to actual needs, so that the required camber 2 can be achieved by controlling the stroke of the press head.

[0072] By setting the camber 2, the purpose is to reduce the stiffness of the middle part, and then reduce the stress concentration between the welding part of the flip arm and the welded pipe after the subsequent welding flip arm.

[0073] Wherein, the number of cambers 2 can be determined according to actual needs, such as, as an example, referring to Figure 4 , there is one camber 2 on the welded pipe 1.

[0074] For another example, referring to Figure 5 , there are two cambers 2 on the welded pipe 1, and the two cambers 2 are arranged opposite to each other.

[0075] In addition, in order to prevent the weld 10 from deforming during the profiling process, the weld 10 can be staggered with the camber 2.

[0076] For example, as an example, referring to Figure 4 , when there is one camber 2 on the welded pipe 1, the weld 10 on the welded pipe 1 is located on the opposite side of the camber 2.

[0077] For another example, referring to Figure 5 , when there are two cambers 2 on the welded pipe 1, the two cambers 2 are arranged opposite to each other, and the weld 10 on the welded pipe 1 is located between the two cambers 2.

[0078] After the camber 2 is formed, referring to Figure 4 and Figure 5As shown, an inner fillet with a radius of R1 and an outer fillet with a radius of R2 will appear on the welded pipe 1, in order to prevent the occurrence of wrinkling and folding defects, the inner fillet radius R1 and the outer fillet radius R2 can be controlled, for example, the inner fillet radius R1 and the outer fillet radius R2 should be greater than 1.5 times the wall thickness of the welded pipe 1.

[0079] 103: heat treating the profiled welded pipe 1 to obtain the front suspension transverse stabilizer; wherein the heat treatment comprises: heat preservation at a temperature of 600-630 ℃ for 20-40 min, and then air cooling to room temperature.

[0080] In step 103, the welded pipe 1 is heat treated, which aims to eliminate the internal stress of the welded pipe 1 and improve the hardness of the weld heat-affected zone, so as to improve the yield strength and the yield strength ratio of the welded pipe 1.

[0081] The manufacturing method of the front suspension transverse stabilizer provided by the embodiment of the present application is to cold bend and form 850MPa grade hot-rolled high-strength steel and weld to obtain the welded pipe 1. Since the welded pipe 1 is a hollow pipe and not a solid rod, it is far lower in weight than a solid steel rod, so a large-diameter welded pipe can be used instead of a small-diameter steel rod, which is beneficial to the lightweight of the front suspension transverse stabilizer assembly.

[0082] Since the welded pipe is formed in a welded form, the cost is lower than that of a seamless steel pipe, and no alloy elements need to be added in the subsequent process of forming the front suspension transverse stabilizer, further reducing the manufacturing cost.

[0083] The welded pipe 1 is also profiled to form a camber 2, which aims to reduce the rigidity of the middle part, and then reduce the stress concentration of the welding part between the turnover arm and the welded pipe after the subsequent welding of the turnover arm. In addition, the depth of the camber 2 formed in the profiled process can be adjusted according to the actual rigidity requirement, so that the rigidity adjustment can be easily realized, and the universality of the front suspension transverse stabilizer can be improved.

[0084] Finally, the welded pipe 1 is heat treated, which can further improve the yield strength and the yield strength ratio of the welded pipe 1 by eliminating the internal stress of the welded pipe 1.

[0085] Referring to Figure 1 and Figure 2 As shown, the embodiment of the present application also provides a front suspension transverse stabilizer, which is manufactured by the manufacturing method of the front suspension transverse stabilizer mentioned in the above embodiment.

[0086] Referring to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 6 andFigure 7 As shown, the embodiment of the present application also provides a manufacturing method of the front suspension transverse stabilizer assembly, which comprises the following steps:

[0087] 201: cold bending forming of the 850MPa grade hot-rolled high-strength steel and welding to obtain a welded pipe 1.

[0088] In step 201, the chemical composition of the 850MPa grade hot-rolled high-strength steel includes, in terms of mass fraction: C≤0.10%, Si≤0.20%, Mn≤1.80%, P≤0.025%, S≤0.015%, Nb≤0.22%, V≤0.22%, Ti≤0.22%, Al≤0.05%, Mo≤0.50%, and the rest is Fe and inevitable impurity elements.

[0089] After the 850MPa grade hot-rolled high-strength steel is formed by hot rolling, the temperature is reduced to 550-600°C, and then coiling can be performed, that is, the coiling temperature of the 850MPa grade hot-rolled high-strength steel is 550-600°C, and the base structure of the 850MPa grade hot-rolled high-strength steel is ferrite and carbide.

[0090] The transverse mechanical properties of the 850MPa grade hot-rolled high-strength steel meet: yield strength≥780MPa, tensile strength≥850MPa, and elongation A50≥15%.

[0091] The 850MPa grade hot-rolled high-strength steel is cold bending formed into a tubular shape, and then welded to obtain a welded pipe 1, at this time the mechanical properties of the steel pipe of the welded pipe 1 meet: yield strength≥800MPa, tensile strength≥870MPa, and elongation A≥7.5%.

[0092] When there are burrs and the like inside and outside the weld 10, burr scraping treatment can be performed.

[0093] There are many welding methods, for example, as an example, high-frequency induction resistance welding can be used to obtain the welded pipe 1, see Figure 3 As shown, where r is the inner radius and R0 is the outer radius.

[0094] 202: profiling treatment is performed on the middle part of the welded pipe 1 to form a camber surface 2 on the welded pipe 1.

[0095] In step 202, before the profiling treatment is performed on the middle part of the welded pipe 1, the welded pipe 1 can be cut to the desired length according to actual needs.

[0096] The profiling treatment is performed on the middle part of the welded pipe 1 to form a camber surface 2 in the middle part of the welded pipe 1, as shown in Figure 4 .

[0097] The depth of the arc surface 2 can be determined according to actual needs, so that the stroke of the pressure head can be controlled to achieve the required arc surface 2.

[0098] By setting the arc surface 2, the purpose is to reduce the stiffness of the intermediate portion, thereby reducing the stress concentration at the welding position between the turnover arm and the welded pipe after subsequent welding of the turnover arm.

[0099] The number of arc surfaces 2 can be determined according to actual needs, for example, as an example, see Figure 4 As shown, the arc surface 2 on the welded pipe 1 has one.

[0100] For another example, as another example, see Figure 5 As shown, the arc surface 2 on the welded pipe 1 has two, and the two arc surfaces 2 are arranged opposite to each other.

[0101] In addition, in order to prevent the weld 10 from being deformed during the profiling process, the weld 10 can be staggered with the arc surface 2.

[0102] For example, as an example, see Figure 4 As shown, when the arc surface 2 on the welded pipe 1 has one, the weld 10 on the welded pipe 1 is located on the opposite side of the arc surface 2.

[0103] For another example, as another example, see Figure 5 As shown, when the arc surface 2 on the welded pipe 1 has two, the two arc surfaces 2 are arranged opposite to each other, and the weld 10 on the welded pipe 1 is located between the two arc surfaces 2.

[0104] After forming the arc surface 2, see Figure 4 and Figure 5 As shown, an inside fillet with a radius R1 and an outside fillet with a radius R2 will appear on the welded pipe 1, in order to prevent wrinkles and folding defects, the inside fillet radius R1 and the outside fillet radius R2 can be controlled, for example, as an example, the inside fillet radius R1 and the outside fillet radius R2 should be greater than 1.5 times the wall thickness of the welded pipe 1.

[0105] 203: Welding a turnover arm 3 to both ends of the welded pipe 1 after profiling.

[0106] In step 203, the turnover arm 3 is made of a girder plate of 510 MPa or more, specifically, the preparation method of the turnover arm 3 is as follows:

[0107] The turnover arm 3 is made by blanking and stamping a girder plate with a tensile strength of 510 MPa or more.

[0108] The specific composition of the girder plate of 510 MPa or more can be determined according to actual needs, for example, as an example, the existing girder plate of 510 MPa or more can be used, which will not be described here.

[0109] The blanking and stamping steps can be performed using existing process conditions, so they will not be described in detail here.

[0110] 204: The welded pipe 1 is subjected to heat treatment to obtain a front suspension lateral stabilizer bar assembly; wherein the heat treatment includes: holding at 600℃~630℃ for 20min~40min, and then air cooling to room temperature.

[0111] In step 204, the welded pipe 1 is subjected to heat treatment. The purpose of this heat treatment is to eliminate the internal stress of the welded pipe 1, increase the hardness of the heat-affected zone of the weld, and increase the hardness of the heat-affected zone at the weld between the welded pipe 1 and the flipping arm 3, so as to improve the yield strength and yield strength ratio of the welded pipe 1.

[0112] To strengthen the connection between welded pipe 1 and tilting arm 3, see Figure 6 and Figure 7 As shown, before heat treatment of the welded pipe 1, the manufacturing method further includes:

[0113] A reinforcing plate 4 is welded at the welding point between the welded pipe 1 and the flipping arm 3.

[0114] The method for preparing the reinforcing plate 4 is as follows: blanking and stamping of a beam plate with a strength of 510MPa or above to obtain the reinforcing plate 4.

[0115] The specific composition of the 510MPa grade and above girder slabs can be determined according to actual needs. For example, existing 510MPa grade and above girder slabs can be used as an example, which will not be elaborated here.

[0116] The blanking and stamping steps can be performed using existing process conditions, so they will not be described in detail here.

[0117] See Figure 7 As shown, the length L from the arc surface 2 on the welded pipe 1 to the end of the welded pipe 1 and the height H of the reinforcing plate 4 satisfy: L / H≥1.5.

[0118] The purpose of designing the above-mentioned constraints is to ensure, on the one hand, that the reinforcing plate 4 has sufficient welding connection area on the welded pipe 1, and on the other hand, to ensure that the welding area between the reinforcing plate 4 and the welded pipe 1 does not affect the arc surface 2.

[0119] It should be noted that the length L from the arc surface 2 on the welded pipe 1 to the end of the welded pipe 1 is the length of the unformed portion on one side of the welded pipe 1.

[0120] The height H of the aforementioned reinforcing plate 4 is the projected length of the reinforcing plate 4 on the welded pipe 1.

[0121] See Figure 6 and Figure 7As shown, the embodiment of the present application also provides a front suspension transverse stabilizer assembly, which is manufactured by the manufacturing method of the front suspension transverse stabilizer assembly mentioned above.

[0122] Embodiment 1:

[0123] The composition of the 850MPa grade hot-rolled high-strength steel is detected, and the detection result is shown in Table 1, and the actual measured strength is Rel = 815MPa, Rm = 872MPa, and A = 21%.

[0124] Table 1 Composition of 850MPa grade hot-rolled high-strength steel (wt. %)

[0125]

[0126]

[0127] Since plastic deformation occurs from the steel plate to the steel pipe, but the plastic deformation amount of the steel pipe is difficult to measure, the plate material is used for pre-stretching test and speculation in the embodiment of the present application.

[0128] The above-mentioned 850MPa grade hot-rolled high-strength steel is used as the test steel, and the flat plate samples 14 are taken along the rolling direction of the 850MPa grade hot-rolled high-strength steel, which are divided into 7 groups, each group has 2 pieces, numbered 1#-7#, wherein 1# and 2# flat plate samples do not perform pre-stretching test, the pre-stretching deformation amount of 3# and 4# flat plate samples is 2%. The pre-stretching deformation amount of 5#, 6# and 7# three groups of flat plate samples is 3%, 4% and 5% respectively, and then 2#-7# are respectively kept at 600℃ or 620℃ for 20min, and air-cooled to room temperature. Figure 8 The mechanical properties of the test steel in different states are detected according to GB / T228.1-2010, and the detection result is shown in Table 2.

[0129] Table 2 Mechanical property detection results of test steel in different states

[0130]

[0131] It should be noted that in the above Table 2, the yield strength A is the data detected before pre-stretching or after pre-stretching and before heat treatment, and the yield strength B is the data detected after heat treatment.

[0132]

[0133] ​From Table 2, it can be seen that, after no pre-stretching or pre-stretching and without heat treatment, the detected yield strength A is normally changed within a certain range and is greater than 780 MPa, and after heat treatment, the detected yield strength B is improved, and the size of the yield strength B gradually increases with the pre-stretching deformation.

[0134] It can be inferred that, for the test steel, after cold bending forming, if no heat treatment is performed, the yield strength of the front suspension transverse stabilizer obtained is lower than that of the front suspension transverse stabilizer obtained after heat treatment.

[0135] Therefore, the application finally provides a heat treatment step, and the heat treatment has a significant strain aging strengthening effect on the test steel. Under certain heat treatment conditions, the yield strength of the test steel increases with the increase of the pre-stretching deformation, and the tensile strength and the elongation A50 do not change significantly.

[0136] Due to the heat treatment, the yield strength of the test steel increases with the increase of the pre-stretching deformation, and the tensile strength does not change significantly, thereby making the yield strength ratio have an increasing trend. The yield strength ratio data of the 1# to 7# flat plate samples can be compared.

[0137] The above-mentioned 850 MPa grade hot-rolled high-strength steel is used as the test steel, cold bending forming + high-frequency induction resistance welding is adopted to prepare a welded pipe with a specification of Φ58x4.0, two sections of the welded pipe are taken, one section of the welded pipe is not heat treated, and the other section of the welded pipe is heat treated at 620℃ for 20 min and then air-cooled to room temperature. Figure 9 (Wherein, the size unit is mm, and R represents the transition section corner radius) two tensile samples are taken from the welded pipe, numbered 8#, and the mechanical properties are detected according to GB / T228.1-2010, and the other section of the welded pipe is heat treated at 620℃ for 20 min and then air-cooled to room temperature. Figure 9 Two tensile samples are taken from the welded pipe, numbered 9#, and the mechanical properties are detected according to GB / T228.1-2010, and the detection results are shown in Table 3.

[0138] Table 3 Mechanical property detection results of the test steel in different states

[0139]

[0140] As can be seen from Table 3, compared with the 1# flat sample without pre-stretching, the tensile strength of the 8# stretched sample is increased by 102 MPa by adopting cold bending forming pipe to make it plastically deform, which is because the material appears work hardening due to plastic deformation during cold bending into a pipe. The yield strength does not change significantly, which is because the yield strength is related to the critical stress of dislocation movement. Although dislocation movement occurs during plastic deformation, there is no new factor (grain refinement, second phase precipitates) to hinder dislocation movement, so the critical stress of dislocation movement does not change, and the yield strength also does not change significantly.

[0141] After 620℃ heat preservation for 20 min, the tensile strength of the test steel is reduced by 70 MPa compared with the 8# stretched sample, which indicates that a part of the internal stress generated by plastic deformation is eliminated after heat treatment. The yield strength is increased by 80 MPa, and the yield strength ratio is increased from 0.834 to 0.987, which indicates that the deformation resistance of the test steel is improved, and it is not easy to be damaged, which can improve the anti-bumping ability during driving and improve the comfort.

[0142] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0143] It should be noted that in the present application, relationship terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitation, the element defined by the sentence "including a…" does not exclude the presence of other identical elements in the process, method, article or equipment including the element.

[0144] The foregoing detailed description of the application has been presented for purposes of illustration and description. Various modifications and changes can be made to these embodiments without departing from the spirit and scope of the application. It is intended that the scope of the application should not be limited by the particular representative embodiments described above.

Claims

1. A method of manufacturing a front-suspension transverse stabilizer bar, characterized by, It comprises the following steps: The 850MPa hot-rolled high-strength steel is cold-bent and formed, and welded to obtain a welded pipe (1); The middle part of the welded pipe (1) is subjected to profiling treatment to form a camber surface (2) on the welded pipe (1); The welded pipe (1) subjected to the profiling treatment is subjected to heat treatment to obtain the front-suspended transverse stabilizer; The heat treatment comprises: keeping the temperature at 600-630℃ for 20-40min; According to the mass fraction, the chemical composition of the 850MPa hot-rolled high-strength steel comprises: C≤0.10%, Si≤0.20%, Mn≤1.80%, P≤0.025%, S≤0.015%, Nb≤0.22%, V≤0.22%, Ti≤0.22%, Al≤0.05%, Mo≤0.50%, and the rest is Fe and inevitable impurity elements; And / or, the coiling temperature of the 850MPa hot-rolled high-strength steel is 550-600℃; And / or, the yield strength of the 850MPa hot-rolled high-strength steel is ≥780MPa, the tensile strength is ≥850MPa, and the elongation A50 is ≥15%; And / or, the yield strength of the welded pipe (1) is ≥800MPa, the tensile strength is ≥870MPa, and the elongation A is ≥7.5%; And / or, the welded pipe (1) is obtained by high-frequency induction resistance welding; And / or, the welded pipe (1) has one camber surface (2), and the weld (10) on the welded pipe (1) is located on the opposite side of the camber surface (2); or the welded pipe (1) has two camber surfaces (2), the two camber surfaces (2) are arranged opposite to each other, and the weld (10) on the welded pipe (1) is located between the two camber surfaces (2); The welded pipe (1) is also subjected to profiling treatment to form a camber surface, thereby reducing the rigidity of the middle part and reducing the stress concentration between the welded part of the welded pipe (1) and the turnover arm after the turnover arm is welded.

2. A front wishbone stabilizer bar characterized by: It is manufactured by using the manufacturing method of the front-suspended transverse stabilizer according to claim 1.

3. A method of manufacturing a front-suspension transverse stabilizer bar assembly, characterized by, It comprises the following steps: The 850MPa hot-rolled high-strength steel is cold-bent and formed, and welded to obtain a welded pipe (1); The middle part of the welded pipe (1) is subjected to profiling treatment to form a camber surface (2) on the welded pipe (1); The two ends of the welded pipe (1) subjected to the profiling treatment are welded with turnover arms (3); The welded pipe (1) is subjected to heat treatment to obtain a front-suspended transverse stabilizer assembly; The heat treatment comprises: keeping the temperature at 600-630℃ for 20-40min; According to the mass fraction, the chemical composition of the 850MPa hot-rolled high-strength steel comprises: C≤0.10%, Si≤0.20%, Mn≤1.80%, P≤0.025%, S≤0.015%, Nb≤0.22%, V≤0.22%, Ti≤0.22%, Al≤0.05%, Mo≤0.50%, and the rest is Fe and inevitable impurity elements; And / or, the coiling temperature of the 850MPa hot-rolled high-strength steel is 550-600℃; And / or, the yield strength of the 850MPa hot-rolled high-strength steel is ≥780MPa, the tensile strength is ≥850MPa, and the elongation A50 is ≥15%. And / or, the yield strength of the 850MPa-grade hot-rolled high-strength steel is ≥780MPa, the tensile strength is ≥850MPa, and the elongation A50 is ≥15%; And / or, the yield strength of the welded pipe (1) is ≥800MPa, the tensile strength is ≥870MPa, and the elongation A is ≥7.5%; And / or, the welded pipe (1) is made by high-frequency induction resistance welding; And / or, the welded pipe (1) has one arc surface (2), and the weld (10) on the welded pipe (1) is located on the opposite side of the arc surface (2); or, the welded pipe (1) has two arc surfaces (2), the two arc surfaces (2) are arranged opposite to each other, and the weld (10) on the welded pipe (1) is located between the two arc surfaces (2); The welded pipe (1) is also subjected to profiling treatment to form an arc surface, thereby reducing the rigidity of the middle part and reducing the stress concentration between the turning arm and the welded pipe (1) after the turning arm is welded.

4. The method of manufacturing a front-suspension transverse stabilizer bar assembly of claim 3, wherein, The manufacturing method further comprises: Blanking and stamping the girder plate of 510MPa or above to obtain the turning arm (3).

5. The method of manufacturing a front-suspension transverse stabilizer bar assembly of claim 3, wherein, Before the welded pipe (1) is subjected to heat treatment, the manufacturing method further comprises: Welding a reinforcing plate (4) at the welding position of the welded pipe (1) and the turning arm (3).

6. The method of manufacturing a front-suspension transverse stabilizer bar assembly of claim 5, wherein, The manufacturing method further comprises: Blanking and stamping the girder plate of 510MPa or above to obtain the reinforcing plate (4).

7. The manufacturing method of the front suspension transverse stabilizer bar assembly according to claim 5, characterized in that: The length L of the arc surface (2) on the welded pipe (1) to the end of the welded pipe (1) and the height H of the reinforcing plate (4) satisfy: L / H≥1.

5.

8. A front sway bar assembly characterized by: The front suspension transverse stabilizer bar assembly is manufactured by the manufacturing method according to any one of claims 3-7.

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