A method and device for detecting internal stress of hot-rolled H-shaped steel by double-hole method

Abstract

The application discloses a hot-rolled H-shaped steel inner stress double-hole detection method and device, belongs to the technical field of hot-rolled H-shaped steel production, and is characterized in that under different temperature conditions, transverse double-hole punching and / or longitudinal double-hole punching are respectively performed on the r-round corner of the hot-rolled H-shaped steel, the crack and fracture between the two holes are observed, and the grade of the hot-rolled H-shaped steel is evaluated according to the crack and fracture between the two holes. The application has the beneficial effect that the stress at the R-round corner where the stress of the hot-rolled H-shaped steel is concentrated is released through the double-hole method, the crack and fracture crack between the two holes of the steel matrix occur, the grade of the hot-rolled H-shaped steel is evaluated according to the crack and fracture between the two holes, the hot-rolled H-shaped steel that does not meet the standard is identified, and therefore the safe service performance of the steel member made of the whole hot-rolled H-shaped steel is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hot-rolled H-shaped steel production, in particular to a hot-rolled H-shaped steel internal stress double-hole method detection method and device. BACKGROUND

[0002] Large inclusions in the hot-rolled H-shaped steel base are unevenly distributed and concentrated, and the inclusions initiate crack sources, causing continuous damage to the steel base. Moreover, the crack can propagate under a stress lower than the yield stress. During the service process of the hot-rolled H-shaped steel, the yield caused by various loads leads to further expansion of the crack to the surface layer of the steel base, and r-round corner cracks occur or the hot-rolled H-shaped steel breaks, resulting in strength failure of the hot-rolled H-shaped steel and collapse of the steel structure. The r-round corner is the intersection of the flange and the web of the hot-rolled H-shaped steel, which is at risk of internal defects such as steel inclusions and sharp crack tip stress concentration. At present, there is no related method and equipment for detecting the stress at the r-round corner of the hot-rolled H-shaped steel, which brings great safety hazards to the service of the steel structure made of the hot-rolled H-shaped steel.

[0003] The drilling method was first proposed by JMathar in 1934, and then developed and perfected by Soete to form a systematic theory. The basic principle is to drill a small hole on the surface of a component with residual stress, so that the adjacent area of the hole produces corresponding displacement and strain due to partial stress release, and the displacement and strain are measured by means of sticking strain gauges, etc. Finally, the average residual stress at the drilling depth can be obtained through conversion. The disadvantages are: (1) long time-consuming, tedious work for the detection personnel, and not intuitive, which cannot meet the on-site rapid detection of internal stress in the production workshop; (2) no detection for the stress concentrated r-round corner of the hot-rolled H-shaped steel product.

[0004] In view of this, the present inventors have carried out in-depth research on this demand, and thus the present application is produced. SUMMARY

[0005] In order to overcome the problem that there is no related method and equipment for detecting the stress at the r-round corner of the hot-rolled H-shaped steel in the prior art, which brings great safety hazards to the service of the steel structure made of the hot-rolled H-shaped steel, the present application provides a hot-rolled H-shaped steel internal stress double-hole method detection method, which adopts the method of drilling two holes, reverses the process, releases the stress at the R-round corner where the stress of the hot-rolled H-shaped steel is concentrated, causes cracks and fracture cracks in the steel base between the two holes, and even penetrates the two holes, so as to detect the problem of rapid pre-evaluation of the r-round corner inclusion concentration where the stress is most concentrated and whether the internal stress of the hot-rolled H-shaped steel exists. The specific technical scheme is as follows:

[0006] Under different temperature conditions, transverse double-hole drilling and / or longitudinal double-hole drilling are performed on the r-round corner of the hot-rolled H-shaped steel, and the crack and fracture between the two holes are observed;

[0007] The grade of the hot-rolled H-shaped steel is evaluated according to the crack and fracture between the two holes.

[0008] The stress at the R-round corner of the hot-rolled H-shaped steel is released by the double-hole method, causing the crack and fracture between the steel matrix of the double holes to occur, and the grade of the hot-rolled H-shaped steel is evaluated according to the crack and fracture between the two holes, so that the hot-rolled H-shaped steel that does not meet the standard is identified, thereby improving the safe service performance of the steel structure of the entire hot-rolled H-shaped steel.

[0009] Preferably, the transverse double-hole punching and / or longitudinal double-hole punching is performed on the R-round corner of the hot-rolled H-shaped steel at 20℃, 0℃, -20℃ and -40℃, respectively, and the crack and fracture between the two holes are observed.

[0010] Preferably, the transverse double-hole punching refers to that the straight line where the center line of the two holes is located is perpendicular to the rolling direction of the hot-rolled H-shaped steel.

[0011] The longitudinal double-hole punching refers to that the straight line where the center line of the two holes is located is parallel to the rolling direction of the hot-rolled H-shaped steel.

[0012] The angle between the punching direction of the transverse double-hole punching and the longitudinal double-hole punching and the plane where the web of the hot-rolled H-shaped steel is located is 30-60°.

[0013] Preferably, in the transverse double-hole punching and the longitudinal double-hole punching, the distance between the two holes is 15mm, and the hole diameter of the two holes is 5mm.

[0014] Preferably, the grade of the hot-rolled H-shaped steel is evaluated according to the average length Lm of the longer crack, the number N of cracks and the maximum length Ln of the crack between the two holes.

[0015] The average length Lm of the longer crack refers to the average length of a part of cracks ranked in the front in the crack length.

[0016] Preferably, when there is no crack between the two holes, the grade of the hot-rolled H-shaped steel is D1.

[0017] When there is a crack between the two holes, the number N of cracks is less than 20, the average length Lm of the longer crack is less than R, and the maximum length Ln of the crack between the two holes is less than (L-2R) / 4, the grade of the hot-rolled H-shaped steel is D2.

[0018] When there is a crack between the two holes, the number N of cracks is less than 20, the average length Lm of the longer crack satisfies R≤Lm≤2R, and the maximum length Ln of the crack between the two holes is less than (L-2R) / 2, the grade of the hot-rolled H-shaped steel is D3.

[0019] When there are cracks between the two holes, the number of cracks N is less than 20, the average length of the longer cracks Lm is less than R, and the maximum length of the cracks between the two holes Ln satisfies (L-2R) / 4≤Ln≤(L-2R) / 2, the grade of the hot-rolled H-shaped steel is D3;

[0020] When there are cracks between the two holes, the number of cracks N is less than 20, the average length of the longer cracks Lm is less than R, and the maximum length of the cracks between the two holes Ln is greater than (L-2R) / 2, the grade of the hot-rolled H-shaped steel is D4;

[0021] When there are cracks between the two holes, the number of cracks N is less than 20, the average length of the longer cracks Lm satisfies R≤Lm≤2R, and the maximum length of the cracks between the two holes Ln is not less than (L-2R) / 2, the grade of the hot-rolled H-shaped steel is D4;

[0022] When the number of cracks N between the two holes is not less than 20, the grade of the hot-rolled H-shaped steel is D5;

[0023] When there are cracks between the two holes, the number of cracks N is less than 20, the average length of the longer cracks Lm is greater than 2R, and the maximum length of the cracks between the two holes is not less than (L-2R) / 2, the grade of the hot-rolled H-shaped steel is D5;

[0024] When the cracks between the two holes are connected, the grade of the hot-rolled H-shaped steel is D5;

[0025] Wherein the average length of the longer cracks Lm refers to the average length of the maximum number of cracks in the top half of the cracks;

[0026] Wherein L is the intermediate distance between the two holes, and R is the hole radius of the two holes.

[0027] Preferably, wherein the grades of the hot-rolled H-shaped steel are D1 and D2, which means that the hot-rolled H-shaped steel is a qualified product, D3 means that the hot-rolled H-shaped steel is an unqualified product, and D4 and D5 mean that the hot-rolled H-shaped steel is a waste product.

[0028] The present application also provides a hot-rolled H-shaped steel internal stress double-hole detection device, which adopts the above-mentioned hot-rolled H-shaped steel internal stress double-hole detection method, and comprises a rack, a drill mechanism and a hot-rolled H-shaped steel mounting mechanism, wherein the drill mechanism and the hot-rolled H-shaped steel mounting mechanism are both fixedly installed on the rack, the direction of the drill of the drill mechanism is perpendicular to the length direction of the hot-rolled H-shaped steel, and the direction of the drill of the drill mechanism is opposite to the hot-rolled H-shaped steel mounting mechanism.

[0029] The drill mechanism and the hot-rolled H-shaped steel mounting mechanism are used in cooperation, the drill is adjusted to the position to be drilled of the hot-rolled H-shaped steel, the double-hole drilling of the hot-rolled H-shaped steel is completed, and the unqualified hot-rolled H-shaped steel is identified according to the double-hole cracks and the broken cracks.

[0030] Preferably, the drill head mechanism comprises a drill head, a drill head feed assembly for controlling the feed of the drill head in the length direction of the drill head, and a translation assembly for controlling the left and right movement of the drill head.

[0031] The drill head feed assembly comprises a motor, a floating screw rod and a drill bed base, the motor is fixedly installed on the lower surface of the frame, one end of the floating screw rod is fixedly installed on the movable end of the motor, and the other end is rotatably installed on the frame; the drill bed base is threadedly connected to the floating screw rod and can move back and forth along the length direction of the floating screw rod, and the upper part of the drill bed base is arranged on the upper surface of the frame through a sliding groove located on the surface of the frame; the translation assembly is installed on the upper surface of the drill bed base.

[0032] The translation assembly comprises a drill bed small base, a rotating hand wheel, a translation transmission structure and a sliding rail, the sliding rail is fixedly installed on the upper surface of the drill bed base and is perpendicular to the length direction of the floating screw rod; the drill bed small base is slidingly installed on the sliding rail, the rotating hand wheel is arranged on one side of the drill bed small base, and the translation transmission structure is arranged at the output end of the rotating hand wheel and located inside the drill bed small base.

[0033] Preferably, the hot-rolled H-shaped steel installation mechanism comprises a hydraulic clamping clamp, a steel rotation assembly for controlling the rotation of the hot-rolled H-shaped steel along the length direction of the hot-rolled H-shaped steel as the axis, and a steel lifting assembly for controlling the lifting of the hot-rolled H-shaped steel along the length direction of the hot-rolled H-shaped steel.

[0034] The steel rotation assembly comprises a rotating hydraulic drive motor, a rotating gear and a steel containing sleeve, the rotating hydraulic drive motor is fixedly installed on the steel lifting assembly, the rotating gear is fixedly installed on the output end of the rotating hydraulic drive motor, the inner wall of the steel containing sleeve is formed with an internal gear, the rotating gear is engaged with the internal gear on the inner wall of the steel containing sleeve, and the hydraulic clamping clamp is fixedly installed in the steel containing sleeve.

[0035] The steel lifting assembly comprises a lifting hydraulic drive motor, a driving lifting gear and a driven lifting gear, the lifting hydraulic drive motor is fixedly installed on the frame, the center of the driving lifting gear is fixedly installed on the output end of the lifting hydraulic drive motor, the outer wall of the steel containing sleeve is formed with an external gear rack, the driving lifting gear is engaged with the external gear rack on the outer wall of the steel containing sleeve, and the driven lifting gear is located on the side of the steel containing sleeve away from the driving lifting gear and is engaged with the external gear rack on the outer wall of the steel containing sleeve.

[0036] Beneficial effects:

[0037] The beneficial effects produced by adopting the technical scheme of the present application are as follows:

[0038] Beneficial effects:

[0037] The beneficial effects produced by adopting the technical scheme of the present application are as follows:

[0038] (1) Through the double-hole method, the stress concentration R of the hot-rolled H-shaped steel is released, the crack and fracture crack between the double holes are caused, and the grade of the hot-rolled H-shaped steel is evaluated according to the crack and fracture between the two holes, and the hot-rolled H-shaped steel that does not meet the standard is identified, thereby improving the safe service performance of the whole hot-rolled H-shaped steel structure.

[0039] (2) The drill mechanism cooperates with the hot-rolled H-shaped steel installation mechanism, adjusts the drill bit to the position to be drilled of the hot-rolled H-shaped steel, completes the double-hole drilling of the hot-rolled H-shaped steel, and identifies the hot-rolled H-shaped steel that does not meet the standard according to the double-hole crack and fracture crack. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0041] Figure 1 It is a preferred double-hole method for detecting internal stress of the hot-rolled H-shaped steel of the present application;

[0042] Figure 2 It is a preferred longitudinal double-hole punching sectional view of the hot-rolled H-shaped steel of the present application;

[0043] Figure 3 It is a preferred transverse double-hole punching sectional view of the hot-rolled H-shaped steel of the present application;

[0044] Figure 4 It is a preferred structure diagram corresponding to the grade D1 and D2 of the crack and fracture between the two holes of the present application;

[0045] Figure 5 It is a preferred structure diagram corresponding to the grade D3, D4 and D5 of the crack and fracture between the two holes of the present application;

[0046] Figure 6 It is a preferred side view structure diagram of the double-hole method for detecting internal stress of the hot-rolled H-shaped steel of the present application;

[0047] Figure 7 It is a preferred top view structure diagram of the double-hole method for detecting internal stress of the hot-rolled H-shaped steel of the present application. DETAILED DESCRIPTION

[0048] In order to make the purposes, 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 in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0049] The hot-rolled H-shaped steel internal stress double-hole method detection method in the embodiment releases stress at the R-round corner where stress is concentrated in the hot-rolled H-shaped steel in advance by means of double-hole drilling, causes cracks and fracture cracks of the steel matrix between the double holes to occur, and even penetrates the double holes, so as to detect whether the r-round corner inclusion concentration is fast pre-evaluated and whether the hot-rolled H-shaped steel internal stress exists. The specific technical solutions are as follows:

[0050] As shown in Figure 1 , a hot-rolled H-shaped steel internal stress double-hole method detection method,

[0051] Step S101, transverse double-hole drilling and / or longitudinal double-hole drilling are respectively performed on the r-round corner of the hot-rolled H-shaped steel under different temperature conditions;

[0052] Step S102, cracks and fracture between the two holes are observed;

[0053] Step S103, the grade of the hot-rolled H-shaped steel is evaluated according to the cracks and fracture between the two holes.

[0054] The stress at the R-round corner where stress is concentrated in the hot-rolled H-shaped steel is released by means of double-hole method, cracks and fracture cracks of the steel matrix between the double holes are caused to occur, and the grade of the hot-rolled H-shaped steel is evaluated according to the cracks and fracture between the two holes, so that the hot-rolled H-shaped steel that does not meet the standard is identified, thereby improving the safe service performance of the steel member made of the entire hot-rolled H-shaped steel.

[0055] As a preferred embodiment, transverse double-hole drilling and / or longitudinal double-hole drilling is respectively performed on the r-round corner of the hot-rolled H-shaped steel at 20℃, 0℃, -20℃ and -40℃, and cracks and fracture between the two holes are observed.

[0056] As a preferred embodiment, the transverse double-hole drilling refers to that the straight line where the connecting line of the centers of the two holes is located is perpendicular to the rolling direction of the hot-rolled H-shaped steel;

[0057] The longitudinal double-hole drilling refers to that the straight line where the connecting line of the centers of the two holes is located is parallel to the rolling direction of the hot-rolled H-shaped steel;

[0058] As shown in Figure 2 and 3 , respectively, are cross-sectional views of a longitudinal double-hole punching and a transverse double-hole punching, in which r-rounding 100 is the intersection of a hot-rolled H-shaped steel flange 110 and a web 120. The angle between the punching direction of the transverse double-hole punching and the longitudinal double-hole punching and the plane in which the hot-rolled H-shaped steel web lies is 30-60°, forming holes 130.

[0059] As a preferred embodiment, in the transverse double-hole punching and the longitudinal double-hole punching, the double-hole intermediate spacing is 15 mm, and the hole diameter of the double holes is 5 mm.

[0060] As a preferred embodiment, the grade of the hot-rolled H-shaped steel is evaluated according to the longer crack average length Lm, the crack number N, and the longest crack length Ln of the inter-hole cracks;

[0061] wherein the longer crack average length Lm refers to the average length of a portion of cracks ranked high in crack length.

[0062] As a preferred embodiment, as shown in Figure 4 and 5 , when there are no inter-hole cracks, the grade of the hot-rolled H-shaped steel is D1;

[0063] When there are inter-hole cracks and the crack number N is less than 20, the longer crack average length Lm is less than R, and the maximum length Ln of the inter-hole cracks is less than (L-2R) / 4, the grade of the hot-rolled H-shaped steel is D2;

[0064] When there are inter-hole cracks and the crack number N is less than 20, the longer crack average length Lm satisfies R≤Lm≤2R, and the maximum length Ln of the inter-hole cracks is less than (L-2R) / 2, the grade of the hot-rolled H-shaped steel is D3;

[0065] When there are inter-hole cracks and the crack number N is less than 20, the longer crack average length Lm is less than R, and the maximum length Ln of the inter-hole cracks satisfies (L-2R) / 4≤Ln≤(L-2R) / 2, the grade of the hot-rolled H-shaped steel is D3;

[0066] When there are inter-hole cracks and the crack number N is less than 20, the longer crack average length Lm is less than R, and the maximum length Ln of the inter-hole cracks is greater than (L-2R) / 2, the grade of the hot-rolled H-shaped steel is D4;

[0067] When there are inter-hole cracks and the crack number N is less than 20, the longer crack average length Lm satisfies R≤Lm≤2R, and the maximum length Ln of the inter-hole cracks is not less than (L-2R) / 2, the grade of the hot-rolled H-shaped steel is D4;

[0068] When the number of cracks N between the two holes is not less than 20, the hot-rolled H-shaped steel is rated as D5;

[0069] When there are cracks between the two holes, the number of cracks N is less than 20, the average length of the longer cracks Lm is greater than 2R, and the maximum length of the cracks between the two holes is not less than (L-2R) / 2, the hot-rolled H-shaped steel is rated as D5;

[0070] When there are cracks between the two holes, the number of cracks N is less than 20, the average length of the longer cracks Lm is greater than 2R, and the maximum length of the cracks between the two holes is not less than (L-2R) / 2, the hot-rolled H-shaped steel is rated as D5;

[0071] Wherein the average length of the longer cracks Lm refers to the average length of the maximum number of cracks in the top half of the crack length ranking;

[0072] Wherein L is the intermediate distance between the two holes, and R is the hole radius of the two holes.

[0073] As a preferred embodiment, wherein the grades of the hot-rolled H-shaped steel are D1 and D2, indicating that the hot-rolled H-shaped steel is a qualified product, D3 indicates that the hot-rolled H-shaped steel is a substandard product, and D4 and D5 indicate that the hot-rolled H-shaped steel is a waste product.

[0074] As shown in Figure 6 and 7 The present embodiment also provides a hot-rolled H-shaped steel internal stress double-hole detection device, which adopts the hot-rolled H-shaped steel internal stress double-hole detection method described above, and comprises a rack 1, a drill mechanism 2 and a hot-rolled H-shaped steel mounting mechanism 3. The drill mechanism 2 and the hot-rolled H-shaped steel mounting mechanism 3 are both fixedly installed on the rack 1, the drill direction of the drill mechanism 2 is perpendicular to the length direction of the hot-rolled H-shaped steel 101, and the drill direction of the drill mechanism 2 is directly opposite to the hot-rolled H-shaped steel 101 mounting mechanism.

[0075] The drill mechanism cooperates with the hot-rolled H-shaped steel mounting mechanism, the drill is adjusted to the position to be drilled of the hot-rolled H-shaped steel, the double-hole drilling of the hot-rolled H-shaped steel is completed, and the substandard hot-rolled H-shaped steel is identified according to the double-hole cracks and the broken cracks.

[0076] Wherein, the drill mechanism 2 comprises a drill 21, a drill feeding assembly 22 for controlling the drill 21 to feed in the length direction of the drill, and a translation assembly 23 for controlling the left and right movement of the drill 21;

[0077] The drill bit feeding assembly 22 comprises a motor 221 fixedly installed on the lower surface of the frame 1, a movable screw rod 222 fixedly installed on the movable end of the motor 221 and rotatably installed on the frame 1, and a drill bed base 223 threadedly connected to the movable screw rod 222 and movable along the length direction of the movable screw rod 222, the upper part of the drill bed base 223 being arranged on the upper surface of the frame 1 through the sliding groove 11 on the surface of the frame 1, and the translation assembly 23 being installed on the upper surface of the drill bed base 223;

[0078] The translation assembly 23 comprises a drill bed small base 231, a rotating hand wheel 232, a translation transmission structure (not shown in the figure) and a sliding rail 233 fixedly installed on the upper surface of the drill bed base 223 and perpendicular to the length direction of the movable screw rod 222, the drill bed small base 231 being slidably installed on the sliding rail 233, the rotating hand wheel 232 being arranged on one side of the drill bed small base 231, the translation transmission structure being arranged at the output end of the rotating hand wheel 232 and inside the drill bed small base 231, and the drill bit 21 being fixedly installed on the side of the drill bed small base 231 close to the hot-rolled H-shaped steel mounting mechanism 3, wherein the translation transmission structure drives the drill bed small base 231 to move back and forth along the sliding rail 233 with the rotation of the rotating hand wheel 232, and many structures achieving this function are available in the prior art, which will not be described here.

[0079] The hot-rolled H-shaped steel mounting mechanism 3 comprises a hydraulic clamping clamp 31, a steel rotating assembly 32 for controlling the hot-rolled H-shaped steel 101 to rotate with the length direction as the axis, and a steel lifting assembly 33 for controlling the hot-rolled H-shaped steel 101 to lift along the length direction.

[0080] The steel rotating assembly 32 comprises a rotating hydraulic drive motor (not shown in the figure), a rotating gear 322 and a steel containing sleeve 323, the rotating hydraulic drive motor 321 being fixedly installed on the steel lifting assembly 33, the rotating gear 322 being fixedly installed on the output end of the rotating hydraulic drive motor 321, the inner wall of the steel containing sleeve 323 being formed with an internal gear 324, the rotating gear 322 being engaged with the internal gear 324 on the inner wall of the steel containing sleeve 323, and the hydraulic clamping clamp 31 being fixedly installed in the steel containing sleeve 323.

[0081] The profile steel lifting assembly 33 comprises a lifting hydraulic drive motor 331 fixedly installed on the frame 1, a driving lifting gear (not shown in the figure) and a passive lifting gear 333. The driving lifting gear is fixedly installed at the output end of the lifting hydraulic drive motor 331. An external rack 325 is formed on the outer wall of the profile steel containing sleeve 323. The driving lifting gear is engaged with the external rack 325 on the outer wall of the profile steel containing sleeve 323. The passive lifting gear 333 is located on the side of the profile steel containing sleeve 323 away from the driving lifting gear and is engaged with the external rack 325 on the outer wall of the profile steel containing sleeve 323.

[0082] The frame 1 is further provided with an electric control box 12 and a hydraulic station 13 for controlling the lifting hydraulic drive motor and the rotating hydraulic drive motor.

[0083] The hot-rolled H-shaped steel internal stress detection punching equipment and the refrigerator can realize sample transverse double-hole detection and longitudinal double-hole detection at different temperatures, thereby realizing detection of the internal stress of the hot-rolled H-shaped steel product at different temperatures (the ductile-brittle transition temperature of the steel). The double-hole test method is used to detect the internal stress of the hot-rolled H-shaped steel product at different temperatures. The existence, size and presence or absence of the internal stress of the product are judged by observing the cracks and fracture cracks between the double holes, which is convenient, fast and low in cost.

[0084] The above only describes the preferred embodiments of the present application and is not used to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for detecting internal stress of a hot-rolled H-beam by a double-hole method, the method comprising: performing transverse double-hole drilling and / or longitudinal double-hole drilling on a r-round corner of the hot-rolled H-beam at different temperatures, and observing cracks and fractures between the two holes; the transverse double-hole drilling refers to a straight line where a connecting line of centers of the two holes is perpendicular to a rolling direction of the hot-rolled H-beam; the longitudinal double-hole drilling refers to a straight line where a connecting line of centers of the two holes is parallel to the rolling direction of the hot-rolled H-beam; and evaluating a grade of the hot-rolled H-beam according to the cracks and fractures between the two holes, including: evaluating the grade of the hot-rolled H-beam according to a longer crack average length Lm, a crack number N, and a longest crack length Ln between the two holes; when there is no crack between the two holes, the grade of the hot-rolled H-beam is D1; when there is a crack between the two holes, the crack number N is less than 20, the longer crack average length Lm is less than R, and the longest crack length Ln between the two holes is less than (L-2R) / 4, the grade of the hot-rolled H-beam is D2; when there is a crack between the two holes, the crack number N is less than 20, the longer crack average length Lm satisfies R≤Lm≤2R, and the longest crack length Ln between the two holes is less than (L-2R) / 2, the grade of the hot-rolled H-beam is D3; when there is a crack between the two holes, the crack number N is less than 20, the longer crack average length Lm is less than R, and the longest crack length Ln between the two holes satisfies (L-2R) / 4≤Ln≤(L-2R) / 2, the grade of the hot-rolled H-beam is D3; when there is a crack between the two holes, the crack number N is less than 20, the longer crack average length Lm is less than R, and the longest crack length Ln between the two holes is greater than (L-2R) / 2, the grade of the hot-rolled H-beam is D4; when there is a crack between the two holes, the crack number N is less than 20, the longer crack average length Lm satisfies R≤Lm≤2R, and the longest crack length Ln between the two holes is not less than (L-2R) / 2, the grade of the hot-rolled H-beam is D4; when the crack number N between the two holes is not less than 20, the grade of the hot-rolled H-beam is D5; when there is a crack between the two holes, the crack number N is less than 20, the longer crack average length Lm is greater than 2R, and the longest crack length between the two holes is not less than (L-2R) / 2, the grade of the hot-rolled H-beam is D5; when the cracks between the two holes are connected, the grade of the hot-rolled H-beam is D5; wherein the longer crack average length Lm refers to an average length of a maximum number of cracks that are not more than half of the crack number and are ranked in the front of crack length; and wherein L is a double-hole intermediate spacing, and R is a hole radius of the double hole. 2.The method according to claim 1, wherein the transverse double-hole drilling and / or the longitudinal double-hole drilling is performed on the r-round corner of the hot-rolled H-beam at 20℃, 0℃, -20℃, and -40℃. 3.The method according to claim 1, wherein an angle between a drilling direction of the transverse double-hole drilling and the longitudinal double-hole drilling and a plane where a web of the hot-rolled H-beam is located is 30-60°. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4. The method according to claim 1, wherein the method is characterized by, In the transverse double-hole punching and the longitudinal double-hole punching, the double-hole intermediate spacing is 15 mm, and the double-hole diameter is 5 mm.

5. The method of claim 1, wherein the method is a double-hole method for detecting internal stress of a hot-rolled H-beam. In the formula, the grades D1 and D2 of the hot-rolled H-shaped steel represent that the hot-rolled H-shaped steel is a qualified product, D3 represents that the hot-rolled H-shaped steel is an unqualified product, and D4 and D5 represent that the hot-rolled H-shaped steel is a waste product.

6. A hot-rolled H-beam internal stress double-hole method detection device, characterized by, The hot-rolled H-shaped steel internal stress double-hole detection method according to any one of claims 1-5 comprises a rack, a drill bit mechanism, and a hot-rolled H-shaped steel mounting mechanism, the drill bit mechanism and the hot-rolled H-shaped steel mounting mechanism are both fixedly installed on the rack, the drill bit direction of the drill bit mechanism is perpendicular to the length direction of the hot-rolled H-shaped steel, and the drill bit direction of the drill bit mechanism directly faces the hot-rolled H-shaped steel mounting mechanism.

7. The apparatus for inspecting internal stress of a hot-rolled H-beam according to claim 6, wherein The drill bit mechanism comprises a drill bit, a drill bit feeding assembly for controlling the feeding of the drill bit in the length direction of the drill bit, and a translation assembly for controlling the left-right movement of the drill bit. The drill bit feeding assembly comprises a motor, a floating screw rod, and a drill bed pedestal, the motor is fixedly installed on the lower surface of the rack, one end of the floating screw rod is fixedly installed on the movable end of the motor, and the other end is rotatably installed on the rack, the drill bed pedestal is threadedly connected to the floating screw rod and can move back and forth along the length direction of the floating screw rod, the upper part of the drill bed pedestal is arranged on the upper surface of the rack through a sliding groove located on the surface of the rack, and the translation assembly is installed on the upper surface of the drill bed pedestal. The translation assembly comprises a drill bed small pedestal, a rotating hand wheel, a translation transmission structure, and a sliding rail, the sliding rail is fixedly installed on the upper surface of the drill bed pedestal and is perpendicular to the length direction of the floating screw rod, the drill bed small pedestal is slidably installed on the sliding rail, the rotating hand wheel is arranged on one side of the drill bed small pedestal, and the translation transmission structure is arranged at the output end of the rotating hand wheel and located inside the drill bed small pedestal.

8. The apparatus for inspecting internal stress of a hot-rolled H-beam according to claim 6, wherein, The hot-rolled H-shaped steel mounting mechanism comprises a hydraulic clamping clamp, a steel rotating assembly for controlling the rotation of the hot-rolled H-shaped steel with the length direction as the axis, and a steel lifting assembly for controlling the lifting of the hot-rolled H-shaped steel along the length direction. The steel rotating assembly comprises a rotating hydraulic drive motor, a rotating gear, and a steel containing sleeve, the rotating hydraulic drive motor is fixedly installed on the steel lifting assembly, the rotating gear is fixedly installed at the output end of the rotating hydraulic drive motor, an internal gear is formed on the inner wall of the steel containing sleeve, the rotating gear is engaged with the internal gear on the inner wall of the steel containing sleeve, and the hydraulic clamping clamp is fixedly installed in the steel containing sleeve. The steel lifting assembly comprises a lifting hydraulic drive motor, a driving lifting gear, and a driven lifting gear, the lifting hydraulic drive motor is fixedly installed on the rack, the center of the driving lifting gear is fixedly installed at the output end of the lifting hydraulic drive motor, an external gear rack is formed on the outer wall of the steel containing sleeve, the driving lifting gear is engaged with the external gear rack on the outer wall of the steel containing sleeve, and the driven lifting gear is located on the side of the steel containing sleeve away from the driving lifting gear and engaged with the external gear rack on the outer wall of the steel containing sleeve.

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