JP2014014849A - Y-type welding crack testing plate, and method of manufacturing y-type welding crack testing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a y-type welding crack testing plate, and a manufacturing method thereof, for reducing welding manhours, when executing restriction welding, by accurately forming a gap of a test welding part of the y-type welding crack testing plate, without executing the restriction welding.SOLUTION: A y-type welding crack testing plate 1 comprises: a testing plate body 2 composed of a steel material; a V-shaped groove 6 formed so as to extend in a straight line shape in an area except for an edge part of a surface of the body and being a V shape of having an inclined face of crossing at an angle corresponding to a groove angle of a y-shaped groove of a testing object in a cross section in a width direction vertical to a direction of extending in the straight line shape; and a plate-like slit 11 opening on a reverse surface of the body by extending up to the reverse surface of the body from a whole area of a bottom part of the V-shaped groove 6, inclined in the same surface as one inclined face of the V-shaped groove 6 in its one surface and corresponding to a route gap of the y-shaped groove of the testing object in an interval of opposed two surfaces.

Description

  The present invention is used in the y-type weld crack test method for testing low temperature cracks generated in welds of carbon steel and low alloy steel by covered arc welding, gas shielded arc welding, and self-shielded arc welding described in JIS Z 3158. The present invention relates to a y-type weld crack test plate and a manufacturing method thereof.

  The y-type weld cracking test is a test for examining the low-temperature cracking susceptibility of a welded portion. A y-shaped groove formed on a test plate with a predetermined root gap is welded as a test welded portion, and a predetermined time (usually 48 hours). ) After progress, it is inspected whether surface cracks and cross-sectional cracks have occurred in the welded test plate.

  Conventionally, the y-type weld crack test plate 101 shown in FIG. 11A has been used for the y-type weld crack test. As shown in FIGS. 12 (a) to 12 (d), steel plates 102 and 103 having two different shapes were produced by subjecting steel plates 102 and 103 to restraint welding, leaving a test weld 104 for performing a weld cracking test. Is. Below, the manufacturing method of this conventional y-type weld crack test plate 101 is shown.

  As shown in FIGS. 12A and 12B, the steel plate 102 has a width of 200 mm, a length (75 + plate thickness t / 3.4) mm, and a plate thickness t. First, one end portion in the length direction of the steel plate 102 is cut from the surface of the steel plate 102 to one end portion in the length direction of the back surface of the steel plate 102 at an angle of 60 ° with respect to the surface of the steel plate 102 (first step). ). Next, at one end portion in the length direction of the steel plate 102, a portion from one end portion in the width direction of the steel plate 102 to a direction 60 mm parallel to the width direction of the steel plate 102 is taken from the back surface of the steel plate 102 in the thickness direction of the steel plate 102. Is cut at an angle of 60 ° with respect to the back surface of the steel plate 102 up to one end portion in the length direction of the steel plate 102 in the half portion (second step). Similarly, at one end portion in the length direction of the steel plate 102, a portion from the other end portion in the width direction of the steel plate 102 to a direction 60 mm parallel to the width direction of the steel plate 102 is removed from the back surface of the steel plate 102. Cut to the end of the steel plate 102 in the longitudinal direction at a half portion in the plate thickness direction at an angle of 60 ° with respect to the back surface of the steel plate 102 (third step). Accordingly, the steel plate 102 is at an angle of 60 ° with respect to the direction parallel to the steel plate 102 from one surface in the length direction of the steel plate 102 to the distance t / 2 of the thickness of the steel plate 102 from the surface of the steel plate 102. Inclined to the outside of the steel plate 102, and inclined to the outside of the steel plate 102 at an angle of 60 ° with respect to the direction parallel to the steel plate 102 from the back surface of the steel plate 102 to a distance t / 2 of the plate thickness of the steel plate 102. . And in the width direction 80mm except 60mm from the both ends of the width direction of the steel plate 102, the part from the back surface to the distance of half the thickness t / 2 of the steel plate 102 is an angle of 60 ° with respect to the direction parallel to the steel plate 102. It protrudes to the outside of the steel plate 102. In addition, the number of manufacturing processes shall be counted continuously from the manufacturing process of this steel plate 102.

  Further, as shown in FIGS. 12C and 12D, the steel plate 103 has a width of 200 mm, a length of 75 mm, and a plate thickness t. First, one end portion in the length direction of the steel plate 103 is from the surface of the steel plate 103 to one end portion in the length direction of the steel plate 102 at a half portion in the plate thickness direction of the steel plate 102 with respect to the surface of the steel plate 103. Cutting at an angle of 60 ° (fourth step). Then, one end portion in the length direction of the steel plate 103 is from the back surface of the steel plate 103 to one end portion in the length direction of the steel plate 102 at a half portion in the plate thickness direction of the steel plate 102 with respect to the back surface of the steel plate 103. Cutting at an angle of 60 ° (fifth step). As a result, at one end portion in the length direction of the steel plate 103, from the surface of the steel plate 103 to a distance of t / 2 of the plate thickness of the steel plate 103, the outside of the steel plate 103 at an angle of 60 ° with respect to the direction parallel to the steel plate 103. From the back surface of the steel plate 103 to the distance t / 2 of the plate thickness of the steel plate 103, the steel plate 103 is inclined to the outside of the steel plate 103 at an angle of 60 ° with respect to the direction parallel to the steel plate 103. One end in the length direction of the steel plate 102 and one end in the length direction of the steel plate 103 are abutted, and a portion from the one end in the width direction of the steel plate 102 and the steel plate 103 to a direction parallel to the width direction of the steel plate is 60 mm. Is restrained and welded (sixth step), and the portion from the other end in the width direction of the steel plate 102 and the steel plate 103 to the direction 60 mm parallel to the width direction of the steel plate is restrained and welded (seventh step).

  Thus, in the prior art, the y-type weld crack test plate 101 is manufactured by seven processes. The test weld 104 has a y-shaped cross section as shown in FIG. 11B, which is a cross-sectional view taken along the line AA of FIG. Moreover, the restraint welding part 105 which restrainedly welded steel plates is as shown in FIG.11 (c) which is BB sectional drawing of Fig.11 (a). And at the time of restraint welding, as shown to Fig.13 (a), as shown in Fig.13 (a), the state which provided the copper-plating gold | metal | money 107 so that the sputter | spatter which generate | occur | produces by a restraint welding bead and restraint welding may not penetrate into a test-welding groove And restraint welding is performed. As shown in FIG. 13B, which is a cross-sectional view taken along the line AA of FIG. 13A, the copper abutment 107 is fitted on the upper surface side of the y-shaped cross section of the steel plate. Moreover, the part which restrained-welded steel plates is as shown in FIG.13 (c) which is BB sectional drawing of Fig.13 (a).

  Then, when the steel plates are subjected to restraint welding, as shown in FIG. 14, the spacer 106 is sandwiched between the weld start end portion and the weld end portion of the test weld portion 104, and the route gap 110 of the test weld portion 104 is set to a predetermined value. Adjust to g. The route gap 110 of the test weld 104 is described in JIS Z 3158 by selecting an appropriate value in the range of 1.0 mm to 2.0 mm, and the tolerance is ± 0.2 mm. However, the test plate 101 requires the spacer 106 for forming the root gap 110. Also, due to the shrinkage of the test welded portion 104 by restraint welding and the shape deformation of the spacer 106 by restraint welding, etc. It was difficult to form the root gap 110 stably.

  Therefore, in recent years, as shown in FIGS. 15A to 15F, a recess 114 is formed in advance in the steel plate 112, and the steel plate 112 and the steel plate 113 are restrained and welded to test the recess 114 as it is. A test plate is used to obtain a stable root gap so as to be a root gap of a weld.

  As shown in FIGS. 15A, 15B, and 15C, this steel plate 112 has a width of 200 mm, a length (75 + plate thickness t / 3.4) mm, and a plate thickness t of 50 mm. At one end in the length direction of the steel plate, the steel plate 112 is inclined to the outside of the steel plate 112 at an angle of 60 ° with respect to the direction parallel to the steel plate 112 from the surface of the steel plate 112 to a distance t / 2 of the plate thickness of the steel plate 112. From the back surface of 112 to a distance of half the thickness t / 2 of the steel plate 112, the steel plate 112 is inclined to the outside of the steel plate 112 at an angle of 60 ° with respect to the direction parallel to the steel plate 112. And in the width direction 80mm except 60mm from the both ends of the width direction of the steel plate 112, the part from the back surface to the distance of half t / 2 of the plate | board thickness of the steel plate 112 is an angle of 60 degrees with respect to the direction parallel to the steel plate 112. It protrudes to the outside of the steel plate 112. Further, in this protruding portion, a recess 114 having a depth of 1.5 mm is formed from the back surface to the top surface in a width direction of 72 mm excluding 64 mm from both ends of the steel plate 112 in the width direction.

  Further, as shown in FIGS. 15D, 15E, and 15F, the steel plate 113 has a width of 200 mm, a length of 75 mm, and a plate thickness t of 50 mm. At one end of the steel plate 113 in the length direction, From the upper surface of the steel plate 113 to the distance of half t / 2 of the plate thickness of the steel plate 113, the steel plate 113 is inclined to the outside of the steel plate 113 at an angle of 60 ° with respect to the direction parallel to the steel plate 113. Is inclined to the outside of the steel plate 113 at an angle of 60 ° with respect to the direction parallel to the steel plate 113 up to a distance of t / 2. By restraint welding the steel plate 112 and the steel plate 113, the recess 114 formed in the steel plate 112 becomes the root gap of the test weld as it is.

  Further, in Patent Document 1, in a y-type weld crack test piece used for a y-type weld crack test in non-molten electrode welding such as TIG welding, a groove is formed in a straight line at a central portion of the test piece. There is disclosed a y-type weld crack test piece in which a hole is provided along the longitudinal direction of the groove, and the hole communicates with the outside of the y-type weld crack test piece and the groove in a straight line. Then, a welding rod is inserted into the hole from the outside of the y-shaped weld crack test piece, the tip of the welding rod is associated with the electrode of TIG welding, test welding is started, and the welding rod and the electrode are moved simultaneously. Continue welding from one end of the groove to the other. As a result, this conventional technique can maintain the test bead over the entire length in the longitudinal direction of the groove even when performing non-molten electrode welding such as TIG welding with a y-shaped weld crack specimen having a relatively large groove depth. It is intended to be easily provided. In addition, the y-type weld crack test piece used for the y-type weld crack test in this prior art is produced by restraining welding of two steel plates.

  In Patent Document 2, in a weld crack test piece used for laser welding, two flat test pieces having convex portions are placed so that the convex portions face each other, and the convex portions are abutted to each other. A I-type weld crack test piece is held in which a gap setting block is fitted in the concave portions formed on both sides of the portion, a root gap is formed between the opposing convex portions, and two test pieces are pressed against the gap setting block. It is disclosed. This conventional technique adjusts the protrusion length of the protrusions and the length in the direction parallel to the protrusion direction of the protrusions of the test piece in the gap setting block, so that the route gap formed between the protrusions can be made with high accuracy. This is what you want to set.

JP-A-6-180278 JP 2011-36911 A

  However, since the conventional y-shaped weld crack test plate 111 shown in FIG. 15 needs to restrain and weld two steel plates, the accuracy of the route gap of the test weld is said to affect the weld crack test. There is a problem that it is difficult to secure.

  In the y-type weld crack test plate (FIGS. 11, 12, and 14) in which a root gap is formed by the spacer 106 as a factor affecting the gap accuracy, the material and shape of the spacer 106 can be cited. Welding conditions for restraint welding of the steel sheet, such as welding material, welding heat input, number of lamination passes, interpass temperature, front and back welding sequence, and the like can be mentioned. Further, as a factor affecting the gap accuracy, a y-type weld crack test plate 111 (FIG. 15) in which a recess 114 is formed in advance in the steel plate 112 and a root gap is formed by restraining welding of the steel plate 112 and the steel plate 113. In, the accuracy of machining performed to form the recess 114 is mentioned, and welding conditions when restraining welding of two steel plates, for example, welding material, welding heat input, number of lamination passes, temperature between passes, For example, the front and back welding order.

  Usually, in the y-type weld cracking test, the preheating temperature and the immediately following heat condition are often changed to determine the crack prevention temperature control condition. Therefore, in order to change the preheating temperature and the immediately following heat condition in each of the test plate materials, It is necessary to prepare a plurality of test plates for each type of test plate material. Therefore, even if the welding conditions are relatively appropriate, when machining and restraint welding are performed on multiple test plates, the machining accuracy may change for each test plate, and the degree of shrinkage due to welding changes. Even if the same material is used, the route gap 110 becomes too small as shown in FIG. 16 (a), or the route gap 110 becomes too large as shown in FIG. 16 (b). . In addition, when the welding conditions are not appropriate, the degree of angular deformation may vary from test plate to test plate when restraint welding is performed on a plurality of test plates. ), The root gap 121 immediately below the test weld bead is smaller than the root gap 122 in the vicinity of the back side of the steel plate, or the root just below the test weld bead as shown in FIG. The gap 121 may be larger than the root gap 122 in the vicinity of the back side of the steel plate.

  Factors affecting the occurrence of weld cracks in the y-type weld crack test are constraints that are indicative of the degree of restraint in relation to the hardness of the test weld, the amount of diffusible hydrogen in the test weld, and the thickness of the test plate. It is said that it is degree. However, in the y-type weld crack test, when these factors are changed in each test plate in order to examine the influence of these factors on the weld crack, the root gap of the test weld that is not these factors is tested. It must be formed uniformly for each plate. Therefore, as described above, if the root gap of the test weld varies for each y-type weld crack test plate, accurate evaluation cannot be performed in the y-type weld crack test.

  In order to increase the accuracy of the y-type weld crack test, in order to ensure the stable gap accuracy of the y-type weld crack test plate, until now, we have searched for the optimum conditions for machining and in the welding conditions for restraint welding, Search for optimum conditions such as welding materials, welding heat input, number of lamination passes, temperature between passes, and timing of front and back welding distribution, and create y-type weld crack test plates under these optimum conditions. The gap was formed with a predetermined accuracy.

  In addition, test welding in the y-type weld cracking test is normally completed in about 20 seconds, whereas restraint welding in which two steel plates are welded is, for example, 3 to 3 until completion when the steel plate has a thickness of 50 mm. It took 4 hours and required a lot of welding man-hours.

  In Patent Document 1, since two steel plates are restrained and welded in order to produce a y-shaped weld crack test piece, the accuracy of the root gap and the number of manufacturing steps are reduced when the two steel plates are restrained and welded. The problem of increase arises.

  Patent Document 2 discloses a method of forming a route gap of an I-shaped groove with high accuracy, and does not form a route gap of a test weld portion of a y-type weld crack test plate with high accuracy. .

  The present invention has been made in view of such problems, and it is possible to accurately form a root gap of a test weld portion of a y-type weld crack test plate, and to significantly reduce the number of manufacturing steps, and its An object is to provide a manufacturing method.

  The y-type weld crack test plate according to the present invention is formed so as to extend linearly in a region excluding the test plate main body made of steel and the edge of the surface of the main body, and is perpendicular to the linearly extending direction. A V-shaped groove having a V-shaped groove having a slope whose cross-section in the width direction intersects at an angle corresponding to the groove angle of the y-shaped groove to be tested, and extends from the entire bottom of the V-shaped groove to the back surface of the main body. Open on the back surface of the main body, one surface of which is inclined in the same plane as one inclined surface of the V-shaped groove, and the distance between the two opposing surfaces corresponds to the root gap of the y-shaped groove to be tested. And a flat slit.

  The method for producing a y-type weld crack test plate according to the present invention is such that the y-type weld crack test plate is inclined in a direction perpendicular to the surface of the main body in a plane perpendicular to the first direction parallel to the surface of the test plate main body made of steel. In the step of forming a linear hole penetrating from the front surface of the main body to the back surface, and in a region excluding the edge of the front surface of the main body, a flat plate-like shape is formed so as to extend from the linear hole in the first direction. A step of forming a hole, and at the upper part of the flat plate-like hole, the other inclined surface intersecting with one inclined surface of the upper part at an angle corresponding to the groove angle of the y-shaped groove to be tested is formed. A step of forming a V-shaped groove and a step of removing a burr generated when the V-shaped groove is formed, and a lower portion of the flat plate hole is a root gap of a y-shaped groove to be tested. A slit having a corresponding interval is formed.

  In this case, it is preferable that the linear hole, the flat hole, and the V-shaped groove are formed by wire electric discharge machining or machining.

  The manufacturing method of the y-type weld crack test plate according to the present invention is based on machining or electric discharge from one steel plate to the prior art in which the ends of two steel plates are machined and then butt-welded and restrained. Since it can be produced simply by processing the slopes of straight holes, flat holes, and V-shaped grooves by machining or the like, the number of production steps can be significantly reduced as compared with the prior art. Further, the present invention does not assemble two steel plates by welding in a state in which the root gap is defined by a spacer as in the prior art, but rather flat plate slits by machining or electric discharge machining or the like on one steel plate. Since the route gap is defined by the flat slit, the route gap of the test weld portion of the test plate can be formed with high accuracy, and the accuracy of the y-type weld crack test can be improved.

(A) is a top view which shows the y-type weld crack test plate which concerns on embodiment of this invention, (b) is sectional drawing which similarly shows the AA cross section of the test weld part of this y-type weld crack test plate, (C) is sectional drawing which shows the BB cross section of the part except the test welding part of this y-type weld crack test board similarly. (A) is a figure which shows forming a linear hole in a steel plate in the y-type weld crack test plate which concerns on embodiment of this invention, (b) is a cross section which similarly shows the AA cross section of this steel plate. FIG. (A) is a figure which shows forming a flat hole in a steel plate in the y-type weld crack test plate concerning the embodiment of the present invention, and (b) is a section showing an AA section of this steel plate similarly. FIG. (A) is a figure which shows forming a V-shaped groove | channel in a steel plate in the y-type weld crack test board which concerns on embodiment of this invention, (b) is sectional drawing which similarly shows the AA cross section of this steel plate. (C) is sectional drawing which similarly shows the BB cross section of this steel plate. (A) is a figure which shows the burr | flash produced when forming a V-shaped groove | channel in the y-type weld crack test board which concerns on embodiment of this invention, (b) is produced when forming this V-shaped groove | channel similarly. Sectional drawing which shows a burr | flash and shows the AA cross section of a steel plate, (c) is sectional drawing which shows the BB cross section of a steel plate in the y-type weld crack test plate which concerns on embodiment of this invention. (A), (b) is sectional drawing which shows removing a burr | flash with a cutter in the y-type weld crack test plate which concerns on embodiment of this invention. (A) is a top view which shows the state which test-welded to the y-type weld crack test plate which concerns on embodiment of this invention, (b) shows the AA cross section of this y-type weld crack test plate similarly. It is sectional drawing. (A) is a top view which shows the state which test-welded to the conventional y-type weld crack test plate, (b) is sectional drawing which similarly shows the AA cross section of this y-type weld crack test plate. It is a figure which shows the test weld bead direct lower part GU which is a root gap of the test weld part of a y-type weld crack test plate, and the back surface side vicinity part GL of a steel plate. It is a graph which shows the evaluation result of the Example of this invention. (A) is a plan view showing a conventional y-type weld crack test plate, (b) is a cross-sectional view showing an AA cross section of the test weld portion of the y-type weld crack test plate, and (c) is It is sectional drawing which similarly shows the BB cross section of the restraint welding part of this y-type weld crack test plate. (A) is a plan view showing a first steel plate constituting a conventional y-shaped weld crack test plate, (b) is a side view showing the same first steel plate, and (c) is a conventional y-shape. The top view which shows the 2nd steel plate which comprises a weld crack test board, (d) is a side view which shows this 2nd steel plate similarly. (A) is a top view which shows having provided the copper plating in the test weld part of the conventional y-type weld crack test plate, (b) is A- of the test weld part of this y-type weld crack test plate. Sectional drawing which shows A cross section, (c) is sectional drawing which similarly shows the BB cross section of the constrained welding part of this y-type weld crack test plate. It is a figure which shows having pinched | interposed the spacer in a test plate, in order to form the root gap of the conventional y-type weld crack test plate. (A) is a top view which shows the 1st steel plate which comprises the conventional y-type weld crack test plate which improved the route gap formation method, (b) is a front view which similarly shows this 1st steel plate, (c) ) Is a side view showing the same first steel plate, (d) is a plan view showing a second steel plate constituting a conventional y-type weld crack test plate with an improved route gap forming method, and (e) The front view which similarly shows this 2nd steel plate, (f) is a side view which similarly shows this 2nd steel plate. (A) is a figure which shows that the route gap of the test weld part of a y-type weld crack test plate became too small, (b) is a figure which shows that this route gap became excessive too. (A) is a diagram showing that the root gap immediately below the test weld bead of the y-type weld crack test plate is smaller than the root gap in the vicinity of the back surface side of the steel plate, and (b) is the same test weld bead. It is a figure which shows that the root gap of the direct lower part became larger than the root gap of the back surface side vicinity part of a steel plate.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. Fig.1 (a) is a top view which shows the y-type weld crack test plate which concerns on embodiment of this invention, FIG.1 (b) similarly shows the AA cross section of the test weld part of this y-type weld crack test plate. Sectional drawing shown and FIG.1 (c) are sectional drawings which show the BB cross section of the part except the test welding part of this y-type weld crack test plate similarly. As shown to Fig.1 (a), the y-type weld crack test plate 1 of this invention has the test plate main body 2 which consists of steel materials. For the test plate main body 2, for example, a steel plate having a thickness of 50 mm, a length of 150 mm, and a width of 200 mm of a welded steel plate SM490A is used as a test steel material. And the test welding part 9 is formed in the area | region except the edge part of the surface of this test plate main body 2. As shown in FIG. Thus, since this test weld 9 is formed in a region excluding the edge of the surface of the test plate main body 2, the test accuracy due to the influence of the welding position on the test plate main body 2 on the test results is obtained during the test welding. Can be avoided. Preferably, the test weld 9 is formed at the center of the test plate body 2. For example, the test welded portion 9 starts from one end in the width direction of the test plate main body 2 at a position 60 mm in a direction parallel to the width direction of the test plate main body 2 and starts from that position in the width direction of the test plate main body 2. The other end of the test plate 2 is linearly extended to a position of 80 mm in a direction parallel to the width direction of the test plate 2. Since the width of the test plate body 2 is 200 mm, the test plate welded portion 9 has both end portions at positions 60 mm in the direction parallel to the width direction of the test plate body 2 from both end portions in the width direction of the test plate body 2. The test plate body 2 has a length of 80 mm in a direction parallel to the width direction.

  FIG.1 (b) is sectional drawing of the test welding part 9 in a surface perpendicular | vertical to the direction where the test welding part 9 extends linearly. As shown in FIG. 1 (b), the test weld 9 has a V-shaped groove 6 at the upper part and a flat plate at the lower part in the cross section in the width direction perpendicular to the direction in which the test weld extends linearly. It is a slit 11. Since the V-shaped groove 6 constitutes the upper part of the test welded portion 9, the V-shaped groove 6 is formed in a region excluding the edge of the surface of the test plate main body 2, similarly to the test welded portion 9. For example, the V-shaped groove 6 starts from a position 60 mm in the direction extending linearly of the test weld 9 from one end in the width direction of the test plate main body 2, and starts from the position of the test plate main body 2. It is formed so as to extend linearly to the position of 80 mm in the direction of linear extension of the test weld 9 toward the other end in the width direction. Since the width of the test plate body 2 is 200 mm, the V-shaped groove 6 has both ends at 60 mm in the direction extending linearly from the both ends of the test plate body 2 in the width direction. The welded portion 9 has a length of 80 mm in the direction extending in a straight line. The V-shaped groove 6 is a slope in which the cross section in the width direction perpendicular to the direction in which the V-shaped groove 6 extends linearly intersects at an angle corresponding to the groove angle of the y-shaped groove of the y-shaped weld crack test object. The angle corresponding to the groove angle of the y-shaped groove of the y-type weld crack test object is, for example, 60 °. One inclined surface 6a and the other inclined surface 6b of the V-shaped groove 6 are inclined at an angle of 60 ° with respect to the surface of the test plate body 2, for example. The V-shaped groove 6 has, for example, a depth of 25 mm which is 1/2 of the thickness of the test plate body 2 in the thickness direction of the test plate body 2. The position of the test plate main body 2 in the plate thickness direction 25 mm from the surface of the plate main body 2 toward the back surface of the test plate main body 2 becomes the bottom of the V-shaped groove 6.

  And the flat slit 11 which comprises the lower part of the test welding part 9 is extended from the whole region of the bottom part of the V-shaped groove | channel 6 to the back surface of the test plate main body 2, and is opened in the back surface of the test plate main body 2. FIG. Thus, since the flat slit 11 extends from the entire bottom of the V-shaped groove 6 to the back surface of the test plate main body 2, the flat slit 11 is, for example, a V-shaped groove. 6 has a length of 80 mm in a direction extending linearly. And this flat slit 11 is formed from the back surface of the test plate main body 2 to the position of 25 mm in the plate | board thickness direction of the test plate main body 2 toward the surface direction of the test plate main body 2, for example. Further, one surface 11 a of the flat slit 11 is inclined, for example, at an angle of 60 ° with respect to the back surface of the test plate main body 2, and the one surface 11 a of the flat slit 11 is the V-shaped groove 6. It is inclined on the same plane as one of the slopes 6a. And the space | interval of two surfaces where the one surface 11a of this flat slit 11 and the other surface 11b oppose respond | corresponds to the root gap of the y-shaped groove of a y-type weld crack test object, The distance between the two surfaces where the one surface 11a and the other surface 11b of the slit 11 face each other is, for example, 1.0 to 2.0 mm.

  FIG.1 (c) is sectional drawing of the test plate main body 2 in which the test weld part 9 in the surface perpendicular | vertical to the direction where the test weld part 9 extends linearly is not formed. As shown in FIG. 1C, the portion of the test plate body 2 where the test weld 9 is not formed is not subjected to restraint welding.

  When restraint welding is performed, the root gap of the test weld 9 of the y-type weld crack test plate 1 varies due to variations in welding conditions. As a result of diligent investigation and trial production in order to accurately form the root gap of the test weld 9 of the y-type weld crack test plate 1 and reduce the number of manufacturing steps of the y-type weld crack test plate 1, one piece The present inventors have found a method for manufacturing an integrated y-type weld crack test plate that has a groove with good gap accuracy in the test plate body 2 and can significantly reduce the number of manufacturing steps compared to the prior art.

  The y-type weld crack test plate 1 according to the present invention is not subjected to two or more steel plates assembled by restraint welding in a state in which a root gap is defined by a spacer as in the prior art. The V-shaped groove 6 and the flat slit 11 are formed by electric discharge machining or the like, and the root gap is defined by the flat slit 11, so that the root gap of the test welded portion of the y-shaped weld crack test plate 1 is accurately formed. The accuracy of the y-type weld crack test can be increased.

  Next, the manufacturing method of the y-type weld crack test plate 1 of the present invention will be shown. FIG. 2 (a) is a diagram showing that a straight hole is formed in a steel plate in a y-type weld crack test plate according to an embodiment of the present invention, and FIG. 2 (b) is AA of this steel plate. FIG. 3A is a cross-sectional view showing a cross section, and FIG. 3A is a diagram showing that a plate-shaped hole is formed in a steel plate in a y-type weld crack test plate according to an embodiment of the present invention, and FIG. FIG. 4A is a cross-sectional view showing the AA cross section of the steel plate, and FIG. 4A is a view showing forming a V-shaped groove in the steel plate in the y-type weld crack test plate according to the embodiment of the present invention. 4 (b) is a cross-sectional view showing the AA cross section of the steel plate, FIG. 4 (c) is a cross-sectional view showing the BB cross section of the steel plate, and FIG. FIG. 5B is a view showing burrs generated when forming a V-shaped groove in the y-type weld crack test plate according to the embodiment of the present invention. FIG. 5C is a cross-sectional view showing the A-A cross section of the steel sheet, and FIG. 5C is a cross-sectional view of the y-type weld crack test plate according to the embodiment of the present invention. FIGS. 6A and 6B are cross-sectional views showing that burrs are removed with a blade in the y-type weld crack test plate according to the embodiment of the present invention.

  First, as shown in FIGS. 2 (a) and 2 (b), for example, a test plate which is a steel plate SM490A having a thickness of 50 mm, a length of 150 mm and a width of 200 mm, by a small diameter drilling or wire electric discharge machining. A straight hole penetrating from the front surface of the test plate body 2 to the back surface so as to be inclined with respect to the direction perpendicular to the surface of the test plate body 2 in a plane perpendicular to the first direction 10 parallel to the surface of the main body 2. 3 is formed (first step). The linear hole 3 has, for example, a diameter of φ1.0 to 2.0 mm, and from one end in the width direction of the test plate body 2 to a position 60 mm in a direction parallel to the first direction 10. It has an inclination angle of 30 ° with respect to the direction perpendicular to the surface of the test plate main body 2, that is, an inclination angle of 60 ° with respect to the surface of the test plate main body 2.

  Next, as shown in FIGS. 3A and 3B, in the region excluding the edge of the surface of the test plate body 2, for example, by wire electric discharge machining, from the linear hole 3 in the first direction 10. A flat hole 4 is formed so as to extend (second step). The flat hole 4 is parallel to the first direction 10 starting from the straight hole 3 at a position 60 mm parallel to the first direction 10 from one end in the width direction of the test plate body 2. Is processed until it returns to the linear hole 3 again. Thereby, the flat hole 4 has, for example, a length of 80 mm in the first direction 10 and a width perpendicular to the first direction of 1.0 to 2.0 mm which is the diameter of the linear hole 3. Similarly to the straight hole 3, it has an inclination angle of 60 ° with respect to the surface of the test plate main body 2.

  Then, as shown in FIGS. 4A, 4B, and 4C, for example, using a milling machine 5 or the like, y-type welding is performed on one inclined surface of the upper portion of the flat plate-like hole 4. The other inclined surface that intersects at an angle corresponding to the groove angle of the y-shaped groove to be cracked is formed to form the V-shaped groove 6 (third step). The V-shaped groove 6 is formed, for example, in the flat hole 4 from the surface of the test plate main body 2 to the back surface of the test plate main body 2 up to 25 mm in the plate thickness direction of the test plate main body 2. The depth of the V-shaped groove 6 is 25 mm. The milling machine 5 is perpendicular to the surface of the test plate main body 2 from the surface of the test plate main body 2 in the flat hole 4 in a state of being inclined by 30 ° from the direction perpendicular to the first direction 10 and perpendicular to the surface of the test plate main body 2. The tip of the milling machine 5 is directed to a portion having a distance of 25 mm in this direction, and cutting of the test plate body 2 is started from the surface of the test plate body 2. At that time, the milling machine 5 is moved from the position of the straight hole 3 which is one end in the width direction of the test plate body 2 in the flat hole 4, that is, from one end in the width direction of the test plate body 2. Cutting is performed from a position 60 mm in a direction parallel to one direction 10. And after the front-end | tip of the milling machine 5 reaches | attains the part of the plate | board thickness direction 25mm of the test plate main body 2 from the surface of the test plate main body 2 in the flat hole 4, the milling machine 5 is parallel to the 1st direction 10. The test plate main body 2 is cut while moving from one end of the test plate main body 2 in the width direction to a position of 140 mm starting from the position of 60 mm in the direction. As a result, the length of the V-shaped groove 6 in the first direction 10 is 80 mm, and the portion of the flat hole 4 from the surface of the test plate main body 2 to the distance of 25 mm in the plate thickness direction of the test plate main body 2 is one side. The angle formed by the one inclined surface and the other inclined surface is, for example, 60 °, and this angle corresponds to the groove angle of the y-shaped groove of the y-type weld crack test target. Moreover, the part of the distance of 25 mm in the plate | board thickness direction of the test plate main body 2 from the surface of the test plate main body 2 in the flat hole 4 shall be a bottom part (FIG.5 (c)). Moreover, the slit 13 which is a part from the lower part of the flat hole 4, for example, the distance of the plate | board thickness direction 25mm of the test plate main body 2 from the back surface of the test plate main body 2, is a y-shaped groove of a y-type weld crack test. There is an interval corresponding to the root gap of the groove, and this interval is the same as the width perpendicular to the first direction 10 of the flat hole 4, and is, for example, 1.0 to 2.0 mm.

  When forming the V-shaped groove 6, depending on the shape of the cutting tool such as the milling machine 5, as shown in FIGS. 5A and 5B, burrs 7 are formed at the bottom of both ends in the first direction 10 of the V-shaped groove 6. Occurs. As shown in FIGS. 6 (a) and 6 (b), the burr 7 is removed by molding automatically or manually using a dedicated blade 8 or a normal blade (fourth step).

  As described above, the integrated y-type weld crack test plate 1 shown in FIG. 1A is manufactured by four steps. As shown in FIG. 1B, which is a cross-sectional view taken along the line AA in FIG. 1A, the test welded portion 9 of the integrated y-type weld crack test plate 1 has a y-shaped cross section. Further, as shown in FIG. 1C, which is a BB cross-sectional view of FIG. 1A, the parts other than the test welded portion are not subjected to restraint welding as in the conventional test plate. As described above, the manufacturing method of the y-type weld crack test plate 1 according to the present invention is based on the above-described conventional technique in which the end portions of two steel plates are machined and then the two steel plates are brought into contact with each other to perform restraint welding. As described above, while seven steps are required, only the slope processing of the straight hole 3 and the flat hole 4 and the V-shaped groove 6 is performed from one steel plate by machining or electric discharge machining. Therefore, the number of manufacturing steps can be significantly reduced because the number of manufacturing steps is four compared to the seven steps of the prior art.

  In order to evaluate the accuracy of the root gap of the test weld 9 of the y-type weld crack test plate 1 of the present invention, the y-type weld crack test using the test plate 1 of the present invention and the conventional test plate 111 shown in FIG. The root gap after the evaluation was evaluated. Fig.7 (a) is a top view which shows the state which test-welded to the y-type weld crack test board which concerns on embodiment of this invention, FIG.7 (b) is A- of this y-type weld crack test board similarly. It is sectional drawing which shows A cross section, Fig.8 (a) is a top view which shows the state which test-welded to the conventional y-type weld crack test plate, FIG.8 (b) is also this y-type weld crack test. FIG. 9 is a cross-sectional view showing an AA cross section of a plate, and FIG. 9 is a view showing a test weld bead direct lower portion GU that is a root gap of a test weld portion of a y-type weld crack test plate and a rear surface side vicinity portion GL of the steel plate. is there. FIG. 7A shows a state in which test welding is performed on the test plate 1 of the present invention. As shown in FIG. 7A, the test weld 9 is divided into five in the welding direction, and the test piece 1, test piece 2, test piece 3, test piece 4, and test piece 5 are formed from the weld end, respectively. FIG. 7B is a cross-sectional view taken along the line AA in the test piece 5. FIG. 8A shows a state in which test welding is performed on the conventional test plate 111 shown in FIG. As shown in FIG. 8 (a), the test weld is divided into five in the welding direction, and the test piece 1, test piece 2, test piece 3, test piece 4, and test piece 5 are formed from the weld end, respectively. FIG. 8B is an AA cross-sectional view of the test piece 5.

  The cross-sectional macro test piece (test piece 3 in FIG. 7) at the center of the weld after performing the y-type weld cracking test using the test plate 1 of the present invention, and the conventional test plate 111 shown in FIG. As shown in FIG. 9, the cross-sectional macro test piece (test piece 3 in FIG. 8) after the y-type weld cracking test was performed, as shown in FIG. The root gap was measured. At this time, the root gap of the cross-sectional macro test piece was measured using a digital stereo projector. In addition, the target gap at the time of preparing the y-type weld crack test plate is the test number. No. 1 is 1.2 mm for both the test plate 1 of the present invention and the conventional test plate 111. 2 was 1.4 mm for both the test plate 1 of the present invention and the conventional test plate 111. And as shown in Table 1, the test No. 1, each of four test plates 1 of the present invention and four conventional test plates 111, test No. 1. 2, GU and GL were measured for four test plates 1 of the present invention and four conventional test plates 111, respectively, and the absolute value of the difference between GU and GL was determined. As described above, the present embodiment measures GU and GL, evaluates how much they vary with respect to the target gap, obtains the difference between GU and GL, and determines how much GU and GL are. Evaluation was made on whether or not they were different, and these were compared between the test plate 1 of the present invention and the conventional test plate 111 to evaluate the accuracy of the route gap of the test weld 9 of the y-type weld crack test plate 1 of the present invention.

  FIG. 10 is a graph showing the evaluation results of the example of the present invention. Table 1 and FIG. 1 and test no. 2 shows a route gap measurement result.

  Test No. 1, of the root gap of the test plate 111 according to the conventional method, the GU just below the test bead is the test plate No. 1. 1: 1.02 mm, test plate No. 2: 0.98 mm, test plate No. 3: 1.05 mm, test plate No. 4: 1.12 mm, which are 0.08 mm or more narrower than the target gap of 1.2 mm. And test no. In the case of No. 1, the difference between the GU just below the test bead GU of the route gap of the test plate 111 by the conventional method and the back surface side vicinity GL of the steel plate is the test plate No. 1. 1: 0.16 mm, test plate No. 2: 0.18 mm, test plate No. 3: 0.17 mm, test plate No. 4: 0.16 mm, and the difference between GU and GL varies by 0.16 mm or more.

  In contrast, test no. 1, of the route gap of the test plate 1 according to the present invention, the GU just below the test bead is the test plate No. 1. 1: 1.21 mm, test plate no. 2: 1.20 mm, test plate No. 3: 1.22 mm, test plate No. 4: 1.20 mm, which is limited to a range of +0.02 mm or less with respect to the target gap of 1.2 mm, and there is almost no variation for each test plate, and according to the conventional method described above. It is closer to the target gap than the GU of the test plate. And test no. In the case of No. 1, the difference between the GU just below the test bead GU of the root gap of the test plate 1 according to the present invention and the back surface side vicinity GL of the steel plate is the test plate No. 1: 0.01 mm, test plate no. 2: 0 mm, test plate No. 3: 0.01 mm, test plate No. 4: 0.02 mm, the difference between GU and GL is suppressed to 0.02 mm or less, and there is almost no variation between GU and GL, and GU and GL of the test plate according to the conventional method described above Less than the difference.

  Next, test no. 2, of the root gap of the test plate 111 according to the conventional method, the GU just below the test bead is the test plate No. 1: 1.32 mm, test plate no. 2: 1.36 mm, test plate No. 3: 1.43 mm, test plate No. 4: 1.45 mm, and the maximum value is 1.45 mm and +0.05 mm, and the minimum value is 1.32 mm and −0.08 mm with respect to the target gap of 1.4 mm. In addition, Test No. 2, among the root gaps of the test plate 111 according to the conventional method, the back surface side vicinity portion GL of the steel plate is the test plate No. 1: 1.18 mm, test plate no. 2: 1.21 mm, test plate No. 3: 1.28 mm, test plate no. 4: 1.24 mm, which are 0.12 mm or more narrower than the target gap of 1.4 mm. And test no. In the case of No. 2, the difference between the GU just below the test bead GU of the root gap of the test plate 111 by the conventional method and the back surface side vicinity GL of the steel plate is the test plate No. 2. 1: 0.14 mm, test plate No. 2: 0.15 mm, test plate No. 3: 0.15 mm, test plate No. 4: 0.21 mm, and the difference between GU and GL varies by 0.14 mm or more.

  In contrast, test no. 2, of the root gap of the test plate 1 according to the present invention, the GU just below the test bead is the test plate No. 1: 1.41 mm, test plate No. 2: 1.40 mm, test plate No. 3: 1.43 mm, test plate No. 4: 1.41 mm, which is suppressed to a range of +0.03 mm or less with respect to the target gap of 1.4 mm, and there is almost no variation for each test plate, and according to the conventional method described above. It is closer to the target gap than the GU of the test plate. In addition, Test No. 2, among the root gaps of the test plate 1 according to the present invention, the rear surface side vicinity GL of the steel plate has the test plate No. 1: 1.40 mm, test plate no. 2: 1.42 mm, test plate No. 3: 1.42 mm, test plate No. 4: 1.42 mm, which is limited to a range of +0.02 mm or less with respect to the target gap of 1.4 mm, and there is almost no variation for each test plate, and according to the conventional method described above. It is closer to the target gap than the GL of the test plate. And test no. In the case of No. 2, the difference between the GU directly below the test bead GU of the root gap of the test plate 1 according to the present invention and the back surface side vicinity GL of the steel plate is the test plate no. 1: 0.01 mm, test plate no. 2: 0.02 mm, test plate No. 3: 0.01 mm, test plate No. 4: 0.01 mm, the difference between GU and GL is suppressed to 0.02 mm or less, and there is almost no variation between GU and GL, and GU and GL of the test plate according to the conventional method described above Less than the difference.

  As described above, the root gap of the test welded portion 9 of the y-type weld crack test plate 1 of the present invention is the portion immediately below the test bead GU and the vicinity of the back side of the steel plate when the target gap is 1.2 mm and 1.4 mm. GL shows little variation with respect to the target gap, and there is almost no difference between GU and GL. According to the present invention, the gap accuracy of the test weld 9 in the y-type weld crack test plate 1 can be made extremely high, so that the accuracy of the y-type weld crack test can be increased. Moreover, since the y-type weld crack test plate 1 according to the present invention is not subjected to restraint welding, the number of manufacturing steps can be greatly reduced.

1: y-type weld crack test plate, 2: test plate body, 3: straight hole, 4: flat hole, 5: milling machine, 6: V-shaped groove, 6a: slope, 6b: slope, 7: burr 8: Blade, 9: Test weld, 10: First direction, 11: Flat slit, 11a: Slope, 11b: Slope, 12: Test weld bead, 13: Slit, 101: Y-type weld crack test plate, 102: Steel plate, 103: Steel plate, 104: Test weld, 105: Restraint weld, 106: Spacer, 107: Copper alloy, 110: Root gap, 111: Y-shaped weld crack test plate, 112: Steel plate, 113: Steel plate, 114: recess, 121: root gap immediately below the test weld bead, 122: root gap in the vicinity of the back side of the steel plate

Claims (3)

A test plate body made of steel,
The cross section in the width direction perpendicular to the linearly extending direction is an angle corresponding to the groove angle of the y-shaped groove to be tested, formed in a region excluding the edge of the surface of the main body so as to extend linearly. A V-shaped groove that is V-shaped with intersecting slopes;
The V-shaped groove extends from the entire bottom of the V-shaped groove to the back surface of the main body and opens on the back surface of the main body. One surface of the V-shaped groove is inclined in the same plane as the one inclined surface of the V-shaped groove, A flat slit corresponding to the root gap of the y-shaped groove to be tested;
A y-type weld crack test plate characterized by comprising: A straight hole penetrating from the surface of the main body to the back surface is formed so as to incline in a direction perpendicular to the surface of the main body in a plane perpendicular to the first direction parallel to the surface of the test plate main body made of steel. And a process of
Forming a flat hole so as to extend from the straight hole in the first direction in a region excluding the edge of the surface of the main body;
In the upper part of the flat hole, a V-shaped groove is formed by forming the other inclined surface that intersects one inclined surface of the upper part at an angle corresponding to the groove angle of the y-shaped groove to be tested. Process,
Removing burrs generated when forming the V-shaped groove;
Have
A method for producing a y-type weld crack test plate, wherein a lower part of the flat plate-like hole constitutes a slit having an interval corresponding to a root gap of a y-type groove to be tested. 3. The method of manufacturing a y-type weld crack test plate according to claim 2, wherein the straight hole, the flat hole, and the V-shaped groove are formed by wire electric discharge machining or machining.

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