A preparation process of reinforced cold-drawing steel

Abstract

The application discloses a preparation process of reinforced cold-drawing type steel, which comprises a reinforced cold-drawing type steel body, characterized in that the upper surface of the reinforced cold-drawing type steel body is provided with a semicircular protrusion, the lower surface of the reinforced cold-drawing type steel body is provided with a semicircular groove matched with the upper surface, and slanting grooves are formed in the two end sidewalls of the reinforced cold-drawing type steel body. The driving motor drives the rotating rod to rotate and drive the upper and lower half gears to rotate, the steel head clamping frame moves back and forth under the cooperation of the rack, the steel head clamping frame is loosened to clamp the steel blank when retreating and clamps the steel blank when advancing, a uniform forward pulling force is generated on the steel blank, the steel blank is cold-drawn through the die head, the problem that the existing technology lacks the persistent pulling force provided to the steel, the internal stress of the steel is uneven, and the strength is unstable is solved, and the strength of the steel can be increased by ensuring that the force received by the steel through the two sides of the die head is steadily increased when the steel is cold-drawn.

Description

Technical Field

[0001] This invention belongs to the field of cold-drawn steel preparation and production technology, specifically relating to a preparation process for reinforced cold-drawn steel. Background Technology

[0002] Cold-drawn steel is a special type of steel product. The raw materials for cold-drawn steel are typically steel billets and slabs. Its production process involves a series of steps, including raw material preparation, pretreatment, drawing, forging, and grinding. In the pretreatment stage, the steel billets and slabs need to be heated to an appropriate temperature to facilitate subsequent processing. Cold drawing is the core step in the processing of cold-drawn steel and is crucial for controlling its mechanical properties. During cold drawing, the raw materials undergo multiple drawing and rolling operations to reshape them into the desired cold-drawn steel. Typically, the steel billets and slabs first undergo an initial drawing process to control their deformation rate between 15% and 25%, followed by a fine drawing to increase the deformation rate to around 70%. After cold drawing, the cold-drawn steel needs to be forged to further improve its mechanical properties. Forging makes the internal grains of the steel finer and more uniform, increasing its strength and toughness, while also improving its surface quality.

[0003] In the core step of steel processing, cold drawing, existing technologies involve passing the steel through the forming hole of a cold drawing die at room temperature to obtain the corresponding shape. However, when the existing device clamps different sized irregular steel billets, the screw that controls the position of the clamp needs to rotate many times to increase the distance between the two clamps. In the existing technology, a Chinese patent document with publication number CN214601070U and publication date of November 5, 2021, is proposed, which uses a quick-change method for the clamp die head. However, this method results in a lack of continuous tensile force on the steel, leading to uneven internal stress and unstable strength in the steel.

[0004] Therefore, we need a process to strengthen the preparation of cold-drawn steel to solve the problem of uneven internal stress and unstable strength caused by the lack of continuous tensile force on the steel in the existing technology. This process can increase the strength of the steel by ensuring that the steel is subjected to stable forces on both sides of the die during cold drawing. Summary of the Invention

[0005] The purpose of this application is to solve the problem that the lack of continuous tensile force applied to steel in the prior art leads to uneven internal stress and unstable strength in steel. In order to solve the above problems, this application provides a process for preparing reinforced cold-drawn steel, which can increase the strength of steel by ensuring that the force on both sides of the steel is stable when the steel passes through the die during cold drawing.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a reinforced cold-drawn steel profile, comprising a reinforced cold-drawn steel profile body, characterized in that: a semi-circular protrusion is provided on the upper surface of the reinforced cold-drawn steel profile body, a semi-circular groove adapted to the upper surface is provided on the lower surface of the reinforced cold-drawn steel profile body, oblique grooves are respectively provided on the side walls at both ends of the reinforced cold-drawn steel profile body, and mounting protrusions are provided at the connection of the oblique grooves.

[0007] A process for preparing reinforced cold-drawn steel includes the following steps:

[0008] Step 1: Select steel billets and perform pretreatment;

[0009] Step 2: The pre-treated steel billet is cold-drawn using a cold-drawing mold base mechanism to form a reinforced cold-drawn steel body;

[0010] Step 3: Forge, chamfer, and grind the reinforced cold-drawn steel body after cold drawing. Finally, beveled grooves are formed on the side walls at both ends of the reinforced cold-drawn steel body.

[0011] The cold-drawn model base mechanism includes a cold-drawn model base, on which a mold head is snapped and installed. A constant tension mechanism is provided at the front end of the cold-drawn model base mechanism. The constant tension mechanism includes a pull guide frame. A drive motor is fixedly installed at the upper and lower ends of the outer side wall of the pull guide frame. The two sets of drive motors rotate in opposite directions. A steel head clamping frame is slidably installed inside the pull guide frame.

[0012] Preferably, the upper surface of the cold-drawing mold base is provided with a mounting groove adapted to the mold head in the middle, a semi-circular pad is slidably mounted on the inner side wall of the mold head, and a sliding groove adapted to the semi-circular pad is provided on the inner side wall of the mold head.

[0013] Preferably, a quick-change bolt is provided on the outer side of the semi-circular pad, the quick-change bolt is rotatably mounted on one side wall of the die head, and the inner side wall of the semi-circular pad is threadedly connected to the outer surface of the quick-change bolt.

[0014] Preferably, the output shaft of the drive motor is fixedly mounted with a rotating rod, one end of the rotating rod is rotatably connected to the inner surface of the pull guide frame, and a half gear is fixedly mounted in the middle of the rotating rod.

[0015] Preferably, racks are fixedly installed on the upper and lower surfaces of the steel head clamping frame, and the surface of the rack meshes with the surface of the half gear.

[0016] Preferably, the inner upper and lower ends of the steel head clamping frame are symmetrically provided with double-headed telescopic rods, and a clamping pad is provided between the double-headed telescopic rods. The outer surface of the cylinder of the clamping pad is fixedly connected to the inner surface of the steel head clamping frame.

[0017] Preferably, step one further includes selecting and cutting a steel billet, heating the cut steel billet, performing surface shot peening during the heating process to remove iron oxides and oxide scale from the surface, and then cleaning, drying and cooling.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] After the steel billet is clamped at one end by the steel head clamping frame, the drive motor drives the rotating rod to rotate, which in turn drives the upper and lower half gears to rotate. Because the half gears are half teeth in opposite directions, the steel head clamping frame moves back and forth with the help of the rack. When it moves backward, the steel head clamping frame releases the clamping of the steel billet, and when it moves forward, it clamps the steel billet, generating a uniform forward pulling force on the steel billet, so that it can be cold drawn and formed through the die head. This solves the problem of uneven internal stress and unstable strength of steel caused by the lack of continuous tensile force provided to the steel in the existing technology. It can increase the strength of the steel by ensuring that the force on both sides of the steel is stable when the steel is cold drawn through the die head. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the reinforced cold-drawn steel body structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the reinforced cold-drawn steel body splicing structure of the present invention;

[0022] Figure 3 This is a schematic diagram of the cold drawing process of the reinforced cold-drawn steel body of the present invention;

[0023] Figure 4 This is a schematic diagram of the pull guide rail frame structure of the present invention;

[0024] Figure 5 This is a schematic cross-sectional view of the pull guide rail frame structure of the present invention;

[0025] Figure 6 This is a schematic diagram of the mold head structure of the present invention;

[0026] Figure 7 This is a schematic diagram of the quick-change die head structure of the present invention;

[0027] Figure 8 This is a schematic diagram showing the disassembly of the mold head structure of the present invention;

[0028] Figure 9 This is a schematic diagram of the feeding frame structure of the present invention;

[0029] Figure 10 This is a schematic diagram of the pressure constant mechanism of the present invention.

[0030] In the diagram: 1. Reinforced cold-drawn steel body; 11. Beveled groove; 12. Mounting protrusion; 2. Cold-drawn mold base mechanism; 21. Cold-drawn mold base; 22. Die head; 23. Semi-circular pad; 24. Quick-change bolt; 3. Constant tension mechanism; 31. Pulling guide rail frame; 32. Drive motor one; 33. Rotating rod; 34. Half gear; 35. Steel head clamping frame; 351. Double-headed telescopic rod; 352. Clamping pad; 36. Rack; 4. Die head fixing mechanism; 41. Telescopic rod; 42. Extrusion rod; 43. Die head fixing clamp; 5. Constant pressure mechanism; 51. Feeding frame; 52. Roll mounting frame; 53. Adjusting double-headed threaded rod; 54. Drive motor two; 55. Roll; 56. Roll drive motor; 57. Gear; 571. Inertial gear. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the present invention clear and complete, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some, not all, embodiments of the present invention, and are merely illustrative of the embodiments of the present invention. They are not intended to limit the embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] Please see Figures 1 to 2 The present invention provides a technical solution: a reinforced cold-drawn steel profile, comprising a reinforced cold-drawn steel profile body 1, the upper surface of the reinforced cold-drawn steel profile body 1 is provided with a semi-circular protrusion, the lower surface of the reinforced cold-drawn steel profile body 1 is provided with a semi-circular groove adapted to the upper surface, the two end side walls of the reinforced cold-drawn steel profile body 1 are respectively provided with oblique grooves 11, and the connection of the oblique grooves 11 is provided with mounting protrusions 12;

[0034] The semi-circular protrusion on the top of the reinforced cold-drawn steel body 1 increases the strength of the reinforced cold-drawn steel body 1, and the semi-circular groove at the bottom increases the stress area of ​​the reinforced cold-drawn steel body 1. At the same time, the inner arch shape makes it less prone to bending and deformation. The two end side walls of the reinforced cold-drawn steel body 1 are respectively provided with oblique grooves 11, which form a complete fitting groove when the reinforced cold-drawn steel body 1 is spliced. After being engaged by the mounting protrusions 12, it is fixed with bolts, making the splicing and fixing of the reinforced cold-drawn steel body 1 convenient without welding.

[0035] Example 2

[0036] Please see Figures 3 to 10 This invention provides a technical solution: a process for preparing reinforced cold-drawn steel, comprising the following steps:

[0037] Step 1: Select steel billets and perform pretreatment;

[0038] Step 2: The pretreated steel billet is cold-drawn using the cold-drawing mold base mechanism 2 to form the reinforced cold-drawn steel body 1;

[0039] Step 3: Forge, chamfer and grind the cold-drawn reinforced cold-drawn steel body 1, and finally bevel grooves 11 are formed by beveling on both ends of the sidewalls of the reinforced cold-drawn steel body 1.

[0040] Step one also includes selecting and cutting steel billets, heating the cut steel billets, performing surface shot peening during the heating process to remove iron oxides and oxide scale from the surface, and then cleaning, drying and cooling.

[0041] The cold-drawing model holder mechanism 2 includes a cold-drawing model holder 21, with a mold head 22 snapped onto the top of the cold-drawing model holder 21. A constant tension mechanism 3 is provided at the front end of the cold-drawing model holder mechanism 2. The constant tension mechanism 3 includes a pull guide frame 31, with drive motors 32 fixedly mounted on the upper and lower ends of the outer side wall of the pull guide frame 31, respectively. The two sets of drive motors 32 rotate in opposite directions. A steel head clamping frame 35 is slidably installed inside the pull guide frame 31, and rotating rods are fixedly mounted on the output shafts of the drive motors 32. 33. One end of the rotating rod 33 is rotatably connected to the inner surface of the pull guide frame 31. A half gear 34 is fixedly installed in the middle of the rotating rod 33. A rack 36 is fixedly installed on the upper and lower surfaces of the steel head clamping frame 35 respectively. The surface of the rack 36 meshes with the surface of the half gear 34. Double-headed telescopic rods 351 are symmetrically arranged at the upper and lower ends of the inner side of the steel head clamping frame 35. A clamping pad 352 is arranged between the double-headed telescopic rods 351. The outer surface of the cylinder of the clamping pad 352 is fixedly connected to the inner surface of the steel head clamping frame 35.

[0042] The extension and retraction of the double-headed telescopic rod 351 allows the clamping pad 352 to clamp and loosen the steel billet. After clamping one end of the steel billet with the clamping pad 352, the drive motor 32 drives the rotating rod 33 to rotate, which in turn drives the upper and lower half gears 34 to rotate. Because the half gears 34 are half teeth with opposite directions, the steel head clamping frame 35 moves back and forth with the cooperation of the rack 36. When retracting, the double-headed telescopic rod 351 extends to control the clamping pad 352 to loosen its grip on the steel billet. When moving forward, the double-headed telescopic rod 351 retracts to control the clamping pad 352 to clamp the steel billet. As the steel head clamping frame 35 moves forward, it generates a uniform forward pulling force on the steel billet, causing it to be cold-drawn and formed through the die head 22. This solves the problem of uneven internal stress and unstable strength in steel caused by the lack of continuous pulling force provided to the steel in the existing technology. It can increase the strength of the steel by ensuring that the steel is subjected to stable forces on both sides of the die head when cold-drawing the steel.

[0043] Example 3

[0044] Based on Example 2: To ensure that the billet is not subjected to excessive or uneven extrusion pressure as it enters the die, this example adds a pressure-constant mechanism 5 to the rear end of the cold drawing die holder mechanism 2. The pressure-constant mechanism 5 includes a feeding frame 51, with a roll mounting frame 52 symmetrically slidably mounted on the inner side of the feeding frame 51. An adjusting double-ended threaded rod 53 is rotatably mounted on one side of the inner wall of the feeding frame 51. A second drive motor 54 is fixedly mounted on one side of the top of the feeding frame 51. The output shaft of the second drive motor 54 is fixedly connected to the upper end of the adjusting double-ended threaded rod 53. The wall is threadedly connected to the outer surface of the adjusting double-headed threaded rod 53. A roll 55 is rotatably mounted on the inner side of the roll mounting frame 52. The roll 55 is provided with multiple sets of diameters evenly arranged from small to large. A roll drive motor 56 is fixedly mounted on the outer side of the roll mounting frame 52. The output shaft of the roll drive motor 56 is fixedly connected to one end of the roll 55. Gears 57 are fixedly mounted on both sides of the roll 55. An inert gear 571 is provided between the gears 57. The inert gear 571 is rotatably mounted on the inner wall of the roll mounting frame 52. The outer surface of the gear 57 meshes with the outer surface of the inert gear 571.

[0045] By starting the drive motor 54, the double-headed threaded rod 53 is rotated, and the height of the roll mounting frame 52 is adjusted so that the height between the rolls 55 is the same as the height of the die head 22. The roll 55 closest to the die head 22 has the largest diameter. The change in the diameter of the roll 55 causes the steel billet to be squeezed and rolled under stable pressure. The roll drive motor 56 drives the outer rolls 55 to rotate. Because the inertial gear 571 and gear 57 mesh and rotate, the rolls 55 all rotate in the same direction, which pushes the steel billet so that the steel billet passes evenly through the die head 22 and is cold-drawn by the constant tension mechanism 3. This further solves the problem of uneven internal stress and unstable strength of steel caused by the lack of continuous tension in the existing technology. It can increase the strength of steel by ensuring that the steel is subjected to stable forces on both sides of the die head when cold-drawing steel.

[0046] Example 4

[0047] Based on Embodiment 2: In order to make the die head 22 applicable to the secondary cold drawing of steel billets without the need to replace the die head 22, this embodiment proposes that the upper surface of the cold drawing mold base 21 is provided with an installation groove adapted to the die head 22, a semi-circular pad 23 is slidably installed on the inner side wall of the die head 22, a sliding groove adapted to the semi-circular pad 23 is provided on the inner side wall of the die head 22, a quick-change bolt 24 is provided on the outer side of the semi-circular pad 23, the quick-change bolt 24 is rotatably installed on one side wall of the die head 22, and the inner side wall of one side of the semi-circular pad 23 is threadedly connected to the outer surface of the quick-change bolt 24;

[0048] During the initial cold drawing of the steel billet, the semi-circular pad 23 is located at the top of the inner wall of the die head 22, so that the steel billet is shaped into a regular shape by the die head 22. During the secondary cold drawing of the steel billet, the semi-circular pad 23 is moved to the bottom of the inner wall of the die head 22 by rotating the quick-change bolt 24, so as to realize the rapid deformation of the die head 22 and form a special shape of the steel billet with a convex upper part and a concave lower part, which increases the strength of the steel. This further solves the problem that the lack of continuous tensile force provided to the steel in the existing technology leads to uneven internal stress and unstable strength of the steel. It can increase the strength of the steel by ensuring the stability of the force on both sides of the die head when the steel is cold drawn.

[0049] Example 5

[0050] Based on Embodiment 4: In order to achieve stable support and quick replacement of the die head 22, this embodiment adds a die head fixing mechanism 4 to the outside of the die head 22. The die head fixing mechanism 4 includes a telescopic rod 41 hinged to both sides above the cold drawing model base 21. An extrusion rod 42 is rotatably installed at the output end of the telescopic rod 41. A die head fixing clamp 43 is hinged to one end of the extrusion rod 42. The inner surface of the die head fixing clamp 43 engages with the outer surface of the die head 22. A slide rail adapted to the die head fixing clamp 43 is provided on the upper surface of the cold drawing model base 21.

[0051] The extension of the telescopic rod 41 can push the extrusion rod 42 to cause the die head fixing plate 43 to press and fix the two sides of the die head 22, increasing the stability of the die head 22. The retraction of the telescopic rod 41 can pull the extrusion rod 42 to allow the die head fixing plate 43 to slide with the help of the slide rail, thus removing the fixation on the two sides of the die head 22. This makes it easier to disassemble and replace the die head 22, enabling quick replacement of the die head 22. This further solves the problem of uneven internal stress and unstable strength in steel caused by the lack of continuous tensile force provided to the steel in the existing technology. It can increase the strength of the steel by ensuring the stability of the force on both sides of the die head when the steel is cold drawn.

[0052] Example 6

[0053] Based on Example 5, a specific method for strengthening the cold drawing of cold-drawn steel is proposed, including the following steps:

[0054] Step 1: The pre-treated steel billet is transported to the loading frame 51. The drive motor 54 is started to drive the adjusting double-headed threaded rod 53 to rotate. The height of the roll mounting frame 52 is adjusted so that the height between the rolls 55 is the same as the height of the die head 22. At this time, the semi-circular pad 23 is located at the top of the inner wall of the die head 22. The roll drive motor 56 drives the outer rolls 55 to rotate. The inertial gear 571 meshes with the gear 57 and rotates so that the rolls 55 rotate in the same direction, which pushes the steel billet so that the steel billet passes through the die head 22 evenly.

[0055] Step two: The extension and retraction of the double-headed telescopic rod 351 allows the clamping pad 352 to clamp and fix one end of the steel billet and then release it. After the clamping pad 352 clamps one end of the steel billet, the drive motor 32 drives the rotating rod 33 to rotate, which in turn drives the upper and lower half gears 34 to rotate. Because the half gears 34 are half teeth with opposite directions, the steel head clamping frame 35 moves back and forth with the cooperation of the rack 36. When retracting, the double-headed telescopic rod 351 extends to control the clamping pad 352 to release the clamping of the steel billet. When moving forward, the double-headed telescopic rod 351 retracts to control the clamping pad 352 to clamp the steel billet. As the steel head clamping frame 35 moves forward, it generates a uniform forward pulling force on the steel billet, allowing it to undergo initial cold drawing and forming through the die head 22.

[0056] Step 3: Rotate the quick-change bolt 24 to move the semi-circular pad 23 to the bottom of the inner wall of the die head 22, so as to realize the rapid deformation of the die head 22 and form a special shape of the billet with a convex upper part and a concave lower part. Then start the drive motor 2 54 to drive the adjustment double-headed threaded rod 53 to rotate, and adjust the height of the roll mounting frame 52 again so that the height between the rolls 55 is the same as the height of the die head 22.

[0057] Step four: The billet is repeatedly fed into the feeding frame 51 so that it is pressed and pushed through the die head 22 and subjected to secondary cold drawing by the constant tension mechanism 3.

[0058] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A process for preparing reinforced cold-drawn steel, wherein the reinforced cold-drawn steel includes a reinforced cold-drawn steel body (1), the upper surface of the reinforced cold-drawn steel body (1) is provided with a semi-circular protrusion, the lower surface of the reinforced cold-drawn steel body (1) is provided with a semi-circular groove adapted to the upper surface, and oblique grooves (11) are respectively opened on the side walls at both ends of the reinforced cold-drawn steel body (1), and mounting protrusions (12) are provided at the connection of the oblique grooves (11), characterized in that: Includes the following steps: Step 1: Select steel billets and perform pretreatment; Step 2: The pre-treated steel billet is cold-drawn using a cold-drawing mold base mechanism (2) to form a reinforced cold-drawn steel body (1). Step 3: Forging, chamfering and grinding are performed on the reinforced cold-drawn steel body (1) after cold drawing. Finally, oblique grooves (11) are formed on the side walls at both ends of the reinforced cold-drawn steel body (1). The cold drawing model base mechanism (2) includes a cold drawing model base (21), a mold head (22) is snapped onto the top of the cold drawing model base (21), and a constant tension mechanism (3) is provided at the front end of the cold drawing model base mechanism (2). The upper surface of the cold drawing mold base (21) is provided with a mounting groove that matches the mold head (22). A semi-circular pad (23) is slidably mounted on the inner side wall of the mold head (22). A sliding groove that matches the semi-circular pad (23) is provided on the inner side wall of the mold head (22). A quick-change bolt (24) is provided on the outer side of the semi-circular pad (23). The quick-change bolt (24) is rotatably mounted on one side wall of the mold head (22). A mold head fixing mechanism (4) is added to the outer side of the mold head (22). The mold head fixing mechanism (4) includes a telescopic rod (41) hinged to both sides above the cold drawing mold base (21). An extrusion rod is rotatably mounted on the output end of the telescopic rod (41). The rod (42) is hinged to one end of the extrusion rod (42) and a die head fixing plate (43) is installed. The inner surface of the die head fixing plate (43) engages with the outer surface of the die head (22). The upper surface of the cold drawing mold base (21) is provided with a slide rail that is compatible with the die head fixing plate (43). During the initial cold drawing of the steel billet, the semi-circular pad (23) is located at the top of the inner wall of the die head (22), so that the steel billet is shaped into a regular shape by the die head (22). During the secondary cold drawing of the steel billet, the semi-circular pad (23) is moved to the bottom of the inner wall of the die head (22) by rotating the quick-change bolt (24), so that the die head (22) can be quickly deformed to form a special shape of the steel billet with a convex upper part and a concave lower part. The constant tension mechanism (3) includes a pull guide frame (31). The upper and lower ends of the outer side wall of the pull guide frame (31) are respectively fixedly installed with drive motors (32). The two sets of drive motors (32) rotate in opposite directions. A steel head clamping frame (35) is slidably installed inside the pull guide frame (31).

2. The manufacturing process of a reinforced cold-drawn steel section according to claim 1, characterized in that: The inner wall of one side of the semi-circular pad (23) is threaded to the outer surface of the quick-change bolt (24).

3. The preparation process of a reinforced cold-drawn steel section according to claim 1, characterized in that: The output shaft of the drive motor (32) is fixedly mounted with a rotating rod (33). One end of the rotating rod (33) is rotatably connected to the inner surface of the pull guide frame (31). A half gear (34) is fixedly mounted in the middle of the rotating rod (33).

4. The manufacturing process of a reinforced cold-drawn steel section according to claim 3, characterized in that: The upper and lower surfaces of the steel head clamping frame (35) are respectively fixedly installed with racks (36), and the surface of the racks (36) meshes with the surface of the half gears (34).

5. The preparation process of a reinforced cold-drawn steel section according to claim 4, characterized in that: The inner upper and lower ends of the steel head clamping frame (35) are symmetrically provided with double-headed telescopic rods (351), and a clamping pad (352) is provided between the double-headed telescopic rods (351). The outer surface of the cylinder of the clamping pad (352) is fixedly connected to the inner surface of the steel head clamping frame (35).

6. The preparation process of a reinforced cold-drawn steel according to claim 1, characterized in that: Step one also includes selecting and cutting steel billets, heating the cut steel billets, performing surface shot peening during the heating process to remove iron oxides and oxide scale from the surface, and then cleaning, drying and cooling.

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