JPH0677695B2 - Hardening method for split liner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of hardfacing a wear-resistant split liner arranged in a ring shape such as a vertical grinding mill.

[Prior Art] Referring to FIG. 2, a vertical grinding mill 1 will be briefly described. A raw material to be ground is charged and supplied from a top portion 2 of the mill 1 through a pipe 3 to rotate a grinding table directly below the pipe 3. 4 fall on.

On the table 4, a plurality of large-diameter tire type special steel crushing rollers 6 made of special steel are pressed and supported by a mill casing 5 which is obliquely supported and rotates together with the table 4 by a frictional force with the table 4. .

The raw material to be crushed put on the table 4 is crushed by the crushing roller 6
It is crushed by the shearing force between the table 4 and the table 4, raised by the primary air supplied from below the mill casing 5, passed through the coarse powder separator 7, and discharged from the outlet 8.

The upper surface portion of the crushing table 4 that is in contact with the crushing roller 6 is heavily worn, so that the crushing table 4 has a better wear resistance than the base material in order to enable the crushing table 4 to be used for a long period of time. A ring-shaped table liner that is made of chromium-molybdenum alloy and is hardened and welded to the circumference.
Is provided.

Even if the ring-shaped table liner 9 is manufactured in a factory, it is dimensionally impossible to bring the ring-shaped table liner 9 into the mill 1 as it is. The divided piece 10 was manufactured in an arc shape as shown in FIG. 3, and was arranged and attached in a ring shape on the crushing table 4.

However, when the hardened overlay welded divided pieces 10 are attached to the grinding table 4 in a ring shape, the adjacent divided pieces 10 are
As shown in FIGS. 4 and 5, a slight gap 11 is generated between the crushing table 4 and the crushing roller 6, so that the crushing roller 6 rotates at the corner of the hard facing portion 12 facing the gap 11 while the crushing table 4 and the crushing roller 6 rotate. There has been a problem that when the surface hits and an impact is applied, a corner of the hardfacing portion 12 is missing, so-called edge chipping occurs.

Therefore, a plurality of divided pieces 10 constituting the ring-shaped table liner 9 are arranged in a ring shape, and the gaps between the divided pieces 10 are arranged.
A gap plate 13 having substantially the same height as that of the divided pieces 10 is inserted into each of the divided pieces 10, and the surfaces of the divided pieces 10 together with the divided pieces 13 are subjected to hardfacing welding (Fig. 5 (a)), and then the gap 11 is formed. Hardened part of the part 12
By removing the crevice plate 13 and the gap plate 13, each of the divided pieces 10 hardened by overlay welding is manufactured (Fig. 5 (b)), and the divided pieces 10 are attached on the crushing table 4 in a ring shape. Insert a gap plate 13 'having a height lower than that of the divided piece 10 into the gap 11 of
The divided piece 10 and the gap plate 13 'are fixed by welding,
A method of performing hardfacing welding at the same height as the hardfacing portion 12 of the divided piece 10 on the upper part of 13 'was adopted (Fig. 5 (c)).

[Problems to be Solved by the Invention] However, in the above-described conventional method, when the divided pieces 10 and the gap plate 13 'are welded using a welding rod having toughness, the surroundings are heated because the gap 11 is small. In the deposited metal,
The hardfacing metal that has been previously welded to the divided pieces 10 may be mixed in, and due to the fact that the welding amount is small, the divided pieces 10 are not sufficiently fixed to each other, and It had a defect that it cracked and chipped.

Further, since the gap 11 is narrow, there is a problem that it is difficult to perform the final hardfacing operation and a welding defect is likely to occur.

The present invention has been devised in view of the above problems of the prior art, forming a notch at the opposite end of each divided piece, and by welding the notch with a welding rod having toughness, hardening An object of the present invention is to provide a method for hardening and building up a divided liner, which can prevent the mixing of the overlay metal and firmly integrate the divided pieces, and which facilitates the welding work.

[Means for Solving the Problems] The present invention arranges a plurality of divided pieces constituting a ring-shaped table liner in a vertical grinding mill or the like in a ring shape, and radially divides the divided pieces into upper surfaces at opposite ends thereof. After forming a notch having a required width extending to the opposite side and inserting a closing plate between the notches facing each other to close the gap between the divided pieces, the surface of each divided piece is surrounded by the circumference with the closing plate. After the hardfacing welding is performed over the entire circumference in the direction, the hardfacing and the closing plate on the upper part of the closing plate are removed to produce the respective hardfacing welded divided pieces, and then the divided pieces are placed on the table. It is attached in a ring shape at a determined position, and a flat plate-like gap plate is vertically inserted into the gap between the divided pieces, and the upper part and the cutout part of the gap plate are the same as the hardfacing part bottom part of the divided piece. Weld up to the height with a tough welding rod to separate each segment and the gap plate. The present invention relates to a method for hardening overlay of a divided liner, characterized by performing hardening overlay welding on the upper portion of the welded portion at the same height as the hardening overlay of the divided piece.

[Operation] Since the cutout is formed at the end of the divided piece, the metal hardened on the upper surface of the divided piece does not mix into the weld metal during welding for integrating the divided piece. And because a large amount of welding can be secured, the welded part is firmly welded,
Further, the notch portion widens the welding space to facilitate the welding work.

EXAMPLES Examples of the present invention will be described below with reference to the drawings.

FIGS. 1 (a) to (f) show an embodiment of the present invention, in which the parts denoted by the same reference numerals as in FIGS. 3 to 5 (a), (b) and (c) are the same. It represents.

An embodiment of the present invention will be described with reference to FIGS. 1 (a) to 1 (f). In a factory, a plurality of ring-shaped table liners 9 are formed with a required gap 11 between them. As shown in FIG. 1 (a), a notch portion 14 having a required width 1 (for example, about 20 to 50 mm) is formed on the upper surface of each opposing end portion of the divided piece 10.
Is formed in the radial direction, and a width dimension for forming a gap 11 between the split pieces 10 is provided between the cutout portions 14 of the split pieces 10 arranged in a ring shape, as shown in FIG. The closed plate 15 is inserted, and the surface of each divided piece 10 together with the closed plate 15 is hardened by hardfacing welding in a circumferential direction with a material having good wear resistance, for example, a chromium molybdenum alloy material. A built-up portion 12 is formed.

Then, as shown in FIG. 1C, the closing plate 15 and the hardened overlay 12 on the upper side of the closing plate 15 are removed. At this time, the groove-shaped portion 17 is formed by obliquely removing the upper surface of the hardfacing portion 12 so as to have a width L (for example, 50 to 100 mm) larger than the width of the cutout portion 14. As described above, the hardfacing welded divided piece 10 is manufactured.

Next, each of the divided pieces 10 is attached in a ring shape at a predetermined position on the crushing table 4, and as shown in FIG. Is vertically inserted to the height of the bottom of the notch 14.

Next, as shown in FIG. 1 (e), the upper portion of the gap plate 13 ″ and the notch portion 14 are formed with a welding rod having toughness up to the same height as the bottom portion of the hardfacing portion 12 of the divided piece 10. Welding is performed, and the divided pieces 10 are fixed to each other by the welded portion 16.

Next, as shown in FIG. 1 (f), a hardfacing welding is applied to the groove-shaped portion 17 above the welding portion 16 at the same height as that of the hardfacing portion 12 of the divided piece 10. In this way, a ring-shaped table liner 9 is formed which is hardened by overlay welding and has no gap in the circumferential direction.

As described above, the notch portion 14 is provided at the end of each divided piece 10, and the notch portion 14 is welded with a welding rod having toughness as shown in FIG. Then, the increased welding amount allows the divided pieces 10 to be more firmly integrated. Further, by forming the groove-shaped portion 17 and the notch portion 14 as described above, the welding space is widened, the welding work is facilitated, and the hardfacing metal is not mixed into the weld metal at the time of welding. The welding of the pieces 10 is strengthened.

It should be noted that the hardfacing welding method for the divided liner of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

[Effects of the Invention] As described above, according to the method for overlay welding of split liners of the present invention, various excellent hardenings as described below can be achieved.

(1) Since the divided pieces are provided with notches and the notches are welded to integrate the divided pieces, the welding amount is increased and the divided pieces are made stronger than in the past. Can be integrated into.

(2) The formation of the cutout portion widens the welding space, which facilitates the welding work.

(3) By forming the notch, it is possible to work so that the hardfacing metal is not mixed into the weld metal when welding the divided pieces, and the welding strength of the divided pieces can be further improved.

[Brief description of drawings]

1 (a) to 1 (f) are partial cross-sectional views showing the work procedure of one embodiment of the present invention, FIG. 2 is a cross-sectional view of a vertical grinding mill, and FIG. Fig. 4 is a plan view in which are arranged in a ring shape, Fig. 4 is a view in the direction of IV-IV in Fig. 3, and Fig. 5 (a).
(B) and (C) are partial cross-sectional views showing a conventional hardening overlay method. 1 is a vertical grinding mill, 4 is a table, 9 is a table liner, 10 is a divided piece of the table liner, 11 is a gap between the divided pieces, 12 is a hard facing portion, 13, 13 ', 13 "are gap plates, 14 is a notch, 15 is a closing plate, and 16 is a weld.

Claims (1)

[Claims] 1. A plurality of divided pieces constituting a ring-shaped table liner in a vertical grinding mill or the like are arranged in a ring shape,
After forming a notch of a required width extending in the radial direction on the upper surface at the opposite end of each of the divided pieces, and inserting a closing plate between the opposite notches to close the gap between the divided pieces. After the surface of each of the divided pieces together with the closing plate is hardened by welding in the circumferential direction over the entire circumference, the hardened buildup and the closing plate are removed by removing the hardened buildup and the closing plate above the closing plate. A piece is produced, then the divided pieces are attached in a ring shape at a predetermined position on the table, a flat plate-like gap plate is vertically inserted into the gap between the divided pieces, and the upper portion of the gap plate and the notch Is welded with a welding rod having toughness to the same height as the bottom portion of the hardfacing portion of the divided piece, and after fixing the divided pieces and the gap plate, the hardfacing portion of the divided piece is provided above the welding portion. Hardfacing method for split liners, characterized by performing hardfacing welding at the same height as