JPS6199576A - Roll build-up welding method - Google Patents

Abstract

PURPOSE:To elevate the spalling of a slag and to improve the man/hour of a work by changing the welding method of the large bore end part of a mild steel base material from a submerge arc welding method to CO2 semi-automatic welding method. CONSTITUTION:A roll mild steel base material 11 is welded upto its bank part with making the angle of the positioner for rotation supporting it constant and with performing a multilayer build-up welding with adding a flux to a wear resistant hardening build-up welding material by a submerge arc welding method. The large bore end part of the base material 11 is in succession subjected to a hardening build-up welding by a CO2 semi-automatic arc welding method with rotating the base material 11 upto reaching the bank part of the base material 11 with using the wire containing a flux for CO2 arc welding and the build-up welding part 13 of the large bore end part is obtd. A dressed build-up welding part 14 is then obtd. so as to make the final finishing part of the base material 11 a plane face by the submerge arc welding method. A hardened build-up roll 15 is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a roll overlay welding method, and mainly relates to a roll overlay welding method for a roller mill of a pulverized coal combustion device.

[Conventional technology]

Conventionally, a method shown in FIG. 2, for example, is known as a roll overlay welding method.

First, the circumferential portion of the roll mild steel base material 1 is subjected to multilayer hardfacing welding by submerged arc welding while rotating the mild steel base material 1 itself, thereby forming the first multilayer hardfacing welded portion 2. Next, the large-diameter end of the mild steel base material 1 is subjected to multilayer hardening welding using the same welding method as described above while changing the angle of the positioner that rotates the mild steel base material 1, thereby forming a second multilayer hardening. A built-up welding portion 3 is formed. Next, the final finished surface of the mild steel base material 1 is subjected to cosmetic hardfacing welding by the same welding method as described above to form the final built-up finishing portion 4. In addition, 5 in the figure indicates the hardfacing roll obtained through the above steps,
6 indicates a submerged arc welding torch.

[The color point that the invention attempts to solve]

However, the conventional method has the following drawbacks.

■The hardfacing bath welding of the large diameter end of the mild steel base metal 1 is performed continuously using the submerged arc welding method, but because the end welding is welding, flux retention is difficult and the number of work steps is high. many. In addition, for the same reason, the welded part becomes hot and the peelability of the slab is poor.

■The cost of welding materials is high because an expensive soft overlay material similar to that used on the circumference of the mild steel base metal 1 is continuously hard overlaid welded to the large diameter end where wear resistance is not required as much. .

(2) When bath welding the large-diameter end of the mild steel base material 1 using the submerged arc welding method, the angles of the pins and knurs that support and rotate the mild steel base material 1 must be changed at any time, resulting in poor workability.

The present invention was made in view of the above circumstances, and it not only improves the workability of flux retention and slag peeling, but also reduces the cost of welding materials, and further enables welding regardless of the angle of the body and groove. The purpose of the present invention is to provide a method for overlaying rolls.

[Means for solving problems]

j The present invention includes a step of hardfacing welding the circumferential portion of a rolled mild steel base material by submerged arc welding, and a process of hardfacing the large diameter end of the mild steel base material by CO2 semi-automatic welding or MIG.
, characterized by comprising a step of hard overlay welding by MAG welding method, and a step of performing decorative overlay welding of the final finished part of the mild steel base material by submerged arc welding method, aiming at achieving the above object. The main point is

[Effect]

According to the present invention, the following effects can be mainly achieved.

■ By changing the welding method for the large-diameter end of the mild steel base material from submerged arc welding to CO2 semi-automatic arc welding, the slag removability is improved and the number of work steps is improved.

■ Reducing welding material costs by replacing the welding material for large-diameter ends of mild steel base metals from the conventional hardfacing welding wire for submerged arc welding to flux-cored shear wire for carbon dioxide arc welding, which does not place much emphasis on wear-resistant tubes. To aim for.

The present invention can be applied to (1) a repair overlay welding method for the end face of a roll for crushing rock or coal or for steel mill rolling, and (2) a hard overlay welding method for the cutting edge of a crusher, etc.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIG. 1 and FIGS. 3 to 5. In this example, the chemical composition and welding conditions of the welding material at the circumference, large-diameter end, and final finish of the roll mild steel base material are as shown in the table below, and the welding conditions at each welding location are as follows: The welding procedure is as shown in Figs. 3 to 5.

1. Roll soft and hard base material (hereinafter referred to as mild steel base material) 1.
While keeping the angle of the rotating positioner that supports the mild steel base material J1 constant, a high carbon, high chromium based wear-resistant hardfacing welding material was continuously applied using the submerged arc welding method while adding 7 Lanox. Multi-layer overlay welding, mild steel base material 11
The bath was accessed up to the bank. As a result, a multilayer hardfacing welded part J2 was obtained by the submerged arc welding method (as shown in FIG. 3). Next, the large-diameter end of the mild steel base material 11 is welded using a CO2 semi-automatic arc welding method while rotating the mild steel base material 11, using a flux-cored wire for carbon dioxide arc welding, until it reaches the bank of the mild steel base material 11. Performed welding. As a result, a large-diameter end overlay welded portion 13 was obtained using the CO2 semi-automatic arc welding method (as shown in FIG. 4). In addition, in this step, the angular displacement of the bonsai was not changed. Next, the final finished part of the mild steel base material 11 was subjected to decorative overlay welding by submerged arc welding while rotating the mild steel base material 11 so that the finished part became a flat surface.

As a result, a decorative overlay welded portion 14 was obtained by the submerged arc welding method, and a hard overlay roll 15 was manufactured (as shown in FIG. 5). Note that 16 in the figure indicates a sub-arc welding torch, and J7 indicates a CO□ semi-automatic arc welding torch.

According to the present invention, the following effects are achieved.

(2) When welding the large-diameter end of the mild steel base material 11, a CO2 semi-automatic arc welding method is used instead of the conventional submerged arc welding method, so that the slag releasability can be improved.

(2) For the same reasons as (2), there is no need to change the positioner that supports the mild steel base material 11 from time to time, and there is no need to hold flux, so the number of work steps can be significantly reduced.

■ When welding the large-diameter end of the mild steel base material 11, a slack-cored shear wire for carbon dioxide arc welding that is capable of semi-automatic arc welding is used, so the cost of welding materials can be reduced.In the above example, the roll mild steel base material Although the CO2 semi-automatic welding method was used to weld the large diameter end of the welding material, the present invention is not limited thereto. For example, MIG welding or HMAG welding may be used.

〔Effect of the invention〕

As detailed above, according to the present invention, it is possible to improve the workability of maintaining flux and peeling off slag, reduce the cost of one welding material, and furthermore, it is possible to create a roll that can be welded regardless of the angle of the body and the groove. It is possible to provide an overlay welding method.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a roll overlay welding method according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of a conventional roll overlay welding method, and FIGS. 3 to 5 are explanatory diagrams of a roll overlay welding method according to an embodiment of the present invention. This is a diagram to clearly explain the welding procedure of the roll overlay welding method. DESCRIPTION OF SYMBOLS 11... Roll soft hard base material, 12... Multilayer hard overlay welding part, 13... Large diameter end overlay welding part, 14... Decorative overlay welding part, 15... Hardened metal Served roll. Applicant Sub-Attorney Patent Attorney Takehiko Suzue Procedural Amendment (on the side), 60, 42, 2.88 Manabu Shiga, Commissioner of the Patent Office ■, Patent Application No. 1982-219973 No. 2 , Name of the invention Method for overlaying welding of rolls 3, with amendments Relationship to the case Patent applicant (620) Sanbin Heavy Industries Co., Ltd. 4 Successor agent 7 Amended 1 As shown in the attached sheet, in the drawings K “Figure 5” has been added and the figure number has been changed to “Figure 5”.

Claims (1)

[Claims] A method for overlaying a high carbon, high chromium roll mild steel base material, the process includes hard overlay welding the circumferential portion of the roll mild steel base material by submerged arc welding, and the large diameter end portion of the mild steel base material. CO_2 semi-automatic welding method or MIG, MAG
A roll overlay welding method comprising the steps of hard overlay welding by a welding method, and decorative overlay welding of the final finished portion of the mild steel base material by a submerged arc welding method.