阅读说明：本技术 一种钛合金用辅助电极的对焊方法 (Butt welding method of auxiliary electrode for titanium alloy ) 是由 孙治中 潘彦杰 刘鹏 赵小花 李耀斌 罗文忠 刘向宏 于 2019-10-30 设计创作，主要内容包括：本发明公开了一种钛合金用辅助电极的对焊方法,具体按照以下步骤实施：将报废料头预处理,得到待用料头；将待用料头装配在坩埚中,取待对焊辅助电极,并将该待对焊辅助电极对中连接在真空自耗电弧炉电极杆的气动夹头上；封闭真空自耗电弧炉,抽真空、打开循环水,当炉内真空不高于5Pa,漏率不高于1.2Pa/min,调节待对焊辅助电极对焊工艺参数；待对焊辅助电极已熔重量为2-5kg时,下压电极杆进行焊接；简单、易行,辅助电极对焊成功率100％的对焊方法,保证了辅助电极的对焊强度,极大地降低了辅助电极对焊的难度,规避了对人为因素的依赖,消除了常规对焊方法中产生大面积焊瘤的缺点。(The invention discloses a butt welding method of an auxiliary electrode for a titanium alloy, which is implemented according to the following steps: pretreating the scrapped stub bar to obtain a standby stub bar; assembling a stub bar to be used in a crucible, taking an auxiliary electrode to be butt-welded, and connecting the auxiliary electrode to be butt-welded on a pneumatic chuck of an electrode rod of a vacuum consumable electrode arc furnace in a centering manner; closing the vacuum consumable electrode arc furnace, vacuumizing, opening circulating water, and adjusting the butt welding technological parameters of the auxiliary electrode to be butt welded when the vacuum in the furnace is not higher than 5Pa and the leakage rate is not higher than 1.2 Pa/min; when the molten weight of the butt welding auxiliary electrode is 2-5kg, pressing an electrode rod downwards for welding; the butt welding method is simple and easy to implement, the butt welding power of the auxiliary electrode is 100%, the butt welding strength of the auxiliary electrode is guaranteed, the difficulty of butt welding of the auxiliary electrode is greatly reduced, dependence on human factors is avoided, and the defect that large-area welding beading is generated in the conventional butt welding method is overcome.)

1. A butt welding method of an auxiliary electrode for titanium alloy is characterized by comprising the following steps:

step 1, pre-treating a scrapped stub bar to obtain a standby stub bar;

step 2, assembling a stub bar to be used in a crucible, taking an auxiliary electrode to be butt-welded, and connecting the auxiliary electrode to be butt-welded on a pneumatic chuck of an electrode rod of the vacuum consumable electrode arc furnace in a centering manner;

step 3, closing the vacuum consumable electrode arc furnace, vacuumizing, opening circulating water, and adjusting the butt welding process parameters of the auxiliary electrode to be butt welded when the vacuum in the furnace is not higher than 5Pa and the leakage rate is not higher than 1.2 Pa/min;

and 4, pressing the electrode rod to weld when the molten weight of the butt welding auxiliary electrode is 2-5 kg.

2. The butt welding method of the auxiliary electrode for the titanium alloy according to claim 1, wherein the pretreatment process in step 1 is: classifying the scrapped stub bars according to the marks, and preparing the scrap heads into the stub bars to be used through turning, saw cutting, sand blasting and cleaning.

3. The butt welding method of an auxiliary electrode for titanium alloy according to claim 1, wherein the distance between the stub bar to be used and the inner wall of the crucible in step 2 is 0 to 5 mm.

4. The butt welding method of the auxiliary electrode for the titanium alloy according to claim 1, wherein the butt welding process parameters of the auxiliary electrode to be butt welded in the step 3 are shown in table 1:

TABLE 1

5. The butt welding method of the auxiliary electrode for the titanium alloy according to claim 1, further comprising the step 5 of turning off a power supply and stabilizing an arc, cooling for not less than 1 hour, then discharging gas from the furnace chamber, and taking out the auxiliary electrode.

Technical Field

The invention belongs to the technical field of butt welding processes of titanium alloys, and particularly relates to a butt welding method of an auxiliary electrode for a titanium alloy.

Background

The diameter of an auxiliary electrode used in the field of titanium alloy ingot smelting is generally less than or equal to phi 400mm, the diameter specification of the longest auxiliary electrode is in the range of phi 160 mm-phi 320mm, and butt welding auxiliary electrodes in the prior art mainly comprise the following steps:

1) classifying and screening scrapped auxiliary electrodes with different diameters and grades or forging residual stub bars;

2) turning, sawing, sand blasting and cleaning to prepare a to-be-used stub bar, wherein the end surface flatness of the stub bar is less than or equal to 3 mm;

3) assembling a stub bar in a crucible with the specification of phi 560mm, wherein the crucible gap is in the range of 80 mm-200 mm;

4) an auxiliary electrode (the diameter is less than or equal to 320mm generally) to be butt-welded is assembled on an electrode rod of the vacuum consumable electrode electric arc furnace, and the diameter of the auxiliary electrode is smaller than that of a welding head to be butt-welded, so that centering adjustment is carried out;

5) sealing the furnace chamber, vacuumizing and opening circulating water;

6) when the vacuum degree is less than or equal to 5Pa, the leakage rate is less than 1.2Pa/min, and butt welding is prepared by an experienced manipulator;

7) setting the arc striking to be 3kA, setting the voltage to be 24V, and then turning on a power supply to strike an arc for welding;

8) in the whole welding process, an operator continuously adjusts current, voltage and arc stabilizing parameters according to personal experience and the change conditions of a molten pool and arc light in the furnace to weld;

9) the condition of the molten pool is judged by an operator according to experience, and the electrode rod is pressed down at a correct time to finish welding;

10) and (5) after cooling for more than or equal to 1 hour, discharging gas from the furnace chamber, and discharging.

11) And (5) removing welding beading generated by butt welding, checking the welding quality, and putting into use if the welding quality meets the requirements.

Disclosure of Invention

The invention aims to provide a butt welding method of an auxiliary electrode for titanium alloy, which has no welding beading generation in the welding process and can improve the welding quality.

The technical scheme adopted by the invention is that the butt welding method of the auxiliary electrode for the titanium alloy is implemented according to the following steps:

step 1, pre-treating a scrapped stub bar to obtain a standby stub bar;

step 2, assembling a stub bar to be used in a crucible, taking an auxiliary electrode to be butt-welded, and connecting the auxiliary electrode to be butt-welded on a pneumatic chuck of an electrode rod of the vacuum consumable electrode arc furnace in a centering manner;

step 3, closing the vacuum consumable electrode arc furnace, vacuumizing, opening circulating water, and adjusting the butt welding process parameters of the auxiliary electrode to be butt welded when the vacuum in the furnace is not higher than 5Pa and the leakage rate is not higher than 1.2 Pa/min;

and 4, pressing the electrode rod to weld when the molten weight of the butt welding auxiliary electrode is 2-5 kg.

The invention is also characterized in that:

the pretreatment process in the step 1 is as follows: classifying the scrapped stub bars according to the marks, and preparing the scrap heads into the stub bars to be used through turning, saw cutting, sand blasting and cleaning.

And 2, the distance between the material head to be used and the inner wall of the crucible is 0-5 mm.

Step 3, the parameters of the auxiliary electrode to be butt welded are shown in table 1:

TABLE 1

Time/min	current/kA	voltage/V	Arc stabilization/A	Arc stabilization period/s
					Arcing	3.0	23.5	0	0
0.5	3.5	24	2～3	5
					1.0	4.0～4.5	24～24.5	2～5	5～10
1.5	4.0～4.5	24～24.5	2～5	5～10
					2.0	4.0～4.5	24～24.5	2～5	5～10
2.5	4.0～4.5	24～24.5	2～5	5～10
					3.0	4.5	24.5	2～5	5～10
3.5	5.0	24.5	2～5	5～10
					4.0	5.5	24.5	2～5	5～10
4.5	6.0	25	5～10	5～10
					5.0	6.5	25.5	5～10	5～10
5.5	7.0	26	5～10	5～10
					6.0	7.5	26.5	5～10	5～10
6.5	8.0	27	5～10	5～10
					7.0-15.0	8.0	27	5～10	5～10

。

And 5, turning off a power supply and stabilizing the arc, cooling for not less than 1h, discharging gas from the furnace chamber, and taking out the auxiliary electrode.

The invention has the beneficial effects that:

the butt welding method of the auxiliary electrode for the titanium alloy is simple and easy to implement, the butt welding power of the auxiliary electrode is 100%, the butt welding strength of the auxiliary electrode is guaranteed, the difficulty of butt welding of the auxiliary electrode is greatly reduced, dependence on human factors is avoided, and the defect that large-area welding beading is generated in a conventional butt welding method is overcome.

Drawings

FIG. 1 is a diagram illustrating the effect of butt welding using the prior art;

FIG. 2 is a graph showing the effect of the butt welding method of the present invention in example 1;

FIG. 3 is a graph showing the effect of the butt welding method of the present invention in example 2.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The invention relates to a butt welding method of an auxiliary electrode for a titanium alloy, which is implemented according to the following steps:

step 1, classifying the scrapped stub bars according to the marks, and preparing the stub bars to be used through turning, sawing, sand blasting and cleaning.

And 2, assembling the stub bar to be used in the crucible, wherein the distance between the stub bar to be used and the inner wall of the crucible is 0-5mm, taking the auxiliary electrode to be butt-welded, and connecting the auxiliary electrode to be butt-welded on a pneumatic chuck of an electrode rod of the vacuum consumable arc furnace in a centering manner.

Step 3, closing the vacuum consumable electrode arc furnace, vacuumizing, opening circulating water, and adjusting the butt welding process parameters of the auxiliary electrode to be butt welded when the vacuum in the furnace is not higher than 5Pa and the leakage rate is not higher than 1.2 Pa/min;

the parameters of the auxiliary electrode to be butt-welded are shown in table 1:

TABLE 1

And 4, pressing the electrode rod to weld when the molten weight of the butt welding auxiliary electrode is 2-5 kg.

And 5, turning off a power supply and stabilizing the arc, cooling for not less than 1h, discharging gas from the furnace chamber, and taking out the auxiliary electrode.

In order to illustrate the beneficial effects brought by the butt welding method of the present invention, the results of butt welding using the prior art are compared with the results of butt welding of the present invention, wherein fig. 1 is a diagram illustrating the effects of the prior butt welding method.