Inverters Add Key Benefits:

A quick review is in order. About 30 years ago, Miller Electric invented and patented the squarewave AC output and adjustable balance control function found in its line of Syncrowave® TIG welders. This technology made the transition through the zero amperage range faster than a regular sine wave, which improved arc starts and created a more stable arc. With balance control, the operator could change the duration of the AC half cycle, adjusting the electrode negative (EN) from 32 up to 68 percent.

Today, the next generation of this technology - AC TIG inverter - features three advanced squarewave technology capabilities.

First: The AC TIG inverter produces incredibly smooth, stable arcs because the squarewave is driven through the zero point thousands of times faster than a rectifier-based welder. Miller's Dynasty® inverters are so fast that its built-in, high frequency capabilities are used for arc starting only. They also offer Lift-Arc™ starting capabilities to eliminate the use of high frequency completely, even on AC.

Second: Inverter-based welders extend EN balance control. The Dynasty lets operators fine-tune duration times from 50 percent to 90 percent. Making the EN portion of cycle last longer achieves greater penetration; narrows the weld bead; increases travel speeds up to 20 percent; may permit using a smaller diameter tungsten to more precisely direct the heat or make a narrower weld bead; and, reduces the size of the etched zone for improved cosmetics.

Third: Inverter-based welders let operators adjust the welding output frequency, from 20 to 250 Hz in the case of the Dynasty. Conventional welders have a fixed output of 60 Hz. Lowering the frequency produces a broader arc cone, widening the weld bead profile, which is great for build-up work. Increasing frequency above 60 Hz produces a tight, focused arc cone. This pinpoint heat control drives more heat into the weldment for better penetration and a narrower weld bead, which helps when welding in corners, on root passes and fillet welds or anywhere precision welding is required.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten Picture Center: http://picture.chinatungsten.com
Tungsten Video Center: http://v.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com

For as long as anyone can remember, the prevailing wisdom was that in order to get the best results, anyone who was TIG welding aluminum, magnesium or other alloys that required an AC arc had to use a pure tungsten electrode.

But not anymore. For the last five years the industry has made a dramatic shift toward inverter-based AC TIG welders that incorporate advanced squarewave technology to improve weld quality, increase travel speed and reduce operating costs.

However, in order to gain the maximum benefits from inverter technology, selecting the right tungsten now becomes an increasingly more critical issue. In the past, pure tungsten was the only choice for AC TIG welding. But that's no longer the case with the latest inverter technology. Today, industry experts recommend against pure tungsten in favor of the new "rare earth" tungstens. By adding elements such as cerium or lanthanum these electrodes outperform pure tungsten.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten Picture Center: http://picture.chinatungsten.com
Tungsten Video Center: http://v.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com

1. Preparatory work
(1) be familiar with the pattern and process planning, master of the location, size and requirements of the welding, a reasonable choice of welding method and order.
(2) clean up the workplace, aids and protective equipment.
(3) Check the equipment. The adjusting mechanism on the welder, wire, cable and grounding is good; handle insulation is good, the ground wire and the workpiece connection is reliable; by sea, air, road is smooth; high frequency or pulsed arc initiation and stability whether good.
(4) Check the workpiece. Slag, dirt, grease, sand and other objects may not exist in the groove weld both sides of the 20mm range, not oil, rust, welding wire for degreasing rust.
(5) do not place in the outlet or forced ventilation welding.
(6) According to the process documentation and product design requirements, the correct choice of welding wire.

2. Security technology
(1) the wearing of personal protective equipment, work in well-ventilated environment, the workplace to prevent humid and filled with water, is strictly prohibited stacked flammable liquids.
(2) of the workpiece must be reliably grounded when welding with DC power, attention to reducing the operating time of the high-frequency electric arc to cut off the high frequency power supply.
(3) welding must use compressed air to the water in the entire waterway system blowing, in order to avoid frozen pipes.
(4) grinding tungsten to wear gloves and masks.

3. Process parameter selection
Gas tungsten arc welding process parameters are mainly the type and polarity of the welding current, welding current, tungsten diameter and shape of the ends to protect the gas flow.
(1) Welding current type and size generally select the current type of workpiece material. The size of the welding current is the most important parameters to determine the weld penetration depth, it is mainly based on workpiece material, thickness, joint type, welding position to choose, and sometimes also consider the factors of welders technical level (manual welding).
(2) The shape of the tungsten diameter and ends tungsten electrode diameter according to the welding current size of the current polarity selection (see Table 3-14).
Tungsten extreme head shape is an important process parameters. According to the type of welding current is used, the choice of a different shape of the ends, as shown in Figure 3-11 shows, the state-of-the-art point of view. The size of the tungsten allowable current, arc starting and arc stability, Table 3-15 lists the recommended current range of state-of-the-art size tungsten different.
(3) gas flow rate and nozzle diameter welding quality depends largely on the protective effect of argon. Under certain conditions, the gas flow rate and nozzle diameter of one of the best range, at this time, gas protection is best, effective protected areas. Table 3-16 shows the welding current and nozzle diameter, gas flow relationship.
Argon protective effect of the assessment is mainly based on the color of the weld surface. Welding the protective effect of surface color and gas are shown in Table 3-17.

4. Operating techniques
TIG operating techniques, including arc, filler wire welding, the closing arc process.
(1) arc
① short circuit arc method (contact arc method), tungsten, weldments instantaneous short-circuit, immediately a little mention, the arc between the weldment and tungsten;
② frequency arc method, the use of high-frequency arc starter ordinary frequency alternating current (220V or 380V, 50Hz) to convert the high-frequency (150 ~ a 260kHz), high pressure (2000 ~ 3000V), the argon gas breakdown ionizing , in order to ignite the arc.
(2) closing arc
(1) increase the welding speed method, welding torch, welding will be terminated gradually increase the speed of mobile;
(2) current decay welding termination, stop the filler wire welding current is gradually reduced, so that the molten pool size is shrinking, the last power outage, the welding gun or torch to stop walking.
(3) filler wire welding with filler wire must wait before they can fill in the parent metal melted fully added in order to avoid lack of fusion, filling the position to fill the bath cutting-edge site, and wire to recover, try not to immediately out of the argon gas protected areas.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten Picture Center: http://picture.chinatungsten.com
Tungsten Video Center: http://v.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com

The TIG harmful factors
Argon arc welding affect the body of harmful factors in three areas:
1, radioactive
Thorium tungsten thorium is a radioactive element, thorium tungsten tungsten arc welding radiation dose is very small, within the allowable range, there is little risk. If the radioactive gases or particles into the body as within the radioactive source, it will seriously affect their health.
2, high-frequency electromagnetic field
Using high-frequency arc, the high-frequency electromagnetic field strength between 60 ~ 110V / m, more than the health standard (20V / m) several times. But since time is very short, has little effect on the human body. Frequent starting arc, or the continued use of the high-frequency oscillator as a stable arc device in the welding process, the high-frequency electromagnetic fields can become one of the harmful factors.
3, the harmful gases - ozone and nitrogen oxides
Argon arc, the arc column temperature. UV radiation is much larger than the general arc welding in the welding process to produce large amounts of ozone and nitrogen oxides; In particular, the ozone concentration is far above the reference health standard. If you do not take effective ventilation, these gases impact on human health, argon arc welding the main harmful factors.
Second, the security measures
1, ventilation measures
Argon arc welding work site should have good ventilation, the discharge of harmful gases and dust. In addition to the plant ventilation, welding capacity, welder concentration install several axial flow fan out the exhaust.
In addition, measures can be applied to local exhaust ventilation will arc around the harmful gases siphoned, such as open arc exhaust hood, exhaust gas torch, light a small fan.
Protective ray measures
Maximize the use of very low radiation dose of cerium tungsten. Thorium-tungsten and cerium tungsten processing, should be sealed or exhaust the grinding wheel, the operator should wear personal protective equipment such as masks, gloves, face and hands should be washed after processing. Thorium tungsten and cerium tungsten pole should be placed on aluminum box within save.
3, high-frequency protection measures
Preparedness and weaken the influence of high frequency electromagnetic fields, the measures taken are:
(1) The workpiece is well grounded, the torch cable and ground use metal braided wire shield;
(2) the appropriate lower frequency;
(3) Try not to use high-frequency oscillator as a stable arc device, reducing the duration of action of high frequency electricity.
(4) other personal protective measures
Argon arc when, due to ozone and ultraviolet rays are strongly advised to wear non-cotton clothes (such as acid, tussah silk, etc.). Welding inside the container can not use local exhaust ventilation, air helmet and air mask or anti-virus masks and other personal protective measures.
 

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten Picture Center: http://picture.chinatungsten.com
Tungsten Video Center: http://v.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com

WT thorium tungsten:
Abroad, the most commonly used tungsten electrode. Easy arc starting, arc stability. But with traces of radioactivity are widely used in DC welding. Typically used for DC welding of carbon steel, stainless steel, nickel alloys and titanium.
WC cerium tungsten:
Currently widely used as a Electron emission capacity thorium tungsten is ideal to replace the thorium tungsten non-radioactive materials. In DC or AC welding, especially on the rail in a small current pipeline, the best welding of small precision parts.
WL lanthanum tungsten:
High-current DC and AC, are applicable. Lanthanum tungsten closest to the conductive properties of thorium, tungsten, without changing any of the welding parameters can be a convenient alternative thorium tungsten, and maximize the use of effects.
WZ zirconium tungsten:
For AC welding, under special conditions need to prevent electrode contamination of the weld metal. Performed well under high load currents. AC welding for magnesium, aluminum and its alloys.
WY yttrium tungsten:
In welding, the arc beam slender, compressed large extent, in the medium and high current penetration maximum. Plastic made ​​from 1mm thick sheet and a variety of bar and wire. Mainly used in military and aerospace industry.
 

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten Picture Center: http://picture.chinatungsten.com
Tungsten Video Center: http://v.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com

The use intensity of tungsten carbide brazing tool stands for the work ability of the tool without damage. The coefficient K representes the use intensity. The coefficient K is  the workload ratio between the actual amount of work done and the actual amount of work to complete in the non-manufacturing scrap and  conditions of no damage . In order to use a statistical method to determine the coefficient K, we must accumulate large amounts of data of the tool working ability. Within constant condition of tool using case, for example, for a company which produces fixed production in several years, the change of the coefficient K means a change in the quality of the tool. Continuously monitoring the coefficient values​​, you can get the data of tool in the loss of non-production areas and improving the potential of the tool quality.


Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.tungsten-carbide.com.cn
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten Picture Center: http://picture.chinatungsten.com
Tungsten Video Center: http://v.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com

A detailed chart with hole and location dimensions as well as manufacturing tolerances is available for each standard configuration.
 
A Material Description Data Sheet is available for each tungsten carbide rod grade.
 
2H30 - Tungsten Carbide Rods 310mm or 330mm long with two holes twisted to 30° helix
2H40 - Tungsten Carbide Rods 310mm or 330mm long with two holes twisted to 40° helix
3H30 - Tungsten Carbide Rods 310mm or 330mm long with three holes twisted to 30° helix
3H40 - Tungsten Carbide Rods 310mm or 330mm long with three holes twisted to 40° helix
2SH - Tungsten Carbide Rods 310mm or 330mm long with two straight parallel coolant holes
2CLH - Tungsten Carbide Rods 310mm or 330mm long with two straight parallel coolant holes and reduced bolt hole circle
CH - Tungsten Carbide Rods 310mm or 330mm long with one straight central coolant hole
SOLID - Tungsten Carbide Rods 310mm or 330mm long with no holes
Milling Cutter Blanks - Tungsten Carbide Rods with one central hole and one to five lateral exits.


Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.tungsten-carbide.com.cn
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten Picture Center: http://picture.chinatungsten.com
Tungsten Video Center: http://v.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com

Through the analysis, tungsten concentrate price continues to rise.

According to import & export data of February, some product’s prices began to recover while exports are declining. It would be great influence on domestic tungsten concentrate price. As a result, the foreign demand would shrink accordingly. Another important reason for the tungsten concentrate recovery is the beneficial regulation forwarded by local policies.

Now, due to demand of capital construction, machinery and processing, etc, lower down the developing steps, our national larger the right of tungsten concentrate manufacturer, therefore, the price has been accelerate the pace of recovery. So tungsten concentrate price will be in the trend of increasing in May.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.tungsten-carbide.com.cn
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten Picture Center: http://picture.chinatungsten.com
Tungsten Video Center: http://v.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com

There is an abundance of concern and discomfort with China’s grasp on the tungsten market. The Chinese government only exacerbates these sentiments with its export quota policy, which restricts how much of the metal can be sold outside of the country. As these quotas have become stricter, the world’s rations have gotten smaller.

A number of theories exist in the tungsten industry in regards to China’s motives for increasing its stranglehold on the metal. Some point to the nation’s rising domestic demand for tungsten and note that China’s producers are experiencing rising costs, falling grades, increasing environmental concerns, and stricter regulations. Some believe the Chinese may be stockpiling tungsten for future use.

The tungsten industry is largely characterized by dependence and uncertainty, but there is also the potential for profit. Tungsten prices have gone from about $180 to $430 per metric ton unit (mtu) over the course of three years. Last year, highs of up to $500/mtu were reported.

"That [the factors noted above] is why a company like IMC, which is 80 percent owned by Warren Buffet, would come to Woulfe Mining and want to purchase 25 percent of our tungsten project, and more importantly is guaranteeing to buy 90 to 100 percent of all the resource we can produce," said Smith.

He also said that people who have tungsten mines in operation, or about to come into operation outside of China, are in a very strong position not only to provide tungsten to the western world, but also to China, which has become a net importer of the metal.

But, Tungsten Investing News, asked Smith, are there other opportunities in the market like the Woulfe-IMC deal, where end users are looking to establish a relationship?

"Yes," he said. "I think that most people that are producing resources will be having similar conversations."

The interest in obtaining a supply outside of China is growing, and is a trend that is likely to continue. But while there are attractive opportunities, the risks must be assessed as well.

One risk is that China will engage in practices that reduce or impair competition in the mining space and among end users. This situation could occur in a variety of ways, such as through a restriction of supply or the flooding of the market and lowering of prices below economically viable levels.

To ignore these possibilities would be to overlook history. In the past, China has flooded the market with cheap tungsten, lowering the price the price of WO3 concentrate and APT, and causing exploration companies, miners, and, processors to close their businesses.

Ecclestone said, "the Chinese as both the largest producer and one of the main users have a vested interest in higher prices but that does not mean that they may not push prices down to achieve other policy or strategic goals."

With regard to supply disruptions that benefit Chinese toolmakers while hurting foreign competitors, Ecclestone noted that "if any investors doubt that that might happen then they would be naïve indeed."

This comment highlights one of the reasons why offtake agreements, contracts in which a buyer commits to future purchases, are especially attractive in the tungsten space. By signing them, miners are able to secure sales, a commitment that translates into reduced risk to equity investors.