pure-tungsten: 八月 2015

2015年8月25日星期二

SMAW Tungsten Welding Wire

Shielded metal arc welding (SMAW), also known as manual metal arc welding (MMA or MMAW), flux shielded arc welding or informally as stick welding, is a manual arc welding process that uses a consumable electrode covered with a flux to lay the weld.

An electric current, in the form of either alternating current or direct current from a welding power supply, is used to form an electric arc between the electrode and the metals to be joined. The workpiece and the electrode melts forming the weld pool that cools to form a joint. As the weld is laid, the flux coating of the electrode disintegrates, giving off vapors that serve as a shielding gas and providing a layer of slag, both of which protect the weld area from atmospheric contamination.

Because of the versatility of the process and the simplicity of its equipment and operation, shielded metal arc welding is one of the world's first and most popular welding processes. It dominates other welding processes in the maintenance and repair industry, and though flux-cored arc welding is growing in popularity, SMAW continues to be used extensively in the construction of heavy steel structures and in industrial fabrication. The process is used primarily to weld iron and steels (including stainless steel) but aluminium, nickel and copper alloys can also be welded with this method.

Tungsten welding wire can be used as welding core wire in SMAW. The diameters of this kind of wire range a lot, but mostly are packed in rolls.

Further information, please contact sales@chinatungsten.com for more tungsten products, besides tungsten welding wire.

GMAW Tungsten Electrodes

Gas metal arc welding (GMAW), sometimes referred to by its subtypes metal inert gas (MIG) welding or metal active gas (MAG) welding, is a welding process in which an electric arc forms between a consumable wire electrode and the workpiece metal(s), which heats the workpiece metal(s), causing them to melt, and join.

Along with the wire electrode, a shielding gas feeds through the welding gun, which shields the process from contaminants in the air. The process can be semi-automatic or automatic. A constant voltage, direct current power source is most commonly used with GMAW, but constant current systems, as well as alternating current, can be used. There are four primary methods of metal transfer in GMAW, called globular, short-circuiting, spray, and pulsed-spray, each of which has distinct properties and corresponding advantages and limitations.

Tungsten is absolutely the electrode in GMAW welding. Tungsten electrodes, including cerium tungsten electrode, lanthanum tungsten electrode, thorium tungsten electrode, yttrium tungsten electrode, pure tungsten electrode and composite tungsten electrode, are mostly widely used.

The regular dimensions are(mm)

Ø1.6x150

Ø2.4x150

Ø3.2x150

Ø1.6x175

Ø2.4x175

Ø3.2x175

If there is any other question, please feel free to contact Chinatungsten:

Email:sales@chinatungsten.com

Tel.:86 592 5129696

Fax:86 592 5129797

2015年8月19日星期三

TIG Tungsten Electrode

Tungsten Inert Gas Welding for TIG as short name is a process of welding by using tungsten electrode under gas protection. This process can also be called as GTAW(Gas Tungsten Arc Weld).

The Operation is as following:

Manual gas tungsten arc welding is a relatively difficult welding method, due to the coordination required by the welder. Similar to torch welding, TIG normally requires two hands, since most applications require that the welder manually feed a filler metal into the weld area with one hand while manipulating the welding torch in the other. Maintaining a short arc length, while preventing contact between the electrode and the workpiece, is also important.

To strike the welding arc, a high frequency generator (similar to a Tesla coil) provides an electric spark. This spark is a conductive path for the welding current through the shielding gas and allows the arc to be initiated while the electrode and the workpiece are separated, typically about 1.5–3 mm (0.06–0.12 in) apart.

Once the arc is struck, the welder moves the torch in a small circle to create a welding pool, the size of which depends on the size of the electrode and the amount of current. While maintaining a constant separation between the electrode and the workpiece, the operator then moves the torch back slightly and tilts it backward about 10–15 degrees from vertical. Filler metal is added manually to the front end of the weld pool as it is needed.

Welders often develop a technique of rapidly alternating between moving the torch forward (to advance the weld pool) and adding filler metal. The filler rod is withdrawn from the weld pool each time the electrode advances, but it is always kept inside the gas shield to prevent oxidation of its surface and contamination of the weld. Filler rods composed of metals with a low melting temperature, such as aluminum, require that the operator maintain some distance from the arc while staying inside the gas shield. If held too close to the arc, the filler rod can melt before it makes contact with the weld puddle. As the weld nears completion, the arc current is often gradually reduced to allow the weld crater to solidify and prevent the formation of crater cracks at the end of the weld.

Chinatungsten can provide you many kinds of tungsten electrodes for GTAW welding:

Pure tungsten electrode (WP)

Thorium tungsten electrode (WT20)

Cerium tungsten electrode (WC20)

Lanthanum tungsten electrode (WL15, WL20)

Zirconium tungsten electrode (WZ3, WZ8)

Yttrium tungsten electrode (WY20)

Composite tungsten electrode

If you have got any question, kindly please contact sales@chinatungsten.com for more information.

GTAW Tungsten Electrode

The whole name for GTAW is Gas Tungsten Arc Weld, which is used to describe a process that uses a non-consumable tungsten electrode to produce the weld. The weld area is protected from atmospheric contamination by an inert shielding gas (argon or helium), and a filler metal is normally used, though some welds, known as autogenous welds, do not require it. A constant-current welding power supply produces electrical energy, which is conducted across the arc through a column of highly ionized gas and metal vapors known as a plasma.

GTAW is most commonly used to weld thin sections of stainless steel and non-ferrous metals such as aluminum, magnesium, and copper alloys. The process grants the operator greater control over the weld than competing processes such as shielded metal arc welding and gas metal arc welding, allowing for stronger, higher quality welds. However, GTAW is comparatively more complex and difficult to master, and furthermore, it is significantly slower than most other welding techniques. A related process, plasma arc welding, uses a slightly different welding torch to create a more focused welding arc and as a result is often automated.