For every welder, the knowledge of the difference between AC and DC welding is very essential. Every professional welder knows how crucial it is to use the appropriate power settings with a certain type of material in order to get the top-notch flawless result.

Overtimes, being aware of this will not only help you to become an efficient welder but also will periodically develop intuitive wisdom inside you by which you can predetermine the appropriate power settings through conducting a plethora amount of experiments.

Now let’s take a due look at the definition, applications, advantages & disadvantages of AC and DC welding:

AC Welding

The term AC refers to as alternating current which means the current switches its position 120 times per second in polarity between DC negative and DC positive. One of the top advantages of using AC welding is its zero deflection rate and also the ability to weld ferrous & magnetic materials efficiently.

Application areas of AC welding

AC welding is apparently one of the frequently used processes for operating all sorts of high voltage electrical devices such as home appliances and machinery.

But on the other hand, the transformer required to supply AC power is quite inexpensive and requires less maintenance cost. Overall, it’s a go-to power source for all sorts of ferrous and magnetic materials.

We all know it’s quite difficult to effortlessly weld heavy plate metals. But with AC welding, you can conveniently weld them in a down hand or horizontally flat position.

Another common area where AC welding is used is over fast filling. This is basically performed by using a fast-fill electrode that features a higher deposition rate.

Now, you may be aware that aluminum requires comparatively higher temperature in order to get weld. Besides, you are required to use the TIG welding process for welding aluminum. Now since AC welding is the best power supply for welding most sort of TIG welding materials, all-aluminum made products are manufactured using AC welding.

Finally, one of the crucial areas where AC welding is performed is over repairing machinery equipment. Now it’s a common fact that machinery and equipment contain magnetized field. Besides, using them for a longer period will potentially result in rusty condition over their body.

In this case, if you are to weld them using DC power, it would have damaged them because of high heat and deeper penetration. For this, AC welding power is primarily used for repairing these instruments.

Advantages of AC welding

  • Due to the nature of this process, AC welding can be effortlessly used over heavy-duty materials like aluminum and fast fill.
  • It is a proven fact that magnetized materials tend to influence arc blow which is mostly seen in DC welding process. But because AC welding changes its polarity frequently the chances of occurring that situation is close to zero.
  • AC welding allows you to weld at a higher temperature without facing any issues. Consequently, you can be able to TIG weld heavy-duty materials at ease
  • AC welding is very cost-efficient since there are no moving parts in its transformer and it requires very low maintenance.
  • AC welding can be connected over any terminal.
  • Finally, since it features less energy consumption with high temperature, a deeply penetrated weld while having cost-efficiency can be performed by using AC welding.

Disadvantages of AC welding

  • You cannot weld non-ferrous materials with AC welding
  • AC welding generates more spatter than that of DC welding
  • The arc seems to be quite unstable when working on AC welding
  • You can be able to weld most stick welding applications by using DC welding which isn’t suitable in case of AC power.

Some Additional Issues Associated with AC Welding

Now that we know the polarity per second is super high in AC welding and the current changes its position frequently, it also makes us unable to weld with all sorts of electrodes other than coated ones only.

Although AC welding has very less feasibility of occurring arc blow, it is generally used in rare circumstances and as a secondary power supply for most welding processes.

DC Welding

The term DC refers to as direct current which means the electrons are always traveling in a constant direction. The polarity of DC welding is also constant which can be presented in a negative or positive way. One of the major features of the negative DC is its greater deposition rates whereas DC positive is mostly used for providing deeper penetration.

Application areas of DC welding

In general, DC welding is the most frequently used form of power supply in welding because of its material diversity. You can weld almost all sorts of materials using DC power.

You may already know AC welding features only ferrous materials. But with DC welding, you’ll have the flexibility to use it over either of them including non-ferrous materials.

Now, another convenient feature of DC welding is the ability to weld vertically over materials. This way you can weld on overhead positions.

It’s a general fact that DC welding produces the smoothest weld than that of AC welding and is very less likely to occur any spatter because of the constant power supply.

All sorts of stick welding applications are performed using DC welding. Besides, you can effortlessly TIG weld stainless steel materials by using DC power.

DC welding is best for providing higher deposition rates and also features hard facing with single carbon brazing.

DC welding is also used for joining thinner materials at ease.

Advantages of DC welding

  • DC welding is best for effortlessly welding thinner materials which are quite challenging in AC welding
  • The amount of spatter is very less in DC welding which ensures a cleaner and smoother weld of the joint.
  • Since welding is performed over lower voltage, it ensures safe operation of the whole task
  • It can weld both ferrous and nonferrous materials efficiently
  • You’ll be able to enjoy a stable arc during the whole welding process
  • DC welding is best for getting higher deposition rates and is more convenient to operate and reliable than that of AC welding

Disadvantages of DC welding

  • The risk of occurring arc blow is more in DC welding
  • The instruments needed to supply DC current is way expensive than AC welding
  • Because of the lacking in intensity and heat in DC welding, you are not supposed to weld aluminum properly.
  • The power consumption in DC welding is quite high which also indicates higher maintenance cost.

Some Additional Issues Associated With DC Welding

DC welding is the most popular and preferred means of power supply for most welders. Since you’re always getting the smoothest weld and it enables you to weld over any material, DC power can be your best source for carrying out most welding works.

AC vs DC Welding: Comparison Video

Final Words

Thanks for reading the whole post. We believe you have discovered one of the essential areas of welding in a very simple and precious way which is about the difference between AC and DC welding. Check out more articles and guides on our website we’ve exclusively produced for you. Stay along with us. Thanks.

My name is Gary P. Hargrave. I started this website to enlighten and help train the thousands of potential welders out there on the nitty-gritties of this job. In this industry, I believe that passion is everything. Read my story here.