DCEP supplies about two-thirds of the heat at the end of the rod, which allows more digging action, or penetration, into the base metal. It's what you want to use for thick steel. For thin steel, direct current electrode negative (DCEN) is best.
It is depend on machine
two reasons i can think of: 1 - Probably dont need to, usually welding material of constant thickness. 2 - The transformer is mechanically adjusted on most welders, this means that that there would be a possibility for electricity jumping in the transformer, and premature failure, or fire.
6010 is intended for DC welding. It has no additives in the covering to keep the arc going each time the AC voltage reverses, so it is very hard to keep the arc struck. The result is usually poor quality welds. The solution is to switch to a rod designed for AC, such as 6013.
what are gas welding limitation
in arc welding only heat is used to weld metal. but in resistance welding pressure will also be used along with heat.
The electrode. In some cases thin materials weld better with DCEN.
Polarity in welding has to do with the direction of the current in the welding process. With direct current (DC) the welding circuit can either be straight, or reverse polarity. When the machine is set for straight polarity, the current flows from the electrode to the weld surface and creates considerable heat in the metal. When the machine is in reverse polarity, the current is backwards and is flowing from the metal to the electrode causing a grater concentration of heat at the electrode.
Think of Polarity as water flow in a pipe. Reverse Polarity means the flow is from the work to the machine. Straight Polarity is flow from the machine to the work. Heat is released when the flow tries to jump the gap. So in Reverse Polarity (where most SMAW is done) the heat builds up in the base metal which is usually thicker than the Electrode. The extra heat there helps melt the base metal. Straight polarity is usually employed when welding thin metals.
Different material welds differently depending on polarity. There are also different types of welding rods, so polarity must be tested.
Transformer type welding machine
we will have straight polarity and reverse polarity,we can produce the weld with good quality
AC (Alternating Current) and DC (Direct Current) is used to describe the polarity of the electric current that the welder generates and in what direction it travels. If you use the wrong polarity for a certain welding rod, your weld strength will not be very good. The general terms associated with polarity are reverse polarity and straight polarity. These are common to the welding trade. Another way to describe the two terms are electrode positive and electrode negative. Electrode positive is the same as reverse polarity. Electrode negative is the same as straight polarity. Hence the + and the - written on your welder where the cables connect to it. Any type of welding rod you buy will be labeled as to what polarity should be used for welding with it. Using the correct polarity will ensure the proper penetration and the over all look of the final bead. If you use the wrong polarity you can tell by the signs. There will be an excessive amount of spatter, you will have bad penetration, and you will have less control of your arc. Some welding machines have a switch to adjust the polarity. If your welder doesn't have one you will need to switch the welding cables around where they plug into the machine. If you want reverse polarity, you need to make sure the electrode holder is plugged into the + terminal. The easiest way to tell if you are using the wrong polarity is by the sound and the feel of the weld you are laying down. If you don't have much experience with stick welding you will have a little more trouble determining the difference. I have seen guys weld all day long with the wrong polarity. Then I would grab their welder to use for couple of minutes and I could tell right away. It all comes down to experience.
dcrp = direct current reverse polarity
Transformer type welding machine
Advani company was manufactured the first welding machine
reverse polarity and straight polarity The answer is right but a bit of furthur explanation is required. Polarity can be changed in DC output welding sets. The heat of the welding arc is concentrated on the positive terminal. So when thick plates are welded as more concentration of heat is required on the job the job is kept +ve ie. straight polarity is used. For thin plates concentration of heat is on the filler rod ,so reverse polarity is used.
The only way to tig is to have your ground clamp hooked to the positive side of the welding machine. The negative lead will go to the tig torch. If it is reversed you will find out very quickly when you strike an arc. Most metals will be welded using this Polarity (straight). Most Aluminum TIG welding is performed using A C current.