# Heat Calculation In Hot Wire TIG

• posted

Hello to all , I heard that Hot Wire TIG is having high deposition rate than normal TIG, is the fact behind this is 'only the additional power source which we use for heating filler wire' ? is there any heat estimation calculation which leads to the conclusion that, the total arc energy (produced by Tungsten Electrode) is being utilised by parent metal? Can we use the formula of heat energy which is = (mass) * (Sp. heat of material)

*(Temp. Difference)? if yes then how we will take appropriate care for taking the value of specific heat of material (e.g steel), which generally remain constant upto 234 deg. F? & lastly what will be the value of diluation for Hot Wire TIG welding
• posted

Not sure exactly what you're getting at, but this comment relates, I think. The GTAW energy transfer efficiency is around 70% of the arc amps x volts, see link

my guess is that the watt resistance heating of the hot wire is nearly 100% transfered to the weld.

How could you know dilution unless you cross section and etch the weld to see the extent of the melt?

• posted

Hello Ipeak, Thanks for the reply.See basically I am finding the answer of question that is 'How the deposition rate of Hot Wire TIG is greater than that of TIG?' & I got the answer which is, ' Due to the heat energy'.Explanation- "when we do the TIG welding the heat energy produced by the arc (Considering 70% efficency) is distributed among parent metal & filler wire, hence to get the total heat for parent & filler metal which will be repossible for melting them, will be available if & only if we wait for sometime to get the required melting temperature" ( that is, as the time increases, the temperature of both will increase), right! Now in order to find the heat energy required by the parent metal & filler metal, I should aware of their dilution percentage,right! & from literature survey I came to know that the dilution in Hot Wire TIG welding is 40 to 45%. Now after knowing this much (Dilution, Sp.Heat of metal & Temperature Difference), should I go for ' Heat Energy Formula' that is, (mass) * (Sp. heat of material)

*(Temp. Difference) for calculating the heat energy & ultimately the time? Will it be the proper way of estimation for heat energy calculation? Should I assume the same sp.heat for entire range (that is, from ambient temperature to melting temperature of metals)? If anybody conclude something upon this please convey me.
• posted

Dude, would it be suffient to figure arc heat input as 70% x Amps x Volts x Seconds = Joules, and the hot wire heat input as Amps x Volts x Seconds = Joules?

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