I NEED EFFECT OF INCREASING TIME IN QUALITY OF SPOT WELD AND TABLE FOR ADJUSTING THE PARAMETER AND WHAT IS THE TOLERANCE FOR USING THIS TABLE.

BEST REGARD

-- saeid babai (m_s_babai@yahoo.com), July 15, 2001

Answers

The Resistance Welding Manual Fourth Edition by the RWMA is an excellent reference source for resistance welding background. It may be purchased from any RWMA member.

The basic weld formula is shown below along with a comparative weld schedule formula. You will note that since heat import is equal to the square of the weld current time the weld heat time, a small change in weld current will effective the weld greater than a change in weld time.

Electrical Power in Watts = (Weld Current#1)2 times Time #1 (Weld Current#1)2 times Time #1 = (Weld Current#2)2 times Time #2

Increasing the weld time will normally grow the nugget larger in diameter as well as increase the depth of the weld nugget.

I would suggest, however, staying within plus or minus 10% of that shown in reference books, until one has a thorough understanding of each of the variable and their effects on the weld nugget quality.

Bob

-- Bob Balla (bobballa@tjsnow.com), July 23, 2001.