A critical analysis of weld heat input measurement through a water-cooled stationary anode calorimeter

Abstract

Comprehensive models of heat transfer require specification of the total amount of heat received by the workpiece. The objective of this work was to critically examine the use of a water-cooled stationary anode calorimeter to obtain both arc efficiency and total heat input into the workpiece. For simplicity and clarity, this last quantity is called the gross heat input. The effects of current, material type and water flow rate on the calorimeter performance were determined experimentally. Some measures for reducing errors in calorimetry were evaluated. Improvements were made to reduce heat losses from the top surface of the test coupon and boost heat removal from the opposite surface. A sensitivity test was conducted to estimate the effect of measurement inaccuracies. The results demonstrate the effectiveness of calorimetry for measuring gross heat input in arc welding.

Dependency of arc efficiency on welding current in gas metal arc welding

“…On the other hand, it is noted below that what should be ideal arc efficiency in this paper is different from that Hurtig et al mentioned 18) . They tried to measure heat input and arc efficiency before heat in the base metal is lost to environment or even thermal conduction from the base metal surface to inside occurs.…”

Effect of multipass TIG welding on the corrosion resistance and microstructure of a super duplex stainless steel

“…The voltage, current, and welding speed were 145.1 A, 13.0 V, and 4 mm/s for the low heat input (LHI) and 145.5 A, 14.7 V, and 2 mm/s for the high heat input (HHI), respectively. Considering the arc efficiency of 0.81 for the TIG process , low and high heat inputs are 0.37 and 0.87 kJ/mm, respectively.…”

Welding thermal stress diagrams as a means of assessing material proneness to residual stresses

“…The procedure applied to determine these actual welding thermal cycles is summarized as follows (more details can be found at Mishchenko [20]): [21]) multiplied by a thermal efficiency factor (g t ). However, intrinsic errors and difficulties to measure thermal efficiency have been demonstrated by Liskevych and Scotti [22] and Hurtig et al [23]. For this reason, and considering the use of resultant actual weld cross sections, in this work the heat input-related input parameter used in Rosenthal's equations is replaced by arc energy (q/v); (d) With the input parameters, the heating and cooling times and peak temperature profiles are traced for each desirable condition; (e) In order to facilitate script programming on Gleeble, the thermal cycle generated is discretized in linear stretches, as illustrated in Fig.…”