TWI Industrial Member Report Summary 198/1982
By P J Blakeley
Background
The thermal behaviour of a range of electron-beam (EB) welds in carbon-manganese and low alloy steels was investigated using a series of thermocouple recordings. Two different welding conditions were used for 11.5mm steel and two more for 48mm steel. One condition was used for 150mm steel.
Thermocouple data was used to construct sets of isotherms for each welding condition and to determine the fusion zone cooling times for the ranges 800 to 500°C and 800 to 300°C. A novel technique was used to determine the heat content of the welds which took into account all sources of EB energy losses during the welding process.
The experimentally measured temperature profiles nnd thermal cycles were then compared with values predicted by the Rosenthal 2D heat flow equation. Two models based on this theory, were examined and produced temperature cycles within 40-50°C of the measured values. Sufficient informntion is provided to enable the thermal behaviour of any EB weld in steel to be predicted. This information could then be used to assist in the estimation of the metallurgical properties likely to result from specific welding parameters.