低炭素鋼の電弧熔接に於ける熱影響に関する基本的研究(第1報)

抄録

In the welding procedure, the regulation of welding heat is primary importance of securing the good quality of weld. The maximum temperature of metal heated by welding heat and heating. and cooling rate of it are serious factors to consider on the physical and chemical properties of various part of welded bodies.
The author has studied to determine the temperature distribution caused by welding heat in low carbon steel. As the problem of heat conduction, arc welding is supposed to be the problem of moving heat source .in constant speed. This solution is very difficult. In order to simplify the solution, the author assumes that the heat is instantaneosly supplied on the weld part and that heat conductivity, density and specific heat of material are constant and that the material is infinite solid body at zero temperature when time t=0 and radiation does not take place at the surface of it.
We know that the differential equation of heat conduction is shown as follow :
∂θ/∂t=k∇^2θ
θ=temperature t=time k=constant (Thermometric conductivity)
For instantaneous source, the solution of the above equation is given. In order to obtain the approximate value of temperature at any point situated in the adjacent part of weld, summation of heat due to each instantaneous source that is assumed to independently satisfy the above equation is applied
From calculation, temperature distributions are given for thick plate and thin plate. Diagrams in respect to the temperature distribution are shown as follows:
1. Temperature-time curve at various position refer to instantaneous heat source (Figure 6-18)
2. Temperature time-curve at various position refer to moving heat Source (Figure 19-54)
3. Cooling curve in the case of suspension of welding (Figure 55-62)
4. The maximum temperature distribution diagram (Figure 63-63)
5. Equi-temperature line (Figure 69-81)
6. Temperature distribution on the surface perpendicular to weld line (Figure 82-84)
7. Effect of thermometric conductivity (k)(Figure 85-92)