Abstract
Fundamental researches upon the deterioration of mechanical strength owing to the graphitization in weld heat-affected zone has been done, and reported in this paper.
Theorical foundation and experimental verification are as follows;
1) The following reaction was confirmed from the result of the magnetic research of quenched carbon steel during tempering.
2Fe2C→Fe3C+Fe+C
2) The fact that weld heat-affected zone preferentially graphitized was theoretically explained from above-mentioned reaction.
3) The formation of chain graphite was confirmed and its forming mechanism was explained in detail.
