鋼溶接熱影響部の結晶粒微細化に及ぼすTi及びNの複合添加の影響

抄録

Suppressive effects of Ti and N to the austenite grain growth in weld heat affected zone of steels were investigated from a standpoint of the time exponent, n and the activation energy for boundary migration, Q in isothermal grain growth test. The results obtained are as follows. 1) Austenite grain growth of steels added together both Ti and N can be expressed by Beck's equation. 2) Value of n is remarkably influenced by the quantity of a insoluble Ti (or N) and independent of a soluble Ti (or N). 3) Value of Q is increased considerably in duplex addition compared with separate addition of Ti and N. In this case an extent of the effect of a soluble Ti (or N) to Q is a greater than a insoluble Ti (or N). 4) Grain size of austenite isothermaly heated can be estimated using coefficient of austenite grain growth which is decided by quantity of Ti and N added in steels.