Hardness of Mod.9Cr-1Mo tube at elevated temperature

Furukawa, Tomohiro  ; Yoshida, Eiichi

High temperature hardness measurement for the steam generator tube made of Mod.9Cr-1Mo has been performed in the temperature range from R.T. to 1200C in inert gas and in vacuum, as one of the basic experiments for the establishment of the mechanism analysis of sodium - water reaction. The major results are as follows. (1) The hardness of the material was decreased with the increasing of the testing temperature. In the temperature range of 800 to 900C, stagnation of the value caused by Alfa - phase transformation was observed, and then the value was decreased with the increasing of the temperature again. The effect of examination atmosphere was not observed under this research. (2) Good correlation between hardness and tensile strength was observed in the temperature range from R.T. to 1200C. (3) It is considered that the knowledge about the strength of the steam generator tube in high temperature can be reflected as base data to the solution of a wastage mechanism.