オーステナイト系ステンレス鋼ろう付け材の引張強度特性に及ぼす水素の影響

抄録

The objective of this study was to ensure the safety use of brazing parts of Coriolis flowmeter in high-pressure hydrogen gas. Thermal desorption analysis measured that the hydrogen diffusion coefficient of brazing filler metal, Ni-30Cr-4Si- 6P, was one third as small as that of the material of brazed pipe; austenitic stainless steel, XM-19 (HRX19). In order to investigate the effects of hydrogen on the strength of brazed parts, four types of tensile tests using brazed specimen were conducted as follows: (i) test of non-charged specimen in air, (ii) test of non-charged specimen in 0.7-MPa hydrogen gas, (iii) test of non-charged specimen in 95-MPa hydrogen gas, and (iv) test of hydrogen-charged specimen in air. The fracture was occurred from the brazing parts in all the cases, and the tensile strengths obtained were nearly the same in all the cases, i.e. the tensile strength was not degraded due to hydrogen.