Response of stainless steels to plasma disruptions by simulation experiments with an intense hydrogen beam

The effect of crystal structures and chemical compositions of stainless steel on cracking and melting behavior under high heat fluxes was examined by using the Particle Beam Test Facility. Thirty different kinds of stainless steels were exposed to a single hydrogen beam with 92 MW/m2 heat flux and 100 ms pulse length. The resistance to evaporation and the threshold energy for melting dependend on the type of crystal structures and increasing with order of ferritic-, duplex, and austenitic-stainless steel. Ferritic and duplex stainless steels showed higher cracking resistance except for HT-9 with high carbon content for which cracks were observed only in the outer side of the resolidification layer. The cracking resistance of austenitic stainless steels decreased with increasing amounts of minor elements of P, Si and C. The limiting content of such elements in austenitic alloys for maintaining adequate cracking resistance was estimated to be P < 0.015, Si < 0.3 and C < 0.1 (in wt%). (orig.)