Corrosion and Compatibility in

Advanced Reactor Systems

ENVIRONMENT CANDIDATE MATERIALS

liquid metals Na iron based alloys Pb-Bi iron based

helium/graphite Ni based alloys

supercritical water Fe,Ni,Ti,Zr, based alloys stress corrosion cracking

molten salt

Hugh IsaacsBNL

isaacs@bnl.gov

liquid metal compatibility

solubility in liquid metal construction alloys interstitials O, C, N, H

solid surfaces

extraction insertion

products

mass transport gradients in liquid activity in solids reaction

Na

Na

Na/Na2O

Pb/PbO

Ellingham-Richardson-Diagram

Pb/Pb-Bi

corrosion inhibition of ferritic steels by 50-500 ppm Zr, Ti forms nitrides or nitrides+carbides on steel surfaces

6000 h CrMoV steel

300–500 ppm Mg

300 h 2CrSiMoV steel

300–500 ppm Mg + 10-40 ppm Ti

600 C

oxygen concentration effects on steels

flowing Pb 550C 3000 h

Pb/Pb-Bi

Pb15Cr–11Ni–3Si–MoNb

low oxygen550C 2000 h

Groynin (1998)

controlled oxygen

He1000C 1000h

oxidizing conditions reducing conditions

Inconel 617

Hynes 230

Wright 2008

Wright 2008Quadakkers 1988

stronglyreducing

highly oxidizing

highly carburizing

bestregion

carburizing under oxide

“thermodynamic” representation of alloy behavior

He

Supercritical water

Ferritic–martensitic Austenitic Ni-based

weight gain largest weight gain < ferritic-m little weight gainthan ferritic–martensitic complex parametrics except below the pseudo-criticalCr reduces rate good grain boundary eng. precipitate hardened pitlowest rates at 300 ppb Oimplant Y - major improvement

Zirconium Titanium

std alloys corrode optimized comps ~ austeniticoptimized comp > austenitics

alloy systems under study

Was et al. (2007)

Stress Corrosion Cracking

Supercritical water

austenitic IGSCC > ferritic-martensitic

acidic additions increase cracking

higher Cr increases susceptibility to HCl

increased pressure increases SCC

ferritic -m in pure systems resistant to 600 C

Temperature 0-3000 K

-2 -1 log pCO=0 +1 +2