초록 ▼

There is provided a nuclear fuel element having a zirconium alloy cladding tube with improved corrosion resistance. The cladding tube comprises a metallurgical gradient across the width of the tube wall wherein the tube has a more corrosion-resistant metallurgical condition at the outer circumferenc

There is provided a nuclear fuel element having a zirconium alloy cladding tube with improved corrosion resistance. The cladding tube comprises a metallurgical gradient across the width of the tube wall wherein the tube has a more corrosion-resistant metallurgical condition at the outer circumference and a less corrosion-resistant metallurgical condition at the inner circumference. The metallurgical gradient can be generated by heating an outer circumferential portion of the tube to the high alpha or mixed alpha plus beta range while maintaining the inner surface at a lower temperature, followed by cooling of the tube.

대표청구항 ▼

A process for producing a zirconuim alloy tube having a metallurgical gradient having a less corrosion-resistant metallurgical condition at the inner circumference of the tube and a more corrosion-resistant metallurgical condition at the outer circumference of the tube comprising: forming a zirconiu

A process for producing a zirconuim alloy tube having a metallurgical gradient having a less corrosion-resistant metallurgical condition at the inner circumference of the tube and a more corrosion-resistant metallurgical condition at the outer circumference of the tube comprising: forming a zirconium alloy tube having said less corrosion-resistant metallurgical condition; heating an outer circumferential portion of the tube to the high alpha range, or mixed alpha plus beta range for a time sufficient to transform the outer circumferential portion of the tube to said more corrosion-resistant metallurgical condition while cooling to maintain the inner circumferential portion of the tube at a temperature sufficiently low that essentially no metallurgical change occurs at the inner surface; cooling the tube sufficiently rapidly to retain said more corrosion-resistant metallurgical condition at the outer circumference portion; and reducing the diameter of the thus heat treated tube with multiple cold working reduction passes in a reduction mill.