Development of a Co-free, Ni-based alloy layer (Ni-SD) for sealing surfaces of nuclear-power valves cladding by hollow laser beam. (April 2015)

• Record Type: Journal Article
• Authors: Shi, T.; Fu, G. Y.; Xu, A. Q.; Lu, B. H.
• Is Part Of: Materials research innovations. Volume 19(2015)Supplement 1
• Page Start: S1-83
• Page End: S1-88
• Publication Date: 2015-04
• Subjects: Nuclear-power valves -- Co-free alloy -- Laser cladding -- Hollow laser beam -- Strengthening; Materials -- Research -- Periodicals; Matériaux -- Recherche -- Périodiques; 620.1105
• DOI: 10.1179/1432891715Z.0000000001374
• Languages: English
• ISSNs: 1432-8917

Abstract

Abstract : To avoid the activated radiation of elemental cobalt and meet the requirements of critical working conditions in which operate the sealing surface of nuclear-power valves, a new cobalt-free Ni-based alloy (Ni-SD) was developed. The powder was deposited on a stainless-steel substrate by a novel hollow laser beam cladding technique. The experimental results reveal that the micro-hardness of Ni-SD can approach 700 HV0·3, which is much higher than that of the common Co-based alloy Stellite6 (500 HV0·3 ) that is currently used in nuclear-power valves. Analytical results indicate that γ -Ni is the primary phase in the Ni-SD coating and that it proportionally dissolves metallic and non-metallic elements. In addition, the Ni-SD coating contains some hard phases, such as carbides and borides. High-temperature measurements indicate that the Ni-SD alloy offers excellent advantages such as high wear resistance and high-temperature operation.