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Indexed by:Journal Papers

Date of Publication:2019-11-01

Journal:JOURNAL OF SHIP PRODUCTION AND DESIGN

Included Journals:EI、SCIE

Volume:35

Issue:4

Page Number:338-343

ISSN No.:2158-2866

Key Words:hot cracking; Invar alloy; laser welding; cooling rate

Abstract:Hot cracking is one of the major challenges in laser welding of Invar alloy. In this study, welding hot cracking susceptibility experiments are conducted with fish-bone-type Invar alloy sheets under pulsed laser welding condition. The pulse wave consists of two distinct power levels: welding pulse and post-heating pulse. The welding temperature field can be controlled by changing the duration of the post-heating pulse. The results of experimental measurements and finite element method calculation show that increasing of the post-heating pulse duration leads to a decline in the cooling rate of weld metal within the brittle temperature range, although the welding hot cracking susceptibility decreases at first and then increases. Neither the heat input nor the cooling rate is the only decisive factor for hot cracking during the welding process.