Annealing cracking in Zr and a Zr-alloy with low hydrogen concentration  

作　　者：Xi-Heng Lin Irene J.Beyerlein Wei-Zhong Han 

机构地区：[1]Center for Advancing Materials Performance from the Nanoscale,State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an 710049,China [2]Materials Department,University of California,Santa Barbara,CA 93106-5070,USA [3]Department of Mechanical Engineering,University of California,Santa Barbara,CA 93106-5070,USA

出　　处：《Journal of Materials Science & Technology》2024年第15期165-175,共11页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.51922082 and 51971170);the 111 Project of China(Grant Number 2.0,BP0618008).

摘　　要：Hydrogen embrittlement,also known as hydrogen-induced cracking,is a longstanding concern for zirco-nium(Zr)and its alloys.The affinity for hydrogen in zirconium results in the formation of brittle hydrides.Hydrides are conventionally thought to facilitate crack propagation,and the prevailing recommendation to hinder hydride embrittlement involves reducing the hydrogen concentration in the material and ap-plying slow cooling to reduce thermal stresses.Here,in Zr with a maximum hydrogen concentration of 43 wppm,we show that cracks initiate unexpectedly after annealing,a step that involves slow cooling and no external stress.With a suite of high-resolution microscopy,we show that annealing cracks initiate at prismaticδ-hydrides,whose presence is unexpected.The microscopic annealing crack paths are conse-quently crystallographic,following the habit plane of these prismaticδ-hydrides.The commonly reportedγ-hydride andδ-hydrides that develop on the basal plane are found not to initiate cracks.We rationalize that prismaticδhydrides result from the intergranular thermal residual stresses that develop during slow cooling.This finding of uncommon annealing cracking further advances the mechanistic understanding of hydride embrittlement in zirconium and can lead to new strategies for design and fabrication of advanced zirconium alloys for harsh environments.

关 键 词：ZIRCONIUM HYDRIDE CRACKING Habit plane REORIENTATION 

分 类 号：TG139.8[一般工业技术—材料科学与工程]