二氧化铈对熔敷金属氢致塑性损失的影响及其机理研究  

Effect of Cerium Dioxide on Plastic Loss Caused by Hydrogen in Deposited Metal and Its Mechanism

作　　者：利成宁 王敬松 戴联双 王策 崔绍华 邸新杰[1,2] Li Chengning;Wang Jingsong;Dai Lianshuang;Wang Ce;Cui Shaohua;Di Xinjie(School of Materials Science and Engineering,Tianjin University,Tianjin 300350,China;Tianjin Key Laboratory of Advanced Joining Technology,Tianjin 300350,China;China Oil&Gas Piping Network Corporation,Beijing 100020,China)

机构地区：[1]天津大学材料科学与工程学院,天津300350 [2]天津市现代连接技术重点实验室,天津300350 [3]国家石油天然气管网集团有限公司,北京100020

出　　处：《天津大学学报（自然科学与工程技术版）》2024年第10期1062-1069,共8页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(52274391);国家管网集团重大科技专项项目(WZXGL202105).

摘　　要：针对X80管线钢,设计了金属粉型药芯焊丝的药粉成分,在金属粉中加入了二氧化铈,进行熔敷金属堆焊试验和电化学充氢后的拉伸试验,研究焊材中加入二氧化铈对熔敷金属抗氢脆性能的影响,同时通过氢渗透试验研究了二氧化铈的添加对氢在熔敷金属中扩散的影响.结果表明,熔敷金属的显微组织主要由针状铁素体和晶界铁素体构成.二氧化铈的添加对熔敷金属的夹杂物有显著影响,导致其平均尺寸减小、数量密度增加.加入2%的二氧化铈后,夹杂物的平均尺寸由0.349μm减小至0.258μm,夹杂物数量密度由21429mm^(-2)增加至32254mm^(-2).氢渗透试验结果表明,添加二氧化铈可增加熔敷金属的氢陷阱数目,阻碍氢在熔敷金属中的扩散,这导致熔敷金属抗氢脆性能的提升.因此,熔敷金属的氢致塑性损失率由72%降低至50%.对于充氢拉伸断口形貌,未加入二氧化铈的断口为河流花样的准解理断裂样貌,属于典型的脆性断裂特征.加入二氧化铈的断口有大量韧窝,具有韧性断口特征,但出现明显的鱼眼区.鱼眼区内的源区存在夹杂物或气孔,放射区则呈现准解理断裂.For X80 pipeline steel,the powder composition of metal powder flux-cored welding wire was designed,and cerium dioxide was added to the metal powder.The welding of deposited metal and the tensile test after electrochemical hydrogen charging were performed.The effect of cerium dioxide on the hydrogen embrittlement resistance of deposited metal was studied.Furthermore,the influencing mechanism of cerium dioxide on the diffusion of hydro-gen was discussed based on a hydrogen permeation test.The results showed that the microstructure of the deposited metal was mainly composed of acicular ferrite and grain boundary ferrite.The addition of cerium oxide had significant effect on the inclusions of the deposited metal,leading to the decrease in the average size and increase in the number density.When 2%cerium dioxide was added,the average size of inclusions decreased from 0.349μm to 0.258μm,and the number density of inclusions increased from 21429 mm^(-2)to 32254 mm^(-2).The results of hydrogen permeation test showed that the addition of cerium dioxide increased the number of hydrogen traps and inhibited the diffusion of hydrogen in the deposited metal,which led to the improvement of the hydrogen embrittlement resistance of the deposited metal.Therefore,the plastic loss rate induced by hydrogen decreased from 72%to 50%.In terms of hydrogen charging tensile fracture morphology,the fracture without adding cerium dioxide were the quasi-cleavage fracture appearance of river pattern,which were the typical brittle fracture characteristics.The fracture with the addition of cerium dioxide had a large number of dimples,which was a typical ductile fracture feature.However,there was an obvious fisheye region.In the fisheye region,the source region had inclusions or pores,and the radial region showed quasi-cleavage fracture.

关 键 词：氢脆 熔敷金属 二氧化铈 氢扩散 

分 类 号：TG424[金属学及工艺—焊接]