摘要
采用激光熔覆技术和35Cr2Ni4MoA粉末,在锻造退火的35Cr2Ni4MoA基体上制备熔覆层。通过观察分析不同激光熔覆工艺参数下单道熔覆层的宏观形貌及截面形貌,研究了激光熔覆关键工艺参数对35Cr2Ni4MoA熔覆层组织形貌的影响规律,发现送粉速率对熔覆层宽高比的影响最大。之后研究了这3种热处理方式对熔覆试样组织和性能的影响,详细对比了低温热处理、回火、淬火和回火这3种热处理状态下基体、熔覆层和热影响区的的微观形貌、组织结构、拉伸性能、硬度和冲击韧性。低温热处理后,基体的组织为退火态的铁素体和珠光体,热影响区组织为铁素体和马氏体,熔覆层组织为马氏体,该热处理不改变组织,对性能有微小的影响。只进行回火时,热影响区和熔覆层中的马氏体转变为回火索氏体,使熔覆层硬度降低,冲击韧性提高。进行淬火和回火时,熔覆层和基体的组织结构均转变为回火索氏体,此时抗拉强度最大,但冲击韧性最小,低于退火态基体。
Laser cladding technology and 35Cr2Ni4MoA powder were used to prepare the cladding layer on the forged and annealed 35Cr2Ni4MoA substrate.By observing and analyzing the macroscopic morphology and cross-sectional morphology of the single-pass cladding layer under different laser cladding process parameters,the influence of key laser cladding process parameters on the microstructure and morphology of the 35Cr2Ni4MoA cladding layer was studied,and it is found that the powder feeding speed has the greatest impact on the width to height ratio of the cladding layer.Then,the effects of the three heat treatment methods of low temperature heat treatment,tempering,quenching and tempering on the microstructure and properties of the cladding samples were studied.The micromorphology,microstructure,tensile strength,hardness and impact toughness of the matrix,cladding layer and heat-affected zone under the three heat treatment conditions were compared in detail.After low-temperature heat treatment,the structure of the matrix is annealed ferrite and pearlite,the structure of the heat-affected zone is ferrite and martensite,and the structure of the cladding layer is martensite.The heat treatment does not change the structure and has a tiny impact on the performance.When only tempering is performed,the martensite in the heat-affected zone and the cladding layer transforms into tempered sorbite,which reduces the hardness of the cladding layer and improves the impact toughness.When quenching and tempering are performed,the microstructure of the cladding layer and the matrix transforms into tempered sorbite.At this time,the tensile strength is the maximum,but the impact toughness is the minimum,which is lower than that of the tempered matrix.
作者
李威
周俊
赵文
许世明
葛海锋
林开章
LI Wei;ZHOU Jun;ZHAO Wen;XU Shiming;GE Haifeng;LIN Kaizhang(Chengdu State-owned Jinjiang Machinery Factory,Chengdu 610041,China)
出处
《热加工工艺》
北大核心
2026年第3期100-108,118,共10页
Hot Working Technology
基金
国家重点研发计划项目(2024YEC3908100,2024YEC3908103)。
