摘要
利用激光合金化技术在45钢表面制备了碳合金化层,借助OM、XRD和显微硬度计等研究了最佳工艺下合金化层的组织和性能,并与利用传统气体渗碳技术制备渗碳层的结果进行了对比。结果表明:影响合金化层硬度的主次顺序为激光功率>搭接率>扫描速度;随着激光功率、扫描速度、搭接率的增大,合金化层的硬度均呈先增后减的趋势;当激光功率为1.5 kW、扫描速度为500 mm/min、搭接率为40%时,合金化层硬度最高,其厚度为600μm,组织由针状马氏体、碳化物(M_(7)C_(3)、Fe_(3) C)以及少量残留奥氏体组成,平均硬度约为617 HV0.3,热影响区厚度为400μm,组织为马氏体以及残留奥氏体,平均硬度约为432 HV0.3,基体组织由铁素体和珠光体组成,硬度约为201 HV0.3;与传统气体渗碳工艺相比,激光碳合金化具有组织细小、高效、绿色环保等优势,是未来一个重要的发展方向。
Carbon alloyed layer was prepared on the surface of 45 steel by laser alloying process.The microstructure and properties of the alloyed layer under the optimal process were studied by means of OM,XRD and microhardness tester.The microstructure characteristics and efficiency of gas carburizing and laser carbon alloying were compared.The results show that the effect of each parameter on hardness of the alloyed layer is as follows:laser power>lap rate>scanning speed.With the increase of laser power,scanning speed and lap rate,the hardness of the alloyed layer increases first and then decreases.When the laser power is 1.5 kW,the scanning speed is 500 mm/min and the lap rate is 40%,the hardness of the alloyed layer is the highest,the thickness of alloyed layer is capable of reaching 600μm,the microstructure is composed of acicular martensite,carbide(M_(7)C_(3),Fe_(3) C)and a small amount of residual austenite,and the average hardness is about 617 HV0.3,the thickness of HAZ is 400μm,microstructure is composed of martensite and retained austenite,and the average hardness is about 432 HV0.3,the microstructure of matrix is composed of ferrite and pearlite,the hardness is about 201 HV0.3.Compared with the traditional gas carburizing process,laser carbon alloying has the advantages of fine structure,high efficiency,green and environmental protection.It is an important development direction in the future.
作者
李海涛
张蕾涛
夏慧芸
戴姣燕
徐金富
Li Haitao;Zhang Leitao;Xia Huiyun;Dai Jiaoyan;Xu Jinfu(School of Materials Science and Engineering,Chang'an University,Xi'an Shaanxi 710061,China;School of Materials and Chemical Engineering,Ningbo Institute of Engineering,Ningbo Zhejiang 315211,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2021年第10期237-241,共5页
Heat Treatment of Metals
基金
宁波市2025重大专项(2019B10084)。
关键词
激光合金化
正交试验
合金化层
渗碳
显微硬度
laser alloying
orthogonal experiment
alloyed layer
carburizing
microhardness
