摘要
现代化交通运输是国家经济的命脉。制动盘是保证高速列车安全可靠运行的重要部件之一。但制动盘在高速运行中,面临苛刻的服役环境,容易出现磨损、裂纹等现象,造成制动盘失效。以24CrNiMo合金钢粉末为熔覆材料,通过改变激光熔覆的工艺参数,在钢板上制备单道和多层的熔覆层。利用体视显微镜、蔡司显微镜、SEM、显微硬度测试、拉伸试验等分析手段,分析比较工艺参数对单道成形的影响,以及对多层多道的熔覆层微观组织和力学性能的影响。结果表明:随着激光功率的增大,熔宽增大而余高减小;随着扫描速度增加,熔宽和余高都减小;随着送粉速度的增大,熔宽和余高都增加,但易出现气孔和裂纹;熔覆层表面为板条马氏体、针状铁素体及上贝氏体;近基体的微观组织由粗大的珠光体、铁素体和粒状贝氏体组成;扫描速度过大时,熔覆层的硬度变化波动大,且分布不均匀;拉伸断口呈韧窝状,当扫描速度为340 mm/min时,熔覆层的抗拉强度为1110.22 MPa,延伸率为10%,达到了传统铸钢件的标准。合理控制熔覆工艺参数,能够达到高硬度、高韧性等性能要求,实现高速列车制动盘高效增材制造。
Modern transportation is the lifeblood of national economy.The brake disc is one of the important parts to ensure the safe and reliable operation of high-speed train.However,the brake disc is at high speed,facing harsh service environment,prone to wear,crack,and other phenomena,resulting in the failure of the brake disc.In this experiment,24CrNiMo alloy steel powder was used as cladding material.By changing the process parameters of laser cladding,single-channel and multi-layer cladding layers were prepared on steel plates.By means of stereomicroscop,Zeiss microscope,SEM,microhardness test,and tensile test,the influences of process parameters on the single-pass forming and the microstructure and mechanical properties of multi-pass cladding layer were analyzed and compared.The results show that with the increase of laser power,the fusion width increases while the residual height decreases.With the increase of scanning speed,the fusion width and residual height both decrease.With the increase of powder feeding speed,the fusion width and residual height both increase,but pores and cracks are easy to appear.The surface of the cladding layer is lath martensite,acicular ferrite and upper bainite.The microstructures near the matrix are coarse pearlite,ferrite,and granular bainite.When the scanning speed is too high,the hardness of the cladding layer fluctuates greatly and the distribution is not uniform.When the scanning speed is 340 mm/min,the tensile strength of the cladded layer is 1110.22 MPa and the elongation is 10%,which reaches the standard of traditional steel casting.Reasonable control of cladding process parameters can achieve high hardness,high toughness,and other performance requirements,and can realize efficient additive manufacturing of brake discs for high-speed trains.
作者
温飞娟
陶诗美
龙樟
陈辉
吕航
陈勇
Wen Feijuan;Tao Shimei;Long Zhang;Chen Hui;Lu Hang;Chen Yong(School of Engineering,Southwest Petroleum University,Nanchong 63700,Sichuan,China;School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,Sichuan,China)
出处
《应用激光》
CSCD
北大核心
2023年第8期18-31,共14页
Applied Laser
基金
南充市-西南石油大学市校科技战略合作专项(SXQHJH034,SXQHJH027)
四川省2021-2023年高等教育人才培养质量和教学改革项目(JG2021-639)
教育部2021年第一批产学合作协同育人项目(202101398047,202102500012)。
