闭塞锻造中预涂石墨的作用  

Effect of pre-coating graphite in closed-die forging

作　　者：杨程[1] 陈璇 张金虎 庄晓伟 王玲 章建军 Yang Cheng;Chen Xuan;Zhang Jinhu;Zhuang Xiaowei;Wang Ling;Zhang Jianjun(School of Metallurgical Engineering,Xi′an University of Architecture and Technology,Xi′an 710055,China;Jiangsu Longcheng Precision Forging Group Co.,Ltd.,Changzhou 213164,China)

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055 [2]江苏龙城精锻集团有限公司,江苏常州213164

出　　处：《锻压技术》2023年第4期1-7,共7页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51874226);陕西省重点研发计划项目(2018ZDXM-GY-120)。

摘　　要：为了确定闭塞锻造中预涂石墨的作用,采用热重分析仪STA449F3、高温箱式电阻加热炉DWRX-54-12、UMT-3高温摩擦磨损试验机和扫描电子显微镜SEM研究了石墨在高温下对坯料表面的氧化防护作用和对模具表面的润滑作用。结果表明:石墨在加热温度为1000℃下保温80 s后的烧损率为55%,温度高于1000℃时烧损率大幅增加;在温度为1000、1050、1100和1200℃时无预涂石墨的试样表面烧损严重,烧损质量随着温度的升高从36.7 mg增大至72.6 mg;在1000和1100℃时预涂石墨层对试样表面的保护效果良好,在1200℃时石墨层烧损严重,试样表面出现氧化增重现象;预涂石墨后,H13钢表面磨损区域的氧化物颗粒随着温度的升高逐渐增多,摩擦因数在温度为400、500和600℃下分别稳定在0.05~0.07、0.33~0.37、0.36~0.38之间。因此,高温下对坯料和模具表面预涂石墨可以起到良好的氧化防护和润滑效果。In order to determine the effect of pre-coating graphite in closed-die forging,the oxidation protection effect of graphite on the surface of blank and the lubrication effect on the surface of die at high temperature were studied by thermal gravimetric analyzer STA449F3,high-temperature box resistance heating furnace DWRX-54-12,UMT-3 high-temperature friction and wear testing machine and scanning electron microscope SEM.The results show that the burning loss rate of graphite after heating at 1000℃for 80 s is 55%,and the burning loss rate increases significantly when the temperature is higher than 1000℃.When the temperature is 1000,1050,1100 and 1200℃,the surface of sample without pre-coating graphite is seriously burned,and the burning mass increases from 36.7 mg to 72.6 mg with the increasing of temperature.However,when the pre-coating graphite layer is at 1000℃and 1100℃,the surface protection effect of sample is good.At 1200℃,the graphite layer is seriously burned,and the oxidizing weight gain occurs on the surface of sample.After pre-coating graphite,the oxide particles in the wear area of H13 steel surface gradually increase with the increasing of temperature,and the friction coefficient is stablely between 0.05-0.07,0.33-0.37 and 0.36-0.38 at 400,500 and 600℃,respectively.Therefore,pre-coating graphite on the surface of sample and die at high temperature can have good oxidation protection and lubrication effect.

关 键 词：闭塞锻造 预涂石墨 氧化保护 润滑 摩擦因数 

分 类 号：TG316[金属学及工艺—金属压力加工]