氮氢比对H13钢离子渗氮组织和耐磨性能的影响
Effect of Ratio of Nitrogen to Hydrogen on Microstructure and Wear Properties of Plasma Nitrided H13 Steel
高玉新 1王均波 1程虎2
作者信息
- 1. 日照职业技术学院机电工程系,山东 日照 276826
- 2. 浙江省工量刃具检测与深加工技术研究重点实验室,浙江 台州 318000
- 折叠
摘要
针对H13钢离子渗氮精密热锻模具出现早期疲劳裂纹或龟裂问题,开展温度520℃、气压250 Pa、不同氮氢比条件下的离子渗氮试验,以考察渗氮气氛中氮氢比对渗层组织及耐磨性能的影响规律.利用X射线衍射仪、共聚焦显微镜、扫描电镜、显微硬度计和摩擦磨损试验机分析不同氮氢比渗氮后渗层的相结构、显微组织、显微硬度及耐磨性能.结果表明:渗氮时间3 h、氮氢比为1∶3、1∶4、1∶5时,渗层物相主要由ε-Fe2-3 N、γ'-Fe4 N、αN-Fe(N)相组成,氮氢比为1∶8时渗层物相主要为γ'和αN相;渗层深度及硬度随渗氮气氛中氮浓度降低而减小,氮氢比为1∶8时,延长渗氮时间可增加渗层厚度,在60μm渗层深度内硬度可达800～900 HV0.1.氮氢比为1∶3、1∶4的渗层的磨损机理以疲劳磨损为主;氮氢比为1∶5、1∶8的渗层的磨损机理以磨粒磨损为主.采用氮氢比为1∶8对H13钢进行离子渗氮,渗层中无化合物层和脉状组织,渗层可获得适中的硬度和较佳的韧性,具有较好的耐磨性能.
Abstract
Aiming at the problem of early fatigue cracks in plasma nitrided H13 steel precision hot forging dies,plasma nitriding process tests were conducted under a nitriding temperature of 520 ℃,a pressure of 250 Pa and different nitrogen to hydrogen ratio conditions to reveal the effect of nitrogen hydrogen ratio in a nitriding atmosphere on the microstructure and wear properties of coating.The phase structures,micro-structure,microhardness and wear properties of the nitrided coatings with different nitrogen hydrogen ratios were examined and analyzed using X-ray diffraction(XRD),confocal microscopy,scanning electron microscopy(SEM),microhardness tester and a friction and wear test ma-chine.Results showed that the nitrided coatings with N∶H=1∶3,1∶4 and 1∶5 after 3 h mainly consisted of ε-Fe2-3 N,γ'-Fe4 N and αN-Fe(N) phases,respectively,while nitrided coatings with N∶H=1∶8 mainly consisted of γ' and αN .The depth and hardness of the nitri-ded layers decreased with the reduction of N concentration in the nitriding atmosphere.The depth of the nitrided layer with N∶H=1∶8 in-creased with nitriding time,and the hardness reached 800～900 HV0.1 at a depth of 60μm.The wear mechanisms were mainly fatigue wear for the nitrided coatings with N∶H=1∶3,1∶4,and abrasive wear for the coatings with N∶H=1∶5,1∶8.When ion nitriding H13 steel with a nitrogen to hydrogen ratio of 1∶8 was carried out,there was no compound layer or vein like structure in the nitriding layer,and the nitriding layer could obtain moderate hardness and better toughness,with good wear resistance.
关键词
H13钢/离子渗氮/氮氢比/微观组织/耐磨性能Key words
H13 steel/plasma nitriding/ratio of nitrogen to hydrogen/microstructure/wear resistance引用本文复制引用
基金项目
日照职业技术学院校企研究课题(2022H16)
台州市科技计划项目(2002gy10)
出版年
2024
NETL
NSTL
万方数据