Lingyun XU
,
Xiaochun WU
,
Hongbin WANG
材料科学技术（英）
In order to lower the boriding temperature of hot work steel H13, method of surface mechanical attrition treatment (SMAT), which can make the grain size of the surface reach nano-scale, was used before pack boriding. The growth of the boride layer was studied in a function of boriding temperature and time. By TEM (transmission electron microscopy), SEM (scanning electron microscopy), XRD (x-ray diffraction) and microhardness tests, the grain size, thermal stability of the nano-structured (NS) surface and the thickness, appearance, phases of the surface boride layer were studied. Kinetic of boriding was compared between untreated samples and treated samples. Results showed that after SMAT, the boride layer was thicker and the hardness gradient was smoother. Furthermore, after boriding at a low temperature of 700℃ for 8 h, a boride layer of about 5 μm formed on the NS surface. This layer was toothlike and wedged into the substrate, which made the surface layer combine well with the substrate. The phase of the boride layer was Fe2B. Research on boriding kinetics indicated that the activation energy was decreased for the treated samples.
关键词:
Boriding
,
表面机械研磨处理
,
H13钢
,
渗硼动力学
Xinbin HU
,
Mei ZHANG
,
Xiaochun WU
,
Lin LI
材料科学技术（英）
Based on the local equilibrium assumption, coarsening behavior of M23C6 carbide at 700℃ in H13 steel was simulated by DICTRA software. The results from the calculations were compared with transmission electron microscopy (TEM) observations. The results show the interfacial energy for M23C6 in H13 steel at 700℃ is thus probably 0.7 J•m-2, which fits the experiments well. The influence of composition and temperature on the coarsening rate was also investigated by simulations. Simulations show a decrease in the coarsening rate when V/Mo ratio is increased, while the coarsening rate increases with increasing temperature.
关键词:
DICTRA Simulation
,
碳化物粗化
,
界面能
,
H13钢
伍翠兰
,
罗承萍
,
陈振华
,
邹敢峰
材料热处理学报
doi:10.3969/j.issn.1009-6264.2007.03.022
应用扫描电镜(SEM)、微区成份分析(EDS)和X射线衍射研究了H13钢经离子渗氮后不同温度盐浴渗铬所得复合渗铬层的显微组织及其形成机制,并从热力学上探讨复合盐浴渗铬的可行性.H13钢复合渗铬化合物层为高铬化合物层,其相结构主要为CrN、(Cr,Fe)2N1-x和α-(Cr,Fe)组成;随渗铬温度的升高,复合渗铬试样表面上CrN和α相含量降低,而(Cr,Fe)2N1-x含量却增加并出现(Cr,Fe)2N1-x(0002)晶面择优取向,同时化合物层中出现氮浓度外低内高的层状结构.
关键词:
H13钢
,
复合渗铬
,
氮化铬
,
热力学
朱瑞华
,
田林海
,
鲍明东
,
马永
,
唐宾
机械工程材料
采用等离子氮化技术对H13钢进行离子氮化，通过改变渗氮气压和温度得到不同成分和厚度的渗氮层。用光学显微镜和X射线衍射仪分析了渗层的组织及物相组成，借助球一盘磨损试验机对渗层在大气环境下与Al2O3。球对磨时的摩擦学性能进行了研究。结果表明：渗层主要由ε-Fe2-3N、γ＇-Fe，N和少量α-Fe、Fe2O3、Fe2O4相构成；渗氮温度为510℃时没有形成明显的渗层，渗氮温度为570℃、气压为200，300Pa和渗氮温度为540C、气压为100Pa时渗层只有扩散层，而在其他条件下渗层由白亮层和扩散层组成；氮化后表面硬度为1100～1200HV，较基体增加1倍左右；在温度为570℃、气压200Pa制备渗层的摩擦因数比基体大幅度降低，磨痕宽度变窄，比磨损率明显降低，耐磨性明显改善。
关键词:
离子氮化
,
H13钢
,
白亮层
,
耐磨性能
于忠江
,
王殿梁
,
刘杨
,
郝士明
,
赵刚
材料与冶金学报
doi:10.3969/j.issn.1671-6620.2002.04.015
对H13钢的CDC处理进行了研究,用金相显微镜及扫描电子显微镜分析了渗碳层的组织形貌,用X射线衍射分析了碳化物的组成.确定了H13钢在950℃CDC处理的最佳碳势为w[C]=1.2%;可获得经水淬后的渗层组织为马氏体基体上弥散分布的碳化物,主要碳化物是颗粒平均尺寸为250 nm的Cr7C3,渗层厚度达到550 μm,最高硬度达到1250 Hm.与氮化处理的H13钢模具做了耐磨性比较,其耐磨性能优于氮化处理.
关键词:
H13钢
,
CDC处理
,
碳势
,
硬度
,
耐磨性
王冠
,
鞠慧
,
李落星
,
姚再起
机械工程材料
采用正交试验法设计气体渗氮试验,综合分析了渗氮前回火温度、渗氮温度、渗氮时间、氨分解率四个工艺参数对H13钢渗氮层深度及显微硬度的影响,得到了优化的渗氮工艺,并与优化前的工艺进行对比.结果表明:渗氮温度对渗层硬度的影响最为显著,随渗氮温度的升高,表面硬度先增加后降低；氨分解率对渗层深度影响最为显著,随着氨分解率的增大,渗层深度先减小后增大；最佳渗氮工艺为渗氮前560℃回火、渗氮温度535℃、渗氮时间15 h、氨气分解率50％；与原始工艺相比,优化后的渗氮工艺制备的渗氮层具有更大的渗层深度和硬度.
关键词:
H13钢
,
气体渗氮
,
正交试验
,
工艺参数
隗功益
表面技术
doi:10.3969/j.issn.1001-3660.2007.06.027
H13钢由于具有较高的淬透性和淬硬性,是1种重要的工业用钢,主要用于制造各种热作模具.热作模具在使用过程中,由于表面受到各种物理、化学等作用,其使用寿命较低.着重介绍了几种有利于提高H13钢模具寿命的表面改性技术.可以认为:多元共渗、复合处理及等离子体源离子注入技术均是改善H13钢模具表面性能的有效方法,而激光表面改性技术由于工艺过程中影响因素太多,设备费用昂贵,处理工件形状简单,其应用受到一定限制.
关键词:
H13钢
,
渗扩处理
,
离子注入
,
复合处理
,
激光表面改性
徐永礼
,
庞祖高
,
马宽猷
,
韦曼云
,
黄银燕
表面技术
利用扫描电镜、X射线衍射分析技术,对比经过RE-N-C-S-V-Nb多元共渗处理、气体渗氮处理和淬火+回火处理的H13钢三种试样的热疲劳性能,依据裂纹特征、裂纹结构,证明RE-N-C-S-V-Nb多元共渗H13钢具有较强的抗热疲劳性能.研究了多元共渗钒铌碳氮化物的细晶强化作用和位错强化作用,及其对钢热稳定性、高温硬度和抗氧化性的影响,从理论上揭示了RE-N-C-S-V-Nb多元共渗对热疲劳性能的强化机制.
关键词:
H13钢
,
多元共渗
,
热疲劳性
,
热稳定性
,
抗氧化性
