稀土催渗软氮化工艺研究

在常规气体氮碳共渗（软氮化）基础上加入不同量的自制稀土渗剂，研究稀土元素对软氮化过程的催渗作用，确定了稀土催渗软氮化工艺。试验结果表明：适量的稀土加入，具有明显的催渗作用，稀土催渗软氮化２小时的渗层性能可达到或超过常规软氮化５小时渗层性能。该工艺已应用于生产中，提高生产率，降低成本，取得显著的经济效益。     

M2钢软氮化脆性分析

本文对高速钢M2软氮化后的脆性试样渗层进行了电子探针扫描分析,发现软氮化渗层中引起脆性的脉状(网状)化合物主要是铁的碳氮化合物,研究表明,加强对高速钢软氮化工艺中碳渗剂及渗碳过程的控制,是控制其软氮化脆性的重要因素。     

新型合金工具钢软氮化渗层组织结构的研究

采用光学显微镜及X射线衍射仪分析了一种新型合金工具钢软氮化渗层的组织形貌和相结构,并与传统的高速钢进行比较。结果表明,该钢经过560℃×3h软氮化后渗层显微组织是由γ′和合金氮化物及碳化物组成的扩散层,未见连续的ε相形成。与传统高速钢比较,在相同工艺条件下渗速较快,渗层较深,脉状氮化物级别较低,渗层具有良好的综合性能。     

摩托车轴承保持架表面处理后组织与性能

针对摩托车曲轴轴承保持架采用软氮化工艺进行表面处理后的氮化层组织结构、渗层厚度、渗层硬度、耐磨性、抗拉强度、抗氧化性能等进行全面、系统分析。     

真空软氮化提高模具寿命的研究

本文探讨了真空软氮化工艺参数对渗层特性的影响,并与气体软氮化、真空氮化进行了比较。通过离子探针、扫描电镜、波谱仪、声发射等对渗层C·N含量及分布、相结构、应力状态、抗咬合、脆性等进行测试。表明真空软氮化新工艺、具有渗速快、脆性小、变形小、节能、耐磨性和抗咬合性能好等特点。该工艺用于标准件十字槽冲头和六方下冲,寿命均达到30多万件,提高寿命10多倍,技术经济效益极为显著。     

稀土离子氮碳共渗的研究

本文通过试验所取得的数据，对纯氨离子氮化、离子软氮化和稀土离子软氮化三种工艺进行了醒目的对比，稀土元素显著提高离子氮化渗速，对渗氮层具有明显的强韧化作用。对稀土作用机理提出自已的见解。     

深层气体软氮化工艺试验

<正> 一、前言钢在临界温度(ACl)以下,即在Fe-N共析温度530～570℃对钢件进行C-N共渗,以渗氮为主,渗碳为次的化学热处理方法。软氮化渗层并不软,硬度HV550～1100,因渗层韧性好,习惯上称为软氮化。软氮化与纯氮化比,前者因活性[C]原子起催渗作用,渗入速度高几倍,化合物渗层脆性小、韧性好,虽硬度稍低于纯氮化,但不受钢材限制,不须专门渗氮钢。与渗碳比,因温度低,时间短,变形小且有较好耐磨性、耐蚀性、抗粘结、抗咬合和抗疲劳等特性,填补了渗氮与渗碳之间的空白。软氮化在模具、工具和机械行业中得到广泛应用,     

深层气体软氮化工艺试验

一、前言钢在临界温度(AC1)以下, 即在Fe-N共析温度530～570℃对钢件进行C—N共渗,以渗氮为主,渗碳为次的化学热处理方法。软氮化渗层并不软,硬度H V550～1100,因渗层韧性好,习惯上称为软氮化。软氮化与纯氮化比,前者因活性[C]原子起     

175型柴油机球铁曲轴的气体氮碳共渗

本文介绍了175型柴油机球铁曲轴气体氮碳共渗(气体软氮化)工艺试验的情况及对共渗工艺参数、渗层组织、性能和变形等有关问题的探讨。     

通氨滴醇加催渗气体软氮化在压铸模上的应用

以液氨、乙醇为原料,氯化铵、海绵钛作催渗剂的催渗气体软氮化,是继我厂使用电解气相软氮化加蒸汽复合处理工艺于3Cr2W8V钢制压铸模多年基础上的一项节能新工艺。恢工艺具有上马快、工艺方法简便、渗速快、渗层质量好、适用性广的特点。近一年半来处理了近80副新模具,工艺质量稳定,效益显著。     

氮碳共渗工艺过程中化合物层的形成过程

在RJJ-105井式气体渗氮炉中,对45钢试块进行氮碳共渗,渗剂为氨气和甲醇。结合软氮化的工作原理,通过控制氨气供量、甲醇滴入量和氮碳共渗时间等主要工艺参数,使试块获得不同厚度的表层化合物层,即白亮层。结果表明,在570℃下,当氮势达到一定量以后,随着氮碳共渗时间的延长,白亮层增厚,表层显微硬度增加,但氮碳共渗时间超过4h以上时,随着时间的延长,白亮层厚度无明显变化,但是表面出现明显的疏松,表层显微硬度下降。     

结构钢氮碳共渗后韧性下降的原因分析

探讨了结构钢经氮碳共渗处理后其冲击韧性值下降的原因。通过金相分析、扫描电子显微镜对渗层的观察及对一些工艺参数的分析，得出其主要原因是共渗过程中由于氢渗入基体，同时在晶界形成Fe-N化合物，结果导致结构钢变脆。采用去氢退火方法可除去大部分氢，同时会使Fe-N化合物穿晶析出，降低了Fe-N化合物在晶界附近偏聚程度，减少了沿晶脆断倾向，显著提高结构钢经N-C共渗后的冲击韧性值。     

An investigation on the erosion resistance of rare earths nitrocarburized 40 Cr steel

The effect of rare earths (RE) on erosion resistance of nitrocarburized 40 Cr steel is investigated. Results indicate that a significant improvement occurs in erosion resistance of nitrocarburized 40 Cr steel by introducing RE in nitrocarburizing processes comparing conventional nitrocarburizing processes. Measurement of mechanical properties exhibits that both hardness and toughness of nitrocarburized 40 Cr steel increase in the case using RE nitrocarburizing processes comparing the conventional. Metallurgical microscopy reveals that there is an improvement in the nitrocarburizing layer microstructure attributed to an introduction of RE in nitrocarburizing, which results in an improvement in erosion resistance and mechanical properties. Surface morphology observation of tested samples reveals that predominantly furrow-like peeling from plastic deformation are observed in RE nitrocarburizied 40 Cr steel, while the furrow-like peeling with initial cross crack and large grinding peelings takes place in conventionally nitrocarburized samples.     

W18Cr4V钢钛催渗盐浴氮碳共渗工艺研究

试验研究了钛催渗对W18Cr4V钢盐浴氮碳共渗的影响,分别就盐浴处理温度和时间等工艺参数对试样表面性能影响进行了研究。试验结果表明,钛催渗剂的多少对提高共渗层表面硬度具有显著作用,钛催渗可显著缩短盐浴处理时间,有效提高渗层厚度和硬度,能得到质量良好的渗层。     

低温钛催渗对Cr12钢盐浴氮碳共渗的影响

试验研究了钛催渗对Cr12钢低温盐浴氮碳共渗的影响。结果表明：钛催渗具有明显的催渗效果,可使氮、碳原子的渗入速度显著加快,提高渗层厚度和渗层硬度,同时钛催渗盐浴氮碳共渗工艺简单方便,共渗温度低,共渗时间短,具有明显的节能特点。     

固体(粉末和膏剂)氮碳共渗试验研究

氮碳共渗一般都用液体和气体法,然而通常不被采用的固体法也有其独特的优点.后者不需要专用加热设备,可以在普通箱式炉中进行,而且操作简单,所以非常适用于单件或小批量生产.本文对固体(包括膏剂)氮碳共渗的渗剂成分和操作工艺进行了试验研究,取得了良好结果.     

Investigation of fatigue properties of shot peened and plasma nitrocarburized P/M FC0205 steel

One of the widely used powder metal materials in automotive industry, which is copper steel FC 0205 (Fe + 2% Cu + 0.5% C), was used in this study. The pressed samples has been prepared at the compression pressure of 680 MPa and sintered in conventional furnace at 1120°C for 30 minutes. The samples with 7 Mg/m³ densities were used as fatigue and shot peening processes. Shot peening were applied with 20A and 32A and the others were not peened. Plasma nitrocarburizing process was performed at 555°C for 2 hours under 600–900 Pa pressure. Fatigue tests were conducted at room temperature on a rotating bending type fatigue test device. It was determined that shot peening should be used where increased fatigue strength is needed, and plasma nitrocarburizing should be preferred where surface hardness is required, and plasma nitrocarburizing after shot peening process is much more useful.     

轴承保持架低压脉冲真空氮碳共渗工艺

分析轴承保持架低压脉冲真空氮碳共渗工艺原理,对影响保持架表面白亮层深度和表面硬度的脉冲工艺参数:脉冲幅度、保压时间及总脉冲时间进行了正交试验。应用正交试验极差分析法分析了脉冲工艺参数与白亮层深度和表面硬度的影响趋势,最终确定出给定试验条件下的最佳脉冲工艺参数。     

Scuffing resistance of salt bath nitrocarburized medium carbon steel

The usefulness of the ferritic nitrocarburizing treatment for improving the tribological properties of ferrous components is well established. However, the thin compound layer of beneficial epsilon carbonitride that develops at the surface lacks the ability to bear high Hertzian stresses. Nitrocarburizing in the austenite phase field of the Fe---N---C system overcomes this disadvantage since the formation of a hard zone of martensite-bainite below the compound layer provides the back-up to withstand point loads. Results of the Falex scuffing test indicate that the failure load increases on account of the thicker compound layer at the surface. The results indicate further that the frictional heat generated during the test coupled with working by the jaws convert the retained austenite present in the sub-compound layer to harder microconstituents. The study suggests that the austenitic treatment could be useful for applications involving simultaneous heat and work such as hot working dies.