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。     

低温盐浴钛催渗氮碳共渗研究

阐述了钛催渗低温盐浴氮碳共渗机理,重点研究了钛催渗对几种不同材料钢氮碳共渗的影响。研究结果表明;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,提高渗层深度和渗层硬度。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。     

模具钢表面盐浴渗钛层的制备及性能研究

采用盐浴法在Cr12Mo V冷作模具钢表面进行渗钛处理,研究了不同温度和时间对渗层厚度的影响。通过金相显微镜、扫描电镜、X射线衍射仪、显微硬度测试仪和旋转摩擦试验仪分析了渗层的显微形貌、相结构、表断面硬度和耐磨性能。结果表明:通过配方优选,在适宜的渗入温度(1000℃)和时间(6h)下,可在模具钢表面形成致密、厚度约13μm的渗钛层,相组成主要为Ti C,渗层具有较高的表面硬度(约2789HV0.3)。室温干摩擦试验表明,与基体相比,相渗层试样的磨损量降低约17倍,平均摩擦系数为0.4054,仅为基体的70.6%,说明模具钢盐浴渗钛处理后具有较佳的耐磨减摩性能。     

稀土元素对45钢固体渗硼催渗作用的研究

通过在自制渗硼剂中加入不同比例的稀土成分,进行对比试验,研究了稀土元素对45钢固体渗硼的催渗作用及其对其渗层的显微硬度的影响。研究表明．在渗剂中加入适量的稀土元素,对渗硼有一定的催渗作用,使渗硼层的显微硬度得到明显提高,但渗层的峰尖深度随稀土加入量的增加变化不明显。     

硬质合金稀土固体渗硼工艺研究

硬质合金具有较好的强度和韧性,在工业领域中应用广泛。通过固体渗硼工艺在硬质合金表面形成一层硬化层,能提高其硬度和耐磨性。对YG类硬质合金进行了稀土固体渗硼试验,采用XRD和金相显微镜观察渗硼层物相和厚度,研究了硬质合金Co含量、渗硼温度、渗硼时间和渗剂配方对渗硼层厚度的影响。结果表明,各种工艺参数均对渗硼层厚度有不同程度的影响,稀土元素具有催渗作用。     

V_2O_5对H13钢在盐浴硫氮碳共渗中的影响

研究了在加入 V2 O5后的低温无毒硫氮碳共渗对 H1 3钢的影响。结果表明 ,这种处理能有效地催渗并且减缓由表至里的硬度梯度 ,V2 O5可提高 H1 3钢共渗层的耐磨性、硬度及表面与其基体结合强度 ,能取得较好的经济效益     

40Cr气体多元共渗后耐磨性研究

为了提高上述零件的耐磨性,延长使用寿命,对40Cr钢进行气体多元共渗处理。对渗层的相结构与形貌进行X射线衍射和扫描电镜分析,表明材料表面形成了由ε相组成的白亮层和由氮化物组成的扩散层,氮化物和渗层中存在的硬度很高的碳化物提高了材料的表面硬度。对气体多元共渗后的40Cr进行摩擦磨损试验,表明处理后40Cr的表面摩擦因数较处理前显著减小,其耐磨性得到较大提高,并随温度提高而更加显著。     

V2O5对H13钢在盐浴硫氮碳共渗中的影响

研究了在加入V2O5后的低温无毒硫氮碳共渗对H13钢的影响。结果表明，这种处理能有效地催渗并且减缓由表至里的磁度梯度，V2O5可提高H13钢共渗层的耐磨性、硬度及表面与其基体结合强度，能取得较好的经济效益。     

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。     

温度和时间对真空铬钒共渗销轴渗层的影响

链条作为链传动系统中非常重要的组成部分,在工作时销轴和套筒会发生滑动摩擦从而产生磨损,达一定程度就会导致链条伸长失效.针对失效形式,将销轴表面进行铬钒共渗处理,提高其表面硬度,进而提高销轴的耐磨性,并通过试验研究不同温度以及时间对渗层的影响,提高渗层的质量,从而大大提高链条的耐磨性能.     

金刚石表面镀覆金属的性能研究

对人造金刚石表面进行盐浴镀Ti和化学镀Ni、Cu处理后 ,用SEM观测镀后金刚石的表面形貌及镀层界面 ,并测试分析了镀后金刚石的抗压强度和抗热蚀能力。结果表明 ,盐浴镀Ti的镀层与金刚石的结合界面比化学镀层更为致密 ;经化学镀后的金刚石抗压强度明显提高 ,镀Ti和镀Ni的金刚石抗热蚀能力较好。     

Several plasma diffusion processes for improving wear properties of Ti6Al4V alloy

Different kinds of diffusion processes, plasma nitriding, oxidizing and oxynitriding as of a combination of other two, have been applied to Ti6Al4V alloy to evaluate the effect of treatment times (1 and 4 h) and temperatures (650 and 750 °C) on wear properties of the alloy. It was observed that a hard modified layer was produced on the surface of the alloy after each diffusion process. While TiN and Ti₂N phases form in the modified layer with plasma nitriding, mainly TiO₂ phase forms after plasma oxidizing treatment. The wear tests performed at different normal loads showed that all treated samples, except for nitrided and oxidized at 650 °C for 1 h, exhibited higher wear resistance than untreated Ti6Al4V alloy. The plasma nitrided samples showed adhesive wear. On the other hand, while the plasma oxidizing samples displayed adhesive wear at lower loads, wear mechanism changed to abrasive wear as the load increased because the oxide film which covers the surface was broken during the sliding at higher loads.     

TEM studies of the nitrided Ni-Ti surface layer

The structure of surface layer, obtained on the nearly equiatomic Ni‐Ti alloy after nitriding under glow discharge conditions at temperatures 700 or 800 °C, was investigated. The structural characterization of the intruded layer was performed on cross‐sectional thin foils by the use of the transmission and scanning electron microscopes. The obtained results show that the nitrided layers consist mainly of the nanocrystalline TiN phase and small amount of Ti₂N. Between the nitrided layers and β‐NiTi matrix an intermediate Ti₂Ni phase layer was observed.     

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.     

Multi-pass scratch test behavior of modified layer formed during plasma nitriding

316L stainless steel and Ti6Al4V alloy were plasma nitrided at different treatment parameters, and the wear behaviors of the modified layers formed on the surface during nitriding were investigated by multi-pass scratch test. Phase structure and cross-sections of modified layers were also examined with XRD and SEM. While a single modified layer formed on surface of the 316L stainless steel, both modified and diffusion layers were observed on the surface of the Ti6Al4V alloy after nitriding. As a result, it was observed that phase structure and thickness for modified layers of 316L stainless steel and Ti6Al4V alloy, respectively, were the significant parameters for friction coefficient and wear rate. In addition, diffusion layer formed during the nitriding process caused on increase of wear resistance of Ti6Al4V alloy by supporting the modified layer on the surface.     

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。     

A comparative study on the tribological behaviors of nitrided and sulfur-nitrided 35CrMo steel lubricated in PAO base oil with MoDTC additive

A nitrided layer on 35CrMo steel was prepared by the ion nitriding process, and then a sulfur-nitrided layer was obtained by low temperature ion sulfuration. The results showed that both the nitrided and sulfur-nitrided surfaces improved the wear resistance efficiently under PAO lubrication, and exhibited the best wear resistance and friction-reducing property under PAO with 0.75% MoDTC lubrication. Compared with the plain and nitrided surfaces, the sulfur-nitrided surface exhibited the best synergistic effect with MoDTC displaying the lowest friction coefficient and wear volume. The mechanism of the best effect was due to MoS₂ and FeS formed on the sulfur-nitrided surface.     

A comparative study on the tribological behaviors of nitrided and sulfur-nitrided 35CrMo steel lubricated in PAO base oil with MoDTC additive

A nitrided layer on 35CrMo steel was prepared by the ion nitriding process, and then a sulfur-nitrided layer was obtained by low temperature ion sulfuration. The results showed that both the nitrided and sulfur-nitrided surfaces improved the wear resistance efficiently under PAO lubrication, and exhibited the best wear resistance and friction-reducing property under PAO with 0.75% MoDTC lubrication. Compared with the plain and nitrided surfaces, the sulfur-nitrided surface exhibited the best synergistic effect with MoDTC displaying the lowest friction coefficient and wear volume. The mechanism of the best effect was due to MoS₂ and FeS formed on the sulfur-nitrided surface.