瓦楞辊的表面强化工艺

研究了经渗氮、碳氮共渗后高频淬火处理后42CrMo及45钢瓦楞辊试样的表面组织和力学性能。结果表明,两种试样经渗氮加高频淬火处理后表层主要为氮化物和回火马氏体组织;碳氮共渗加高频淬火处理后试样表层组织主要为回火马氏体和有少量氮化物。45钢和42CrMo钢试样经过处理表面硬度分别达到740和800 HV0.1,经高频淬火处理后,试样表面硬化层有较好的硬度梯度。     

曲轴的表面化学热处理强化

本文系统介绍了国内外发动机曲轴的表面化学热处理强化，包括渗碳淬火、渗氮、盐浴氮碳共渗、气体氮碳共渗、离子软氮化和表面化学复合热处理强化等方法。文中总结了这些化学热处理强化方法的工艺、设备及特点等，供发动机制造厂家或专业曲轴制造厂家参考。     

6105型柴油机曲轴的变形控制及离子氮碳共渗工艺

本文详细介绍了锻钢曲轴氮碳共渗弯曲变形的控制方法以及采用大功率脉冲电源对曲轴进行离子氮碳共渗处理工艺 ,氮碳共渗后曲轴的疲劳强度、耐磨性、可靠性等比轴颈淬火加圆角喷丸处理曲轴的性能有大幅提高     

8620H钢拨叉的热处理

8620H钢拨叉单件质量1.05kg,需进行碳氮共渗和淬火、回火处理,达到表面硬度680~800HV0.3、心部硬度30~45HRC和至550HV0.3的有效硬化层深度0.1~0.3mm。采用UBG渗碳炉对拨叉进行了3次碳氮共渗及淬火和低温回火工艺试验,通过适当缩短碳氮共渗时间、降低淬火温度、调整淬火油温及其搅拌烈度,最终达到了拨叉的质量要求要求。     

6105型柴油机曲轴的变形控制及离子氮碳共渗工艺

本文详细介绍了锻钢曲轴氮碳共渗弯曲变形的控制方法以及采用大功率脉冲电源对曲轴进行离子氮碳共渗处理工艺，氮碳共渗后曲轴的疲劳强度、耐磨性、可靠性等比轴颈淬火加圆角喷丸处理曲轴的性能有大幅提高。     

非调质钢表面硬化处理工艺

试验用非调质钢为F35MnV、F38MnVS、F40MnVS、F45MnVS及F49MnVS铁素体-珠光体钢和F12Mn2VBS贝氏体钢。对这些钢进行了表面硬化处理试验。结果表明,铁素体-珠光体型非调质钢可采用气体渗氮、离子渗氮和气体氮碳共渗以提高其表面硬度和耐磨性,但贝氏体非调质钢氮碳共渗处理后,其冲击韧度从46.7 J降低到了35.0 J,故不宜采用该工艺进行表面硬化。此外,F40MnVS钢的高频感应淬硬层表面硬度和硬化层深度与45钢的基本相同,经渗氮处理的F35MnV和F40MnVS钢渗层的化合物层比40Cr、45和38CrMoAlA钢的薄,而扩散层较厚者厚,表面硬度比40Cr、45钢高,比38CrMoAlA钢低。经气体氮碳共渗的非调质钢具有良好的综合力学性能。     

稀土氮碳硼共渗对45钢疲劳性能的影响

研究了稀土氮碳硼共渗对45钢疲劳性能的影响。结果表明，稀土氮碳硼共渗处理后，45钢疲劳寿命显著提高，裂纹形成延迟，裂纹扩展速度降低。表面出现残余压应力和表面硬度提高是稀土氮碳硼共渗处理改善45钢疲劳性能的主要原因。     

气体氮碳共渗及盐浴硫氮碳共渗球铁曲轴性能对比

对比了球墨铸铁曲轴经正火加气体氮碳共渗及正火后盐浴硫氮碳共渗的抗疲劳性及耐磨性。曲轴的平面弯曲疲劳及台架耐久试验表明:两种低温化学热处理工艺处理后的曲轴比正火加中频淬火曲轴耐磨性及耐疲劳性均有明显的提高,但气体氮碳共渗曲轴略优于盐浴硫氮碳共渗曲轴。     

激光淬火预处理对40Cr钢离子碳氮氧硫共渗层组织与性能的影响

通过观察金相组织、测量表面硬度和渗层深度、检测耐蚀性等方法,研究了激光淬火预处理对40Cr钢离子碳氮氧硫共渗层组织和性能的影响。结果表明,激光淬火预处理缩短了离子碳氮氧硫共渗的时间,降低了共渗的温度。激光淬火预处理可提高共渗工件表面硬度及渗层深度,经激光淬火/离子多元共渗处理后,40Cr钢表面的ε-Fe2-3N相和FeS含量增多,Fe3C含量减少,可明显地改善其耐蚀性。     

45钢淬火与氮碳共渗复合处理工艺

对45铜进行了淬火与氯碳共渗复合处理工艺试验和传统的氮碳共渗处理,分析了经两种工艺处理后45铜的显微组织及显微硬度。结果表明,45铜经淬火与氮碳共渗复合处理可获得更深的渗层及更好的渗层硬度分布,从而进一步提高了零件的耐磨、耐蚀性及疲劳强度、     

The microstructure and properties of 17-4PH martensitic precipitation hardening stainless steel modified by plasma nitrocarburizing

17-4PH martensitic precipitation hardening stainless steel was plasma nitrocarburized at 430 °C and 460 °C for 8 h. The nitrocarburized layers were characterized by optical microscope, scanning electron microscope, X-ray diffractometer, microhardness tests, pin-on-disc tribometer and the anodic polarization method in a 3.5% NaCl solution. The results show that the microstructure of plasma nitrocarburized layer is characterized by a compound layer with no evident diffusion zone. The phases in the 430 °C treated layer are mainly of γ′-Fe₄N, nitrogen and carbon expanded martensite (α′_N), and some incipient CrN phases. When the temperature increases up to 460 °C, there is no evidence of α′_N phase. The processes of bulk precipitation hardening and surface treatment by plasma nitrocarburizing can be successfully combined in a single-step process on this steel. The hardness of modified layer can reach up to 1186HV, which is 3 times higher than that of untreated steel. The wear and corrosion resistance of the specimens can be apparently improved by plasma nitrocarburizing. The 460 °C/8 h treated specimen has the best wear and corrosion resistance in the present test conditions.     

气缸套的高频感应加热淬火畸变

气缸套材料为合金铸铁,其内表面要求淬硬以提高耐磨性。采用高频感应淬火可使气缸套获得必要的表面硬度、淬硬层深度和显微组织,但畸变量较大。试验表明,对气缸套进行去应力退火,合理设计感应器,优化感应淬火的各项工艺参数,可使气缸套的淬火畸变量控制在要求范围内。     

Layer growth kinetics and wear resistance of martensitic precipitation hardening stainless steel plasma nitrocarburized at 460°C with rare earth addition

To study the effect of rare earth (RE) addition on low temperature plasma nitrocarburizing of martensitic precipitation hardening stainless steel, 17-4PH stainless steel was plasma nitrocarburized at 460 °C for different times with RE addition. The modified layers were tested by optical microscope, scanning electron microscope, X-ray diffraction, microhardness tester and pin-on-disc tribometer. The experimental results show that the layer depth of plasma RE nitrocarburized layer can be increased up to 56% compared with plasma nitrocarburizing without RE addition. Incorporation of RE element is beneficial to the formation of nitrogen and carbon expanded martensite (α′_N). The surface microhardness of plasma RE nitrocarburized layer can be increased to 1286 HV and higher up to 80 HV than that obtained from the conventional treated one. The friction coefficient of martensitic stainless steel can be dramatically decreased by low temperature plasma nitrocarburizing with RE addition, and the friction coefficient of the modified specimens decrease gradually with increasing process time in the present test condition.     

重型汽车内齿圈气体氮碳共渗质量分析

利用宏观分析、显微检验、硬度测试和装车试验等手段，对引进奥地利重型汽车内齿圈按照新的气体氮碳共渗工艺处理后的质量进行了研究。结果表明，新工艺不仅能达到国外设计指标，还比Tenifer工艺具有更高的抗磨损能力与更低的成本。     

9CrWMn钢复合TD盐浴渗铬的研究

对9CrWMn钢进行复合TD盐浴渗铬处理,即先固体氮碳共渗预处理,再盐浴渗铬.对比了复合渗和单一盐浴渗铬的渗层微观形貌,分析了渗层的相结构、显微硬度和耐磨性.研究表明,氮碳共渗顸处理对TD盐浴渗铬的催渗效果明显,复合渗的渗层在厚度、截面硬度分布及耐磨性等方面均优于单一盐浴渗铬的渗层.该复合TD盐浴渗铬工艺可降低TD渗铬...     

表面感应淬火对45钢滚动磨损特性的影响

针对传统热处理后45钢耐磨性较低的缺点,研究了正火 表面感应淬火热处理后45钢相对ZG31Mn2Si摩擦副的滚动磨损特性和磨损机理.测试了试验载荷、材料硬度与磨损失重的关系,采用扫描电镜分析了感应淬火热处理后不同硬度45钢的磨损形貌及变化规律.结果表明:当载荷恒定,磨料硬度Ha大于被磨材料45钢硬度Hm时,45钢随着感应淬火后自身硬度的提高,耐磨性明显提高,为硬磨料磨损;Ha＜Hm时,随着材料硬度的提高,磨损量变化很小,为软磨料磨损;其滚动磨损机理随着表面感应淬火后硬度的升高由塑变磨损转变为犁沟磨损.     

台阶轴连续感应淬火组织硬度分布预测及其工艺优化

建立了S45C钢台阶轴连续感应淬火过程的分区模拟模型,加载相应的物性和工艺参数,采用感应加热结束时刻轴径向温度分布、Maynier模型、Carsi修正模型和钢CCT曲线拟合预测其淬硬层深度分布,通过联动分析各方法的模拟结果优化了连续感应淬火工艺参数。结果表明,感应淬硬层中关键点b的100%、50%和0%马氏体的模拟深度分别为1.31、1.49和2.97 mm,误差分别为-12.67%、-13.87%和-1.00%,关键点e分别为1.44、2.02、2.54 mm,误差分别为-4.00%、-3.38%和-18.06%,与试验结果较吻合。通过感应淬火工艺参数改变和物理模型调整等探讨了零件各点处的轴径淬硬层变化,给出拟优化的感应淬火工艺参数。初步探讨了换热系数h变化对感应淬硬层的影响。     

不锈钢盐浴氮碳共渗后的组织和耐蚀性

探讨了几种奥氏体钢、马氏体不锈钢经盐浴氮碳共渗处理后共渗层特点,并对进行了测炒锈钢零件选和氮碳共渗工艺提高耐磨性提供了有效的参考。     

低温离子氮碳共渗温度对AerMet100钢摩擦学性能的影响

研究了不同温度对AerMet100钢渗氮层和氮碳共渗层的显微组织、表面硬度、渗层截面硬度梯度以及耐磨性的影响,并考察了渗层的磨损机理。结果表明,氮碳共渗层相较于渗氮层表面生成的化合物更加细小,表面更加平整光滑;离子渗氮、离子氮碳共渗处理都可显著提高AerMet100钢的表面硬度;随着温度的增加,共渗层厚度也明显增加;氮碳共渗层比渗氮层具有更低的摩擦因数,在共渗温度为480 ℃时氮碳共渗试样具有最低摩擦因数和磨损率,表现出最佳的耐磨性。渗氮层的磨损机理为氧化磨损和表面疲劳磨损,氮碳共渗层的磨损机理为氧化磨损、磨粒磨损以及表面疲劳磨损。     

Korrosionsverhalten nitrocarburierter Stähle

Corrosion behaviour of nitrocarburized steels Diffusion coatings have been used increasingly to modify surface properties of various machine components for several applications. In general, these coatings are used to improve the wear behaviour. Frequently, it is desirable that the corrosion behaviour will be improved at the same time. In this investigation, the corrosion behaviour of various diffusion coating-substrate-combinations has been studied. The coatings developed by three different nitrocarburizing processes, namely saltbath, gas and plasma nitrocarburizing, were conducted on five various steel substrates. These substrates were St 52-3, Ck 45, 42 CrMo 4, 30 CrNiMo 8 and × 20 Cr 13. The thickness of the compound layers and their porosity were measured using optical microscopy. The structure of the compound layers was characterized using an X-ray diffractometer and their surface roughness by a stylus profilometer. The corrosion test was carried out using a salt-water spray test. The predominant corrosion mechanisms have been evaluated using scanning electron microscopy. It was found that the employed nitrocarburizing processes have improved the corrosion resistance of all tested coating-substrate-combinations comparing with that of the base materials. In general, the corrosion resistance increases with an increase of the compound layer's thickness and after an oxidation process. The best coating-substrate-combinations to improve the corrosion behaviour were salt-bath nitrocarburized tempering steels, whereas the thin layers of the plasma nitrocarburized specimens were the worst.