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。     

锻造模具钢H13的热处理及氮碳共渗

研究了H13钢的热处理和氮碳共渗工艺,指出了H13钢适宜的热处理工艺为1030％淬火＋600％回火,然后再580％氮碳共渗4．5h。表面硬度可达900HV,渗氮层深0．2mm。采用H13钢的锻造模具在应用新工艺后,其寿命可提高1倍。     

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。     

钢的铬硼共渗工艺

本文对不同含碳量的钢:A3、45、T1O和Cr06钢进行了依次渗硼、渗铬和铬硼共渗的工艺试验研究;同时研究了合碳量、加热温度、保温时间对共渗层深度的影响。试验表明,可以获得显微硬度高达HV_(0.1)2875的硼铬共渗层,具有良好的耐磨性和耐蚀性。     

稀土对模具钢低温氮碳共渗层性能的影响

研究了3Cr2W8V钢经稀土不同浓度低温氮碳共渗处理后的耐磨性、耐蚀性、抗氧化性和热疲劳性能。结果表明,稀土不仅具有明显的催渗作用,而且明显改善渗层的上述性能;稀土的催渗和改性存在一个最佳浓度,对3Cr2W8V钢为3%～5%。     

高浓度碳氮共渗在高速钢冷挤压模上的应用

本文主要对W18Cr4V 钢高浓度碳氮共渗后的渗层成份、显微组织、硬度分布,共渗时间对渗层深度的影响以及实际使用效果等进行了研究分析;并对高浓度渗碳的机理等问题进行了探讨。研究结果表明,W18Cr4V 钢制黑色金属冷挤压模经高浓度碳氮共渗——直接淬火——低温回火后,可显著提高其表面硬度、耐磨性和抗咬合性能,使用寿命较常规热处理可提高4～5倍。     

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     

W4Mo3Cr4V高速钢稀土多元共渗层的性能

利用稀土多元共渗工艺将碳、氮、氧、硫、硼、稀土元素同时渗入W4Mo3Cr4V高速钢表面,研究了多元共渗层的硬度、耐磨性能及表面残余应力等。结果表明:多元共渗层由化合物层(主要为氧化物、硫化物和碳化物)和扩散层组成;共渗层显微硬度最高达1 150 HV左右;多元共渗层较钢表面的摩擦因数大幅降低,耐磨性能提高,其表面产生了较高的残余压应力,有利于提高材料的疲劳性能。     

高速钢刀具的C,N,O,B共渗处理

哈尔滨量具刃具厂传统的高速钢刀具处理工艺为氧氮化。近几年,为进一步提高刀具的耐用度,我们试验进行了C、N、O、B共渗处理,并添加稀土以催渗,取得了较好的结果,部分刀具已投入小批量生产。 一、共渗材料及方法 共渗用材料为W6Mo5Cr4V2高速钢,经1220～1240℃分级淬火和三次540～569℃×1h回火,硬度     

稀土对钢渗硼动力学影响的研究

对45钢、5CrMnMo钢、3Cr2W8V钢进行固体渗硼的试验研究表明,稀土元素对钢的渗层生长有促进作用,但稀土添加量有一个最佳值,其催渗效果同钢的成分、渗硼工艺有关。建立的渗层生长动力学数学模型可为确定渗硼工艺参数提供依据,从而为渗硼(硼稀土共渗)的应用开拓了新途径。     

提高齿形链耐磨性能的措施和试验研究

提出了提高齿形链耐磨性能的改善措施,阐述了齿形链链板冲孔光亮带、销轴热处理表面硬度以及销轴表面粗糙度与齿形链耐磨性能的关系.试验结果表明,提高链板冲孔光亮带、销轴热处理表面硬度以及销轴表面粗糙度可以显著提升了齿形链的耐磨性能,与改善之前对比,耐磨性能提高了50％.实践表明,该措施对于齿形链耐磨性能的提高是十分有效的.     

Modelling of back tempering in laser hardening

Back tempering is one of the most critical problems in laser hardening of extended surfaces. In this type of treatment, several laser tracks are slightly overlapped to obtain a uniform hardened surface. Due to the overlapping, tempered zones are generated on the treated surface with the consequent lack of uniformity in the surface hardness. In this work, a regression model was developed to estimate the loss of hardness due to the tempering effect as a function of the thermal cycle. A specific test, named laser surface treatment test, was designed and executed to reproduce the hardness reduction due to the tempering effect. An analytical thermal model was developed to evaluate the thermal cycle undergone by the material during this test. By the results of the laser surface treatment test combined with the analytical model, a prediction model was estimated. Good agreement was found between predicted and measured hardness decrease, and the identified model could be integrated in a numerical code to evaluate the optimal process parameters.     

TC4固态渗碳化硼的试验研究

为改善钛及钛合金的表面性能,对TC4在不同温度条件下固态渗碳化硼后的渗层显微组织及硬度等情况进行了试验研究。结果表明,渗层表面为致密分布的化合物层,而在基体内部则形成沿晶界分布的板条状或等轴状的颗粒扩散层;表面渗碳化硼处理可以显著提高TC4的表面硬度,而且由表及里具有良好的硬度梯度;断口形貌分析发现材料由韧性断裂转变成脆性断裂。该工艺设备简单、操作方便、效率高、成本低。     

The effect of surface hardness on friction

The influence of bulk hardness, surface hardness and strain-hardening rate on the frictional behavior of Cu-Sn and Cu-Al alloys was investigated. Unlubricated specimens were subjected to severe relative sliding against tool steel (D2) and aluminum bronze (Ampco 25) anvils under constant interference conditions. A microindentation hardness survey, from the surface into the bulk, was carried out on sections of the specimens both before and after testing.The highest hardness was measured immediately below the wear surface; this hardness value was found to increase linearly with an increasing instantaneous strain-hardening rate. However, no correlation could be detected between the coefficient of friction and the bulk hardness, the strain-hardening rate or the surface hardness. There was a general trend for the coefficient of friction to increase with the greater increase in hardness produced during sliding against Ampco 25. Drawing on observations of metal transfer and surface damage made earlier, this increase could be attributed to the formation of junctions that were stronger than the parent material. There was no correlation with hardness increase when sliding against D2 and the coefficient of friction was often, but not always, lower. Thus a hardness increase during sliding led to increasing friction only with the metallurgically highly compatible pairs while differences in compatibility rather than hardness increase governed the magnitude of friction with less compatible pairs.     

Scuffing Behavior of Al-Si Alloy Modified by Fine Particle Bombarding and Powder Impact Plating Hybrid Surface Treatment

The occurrence of scuffing is widely observed on tribological components made of Al-Si alloys. The object of this study is to investigate the scuffing behavior of Al-Si alloy modified by fine particle bombarding (FPB) and powder impact plating (PIP) hybrid surface treatment. FPB treatment, PIP treatment, and hybrid treatment consisting of FPB and PIP were conducted on Al-Si alloy samples. The surface morphology, microstructure, and hardness of the samples were examined. Block-on-ring tests were performed to investigate the scuffing resistance of the samples. The test results show that the scuffing resistance of Al-Si alloy depends on the surface hardness and friction coefficient. Scuffing resistance is improved by FPB treatment, which increases the surface hardness by nanocrystallization and reduces the friction coefficient by decreasing the surface roughness and producing a microdimpled surface. PIP treatment reduces the friction coefficient by generating an Sn coating on the surface of the sample, thereby improving the scuffing resistance. After FPB and PIP hybrid surface treatment, the surface hardness is increased and the friction coefficient is further reduced. Therefore, the sample modified by hybrid surface treatment exhibits the highest scuffing resistance.     

挤压轮表面PCVD法制备T(iCN)涂层组织与性能

通过挤压轮的失效形式分析,表面裂纹是引起其失效的主要原因。应用PCVD法对挤压轮(H13)进行表面改性处理,在其表面备制了一层T(iCN)涂层。通过扫描电镜观察T(iCN)涂层表面的形貌以及断口组织形貌,用EDS对其化学元素进行能谱分析,测试了T(iCN)涂层表面显微硬度和粗糙度。结果表明T(iCN)涂层中所含Ti元素的质量和原子百分比为最多,涂层界面结合良好,其表面硬度为1004HV,粗糙度为1.23μm,有利于改善其疲劳性能和延长使用寿命。     

Effects of Nd:YAG Laser Surface Treatment on Tribological Properties of Cold-Sprayed Ti-6Al-4V Coatings Tested against 100Cr6 Steel under Dry Condition

The surfaces of cold-sprayed Ti-6Al-4V (Ti64) coatings were laser irradiated with different laser powers of 50–200 W to study the effects of Nd:YAG laser surface treatment on their tribological properties. The hardness of the laser-treated Ti64 coatings became higher with higher laser power due to the more rapid cooling caused by a larger temperature difference between the coating temperature and room temperature. The wear of the laser-treated Ti64 coatings tested against 6-mm 100Cr6 steel balls under dry condition at room temperature decreased with increased laser power as a result of their increased surface wear resistance associated with their increased surface hardness. It could be concluded that the laser surface treatment of the cold-sprayed Ti64 coatings improved their surface wear resistance compared to that of the untreated Ti64 coatings.     

时效工艺对新型铸造铝铜合金微观组织和性能的影响

对不同时效工艺条件下新型铸造铝铜合金的力学性能、微观组织结构进行了分析,结果表明:新型铸造铝铜合金有很好的时效硬化特性,当保温时间为4 h时,硬度可达到较高值;经时效处理后试样的晶粒尺寸明显减小,晶界和晶粒内部均有大量析出相析出且分布均匀。     

Relation between scuffing resistance and the increase in surface hardness during tests under conditions of rolling/sliding

The effect on scuffing resistance of a change in the condition of the rubbing surfaces, especially surface hardness, was investigated using a two-disc machine. Scuffing resistance increased with increasing surface hardness during testing. The increase of surface hardness by work hardening is more beneficial in preventing scuffing than is a change in carbon content or heat treatment. Work-hardened disc surfaces allow surface film formation as a result of plastic deformation. Materials with large Meyer indices and high surface hardness are less prone to scuffing.