P-C法涂覆中碳结构钢的表面耐蚀性

应用Ｐ－Ｃ法对中碳结构钢进行Ｃｒ－Ｓｉ－Ａｌ复合涂覆,用电子探针及扫描电镜测定了涂层的表面成分及Ｃｒ,Ｓｉ,Ａｌ在涂层中的分布,用Ｘ射线衍测定了涂层中的相结构,将涂覆后的试样在酸、碱、盐溶液中进行腐蚀试验,结果表明,中碳结构钢经Ｐ－Ｃ法复合涂履后,表面优良的抗多种介质腐蚀的能力。     

P—C法涂覆提高结构钢耐蚀耐热性初探

应用Ｐ－Ｃ法对中，低碳钢进行了复合涂覆，用光学显微镜观察了涂层的形貌，初步探讨了中间金属和活化剂的配比，将涂覆后的试样进行盐水腐蚀和高温氧化试验，结果表明：普通碳素钢经Ｐ－Ｃ法涂覆后，具有优良的抗高温氧化和耐盐水侵蚀能力。     

P－C法涂覆提高结构钢耐蚀耐热性初探

应用Ｐ－Ｃ法（Ｐａｃｋｋ－Ｃｅｍｅｎｔａｔｉｏｎ）对中、低碳钢进行复合涂覆，用光学显微镜观察了涂层的形貌，初步探讨了中间金属和活化剂的配比。将涂覆后的试样进行盐水腐蚀和高温氧化试验，结果表明，普通碳素钢经Ｐ－Ｃ法涂覆后，具有优良的抗高温氧化和耐盐水侵蚀能力。     

表面变形对中碳合金结构钢疲劳强度的影响及强化机理

本文主要介绍中碳合金结构钢经整体塑性变形、热处理后再进行表面冷变形工艺是提高材料疲劳强度的有效途径。分析了强化规律与疲劳强度的关系,并探讨了疲劳裂纹扩展机制及表面冷变形强化微观机理。     

中碳高矾结构钢的研究

研究了中碳高钒结构钢正火后的组织和性能，结果表明，用中碳高钒结构钢代替调质钢具有良好的综合机械性能。     

P-C法涂覆中碳结构钢的表面耐蚀性

应用P C法 (Pack Cementation)对中碳结构钢进行Cr Si Al复合涂覆 ,用电子探针及扫描电镜测定了涂层的表面成分及Cr,Si,Al在涂层中的分布 .用X射线衍射测定了涂层中的相结构 .将涂覆后的试样在酸、碱、盐溶液中进行腐蚀试验 .结果表明 ,中碳结构钢经P C法复合涂覆后 ,表面具有优良的抗多种介质腐蚀的能力 .     

中碳高钒结构钢的研究

研究了中碳高钒结构钢正火后的组织和性能,结果表明：用中碳高钒结构钢代替调质钢具有良好的综合机械性能．     

中碳结构钢件的锻造成形与锻后调质一次完成的热加工新技术

本文是利用“形变诱发析出”原理通过控制热变形成形过程获得一种能在过冷分解时使碳化物呈颗粒状弥散析出的形变奥氏体状态,又通过控制冷却抑制先共析铁素体的析出,同时促进碳化物颗粒的析出,从而得到100％调质型组织,它达到了传统工艺的水平。     

表面纳米化中碳钢磨合磨损性能研究

为研究表面纳米化中碳钢在润滑条件下的磨合性能,用环-盘摩擦磨损试验机进行磨合磨损试验.分析在不同载荷下摩擦系数和摩擦振动信号多重分形谱参数的变化,通过磨损表面形貌探讨表面纳米化影响中碳钢磨损行为的原因.结果表明:在低、中负荷作用下,表面纳米化处理的中碳钢摩擦系数和振动信号多重分形谱参数较未处理的有所降低,其较高的表面活性可更好地吸附润滑油以形成油膜.因此,在低、中负荷条件下,表面纳米化可提高中碳钢磨合磨损性能.     

常用中碳钢氧化特性研究

钢铁材料的氧化烧损严重影响着材料的应用，一直是人们关注的对象．对45钢和40Cr两种中碳钢用不同温度加热，并测试其氧化失重率，得到两种钢在600℃～1100℃之间单位面积氧化失重曲线，同时得到在1100℃下的氧化皮生长动力学曲线．实验结果显示两种钢的氧化曲线变化规律相似，但并非呈现简单的指数关系，并且氧化失重率40Cr始终小于45钢，用XRD、SEM、EDS等方法对两种钢的氧化皮进行分析，得出40Cr钢氧化失重率相对减小的原因是因为Cr合金元素的烧结引起的相变所致．     

Tribological properties of dimpled surface alloying layer on carbon steel

The effect of surface structure and coating on tribological properties of 45^# carbon steel disc was analyzed. A Nd:YAG laser was used to generate microdimples on steel surfaces. Dimples with diameter of 150 m and depth of 50 m were distributed in an orbicular array on disc surface. Then the alloying element Mo was sputtered to 45^# carbon steel disc surface by means of double glow plasma technology. Diffusion Mo alloying layer with 30 min thickness and high hardness up to 0.025 was formed on the disc surface. Tribological experiments of three types samples (smooth, texturing and texturing+alloying) were conducted with a pin-on-disc tribometer. It is found that the dimpled-samples are most effective for reducing friction in comparison with smooth steel surfaces, improving the lubricating state from boundary to hydrodynamic region. Funded by the High Technology Research Project of Jiangsu Province (No. BG2007046), and the Productive Translation Item of College Scientific Research of Jiangsu Province Educational Office( No. JHB06-04)     

碳钢高温抗氧化涂料涂层的研究

用以氧化物为主要原料制成的醇基快干型涂料,涂敷于碳钢块上,点火块干使其固化形成涂层,防止碳饮氧化烧损.并采用失重法,对45#和T 10碳钢涂涂料的试样与裸样在高温下氧化失重进行了对比实验,分析了涂料对降低氧化烧损的影响以及涂料层的主要性能。实验表明,该涂料所形成的涂层在碳钢的加热过程中,与基体结合紧密,抗氧化性能以及耐热震性能较好,减少了碳钢高温氧化烧损,使碳钢在相同的加热温度和时间下,(如45#在6小时内100℃下),氧化烧损量由2.4~4.2g降低为0.8~2.5g,氧化速度由5.310×10-5g/mm2.h降低为3.885×1-0 5/mm2.h.     

35碳钢Cr-Ti共渗及Al-Ti共渗层的高温氧化行为

用循环氧化法测定了35钢Cr Ti及Al Ti共渗层的抗高温氧化性能.Cr Ti共渗层内侧富集的Ti以稳定的TiC形式存在,阻碍了表层富集的Cr向内层扩散,在700、800℃×96h条件下的抗高温氧化性能与0Cr18Ni9不锈钢接近.Al Ti共渗层内侧富Al,外侧富Ti.但经24h氧化加热后,Al、Ti元素的分布发生逆转,Al向表面富集,而Ti在渗层内侧富集并形成TiC,使氧化增重速率明显下降.如果以24h氧化加热后的氧化增重速率为比较标准,Al Ti共渗层在900℃×96h的抗高温氧化性能优于Cr Ti共渗.     

Ratcheting led surface failure of medium carbon bainitic steel under mild operation conditions

The behavior of rolling contact fatigue (RCF) of medium carbon bainitic back-up roll steel was investigated under its actual work conditions. A kind of asperity-scale surface originated cracks, which is lying parallel or at an acute angle to the surfaces, initiated after unidirectional plastic flow of the material in thin surface layer had occurred. Theoretical analysis indicates that they nucleate due to plastic ratcheting induced by asperity contact stresses, and consequently are named as ratcheting cracks. After nucleating and initially propagating, they arrest at some depth and resume propagating till about 70%-80% of the RCF failure life by initially turning parallel to contact surfaces. Their behavior of initiation and propagation is confined to a thin layer prior to the formation of surface distress. According to the critical principle of the preventive grinding strategy, removing the asperity influenced surface layer at about 70%-80% of the RCF failure life can effectively prevent the ratcheting cracks from developing into surface distress, which can lead to the formation of macro-RCF failure soon.     

中碳钢温变形过程的流变应力

为了制定中碳钢温轧工艺,利用Gleeble-3500热模拟试验机对中碳钢进行温压缩试验,研究其在不同变形温度(550～700℃)和应变速率(0.001～10s-1)下的流变行为,讨论温变形过程流变应力的影响因素。研究结果表明:中碳钢温变形过程由铁素体动态回复、铁素体动态再结晶、渗碳体球化和稳态变形4个阶段构成,其软化机理主要有铁素体动态再结晶和珠光体动态球化。     

Preparation and characterization of plasma Cu surface modified stainless steel

Cu modified layer was prepared on the surface of AISI304 stainless steel by plasma surface alloying technique.The effects of processing parameters on the thickness,surface topography,microstructure and chemical composition of Cu modified layer were characterized using glow discharge optical emission spectroscopy(GDOES),scanning electron microscopy(SEM)and X-ray diffraction(XRD).The experimental results show that the surface modified layer is a duplex layer(deposited + diffused layer)with thickness of about 26 μm under the optimum process parameters.The modified layer is mainly composed of a mixture of Cu and expanded austenite phase.The ball-on-disk results show that the modified layer possesses low friction coefficients(0.25)and excellent wear resistance(wear volume 0.005×109 μm3).The Cu modified layer is very effective in killing the bacteria S.aureus.Meanwhile,no viable S.aureus is found after 3 h(100% killed)by contact with the Cu alloyed surface.     

碳纤维增强摩擦材料的摩擦表面层

利用D-MS摩擦磨损试验机研究了碳纤维增强摩擦材料的摩擦磨损性能,并利用扫描电镜和能谱仪对其表面结构和微区成分进行了观察和测定,对热重分析试验的结果和摩擦磨损性能试验的结果进行了分析。结果表明:碳纤维摩擦材料在100～300℃内随温度升高摩擦磨损性能无明显降低,摩擦因数有所提高。碳纤维摩擦材料摩擦表面可分为富铁层、热力疏松层、变形强化层三层。摩擦表面工作层对材料表面获得稳定的摩擦磨损性能起重要作用。碳纤维的高导热性对材料的摩擦表面层结构有重要影响,它有利于减少热影响表面层深度,在本试验条件下,摩擦热影响表面层的深度约为0.55mm。