40Cr的冲蚀磨损性能研究

在自制的转盘式冲蚀磨损试验台上以45^#钢为对比材料，对40Cr的冲蚀磨损性能进行了试验研究，结果显示40Cr的冲蚀磨损规律与45^#钢基本相似，而耐冲蚀磨损性能比45^#钢稍强。在电子显微镜（SEM）下对40Cr和45^#钢冲蚀磨损表面形貌进行观察，分析表明：40Cr和45^#钢的冲蚀磨损机制都是硬质砂粒对材料表面的微切削作用。     

QT500的冲蚀磨损试验研究

在自制的转盘式冲蚀磨损试验台上以灰口铸铁（HT200）为对比材料，对球墨铸铁（QT500）的冲蚀磨损性能进行了试验研究，结果显示QTS00的冲蚀磨损规律与HT200基本相似，而耐冲蚀磨损性能比HT200稍强。在电子显微镜（SEM）下对QTS00和HT200冲蚀磨损表面形貌进行观察，分析表明：QTS00的冲蚀磨损机制是硬质砂粒对材料表面的微切削作用，而HT200的冲蚀磨损机制是因赫兹裂纹导致的脆性脱落。     

离心泵叶轮材料HT200的空蚀磨损机理研究

在圆盘式磨蚀试验台上，对HT200和45^#碳钢进行了模拟实际工况条件下的空蚀磨蚀实验，用失重法评价了两种金属材料的抗空蚀磨损性能，并用扫描电镜观察了空蚀试件表面形貌，试验结果表明：45^#碳钢的抗空蚀性能远要比HT200灰铁好；空蚀的本质是由微射流对试件表面的冲击而产生的低周疲劳过程；从摩擦学设计的角度考虑，45^#碳钢和灰铸铁HT200都不适合选为叶轮材料。     

冲蚀速度对40Cr材料抗冲蚀性能影响的研究

对40Cr及对比材料45#钢进行冲蚀磨损模拟现场试验,研究了冲蚀速度对冲蚀磨损的影响规律,结合微流边界层理论,分析了冲蚀速度对冲蚀磨损量的影响,推导了冲蚀速度与磨损量的数学关系式。结果表明:冲蚀速度U与磨损量W呈指数关系,随着U地增大,W也相应地增加,40Cr材料对应的指数n是2.3。     

40Cr冲蚀与空蚀交互磨损试验研究

对40Cr进行模拟化工泵叶轮流道内工况条件下的冲蚀与空蚀交互磨损试验,分析40Cr材料的抗交互磨损性能和冲蚀与空蚀交互磨损试件表面磨痕。结果表明:40Cr的冲蚀与空蚀交互磨损失重曲线分为孕育期、上升期、衰减期和稳定期。在孕育期中,材料失重量很小;在上升期中,材料的冲蚀与空蚀交互磨损失重量增加。40Cr材料的交互磨损特性是以微切削、犁削和脆性剥落为主,同时存在针眼和剥落坑。40Cr试样表面的冲蚀沟槽和空蚀坑主要沿水流线速度矢量的方向,但也存在一些与线速度成一定夹角的摩擦痕迹或沟槽,说明影响冲蚀与空蚀交互磨损的因素不仅是水流速度,还与沙粒运动轨迹、水流方向及冲蚀角度等有关。     

聚氨酯/TiO2纳米复合材料冲蚀磨损特性研究

以纳米TiO2作为填料,制备耐磨蚀聚氨酯纳米复合材料.用相对抗磨损性法评价了聚氨酯纳米复合材料的冲蚀磨损性,通过扫描电镜观察聚氨酯纳米复合材料的磨损形貌,尝试解释纳米TiO2增强聚氨酯复合材料抗含沙冲蚀磨损性能的机理.试验结果表明,纳米粒子均匀分散于聚氨酯中,使聚氨酯弹性体耐磨蚀性得以提高.聚氨酯/TiO2纳米复合材料的抗冲蚀磨损性能分别是45#钢的10.67倍,2Cr13钢的6倍,纯聚氨酯的1.28倍,TiN/聚氨酯复合材料的1.09倍.     

含沙量和沙粒粒径对QT500材料冲蚀磨损特性的影响

利用圆盘式磨蚀试验装置模拟流体机械工况条件,对QT500和45钢进行了冲蚀磨损试验,用失重法研究了材料在不同含沙量和沙粒粒径时的冲蚀磨损特性。对试样表面微观形貌进行了观察,探讨了材料的冲蚀磨损机理和损伤规律。研究表明：随含沙量的增加,材料的磨损率也增加,但不与含沙量的增加值成正比;随沙粒粒径的增大,磨损量亦增加。QT500的冲蚀磨损机理主要是脆性剥落和疲劳破坏。     

苜蓿草粉对不同金属材料的磨损试验

选用与环模制粒工况相似的磨料磨损试验机,以甘农三号紫花苜蓿为磨料,对4种金属材料进行磨料磨损试验。利用扫描电镜对试样摩擦表面的磨损形貌进行了观察研究,探索苜蓿草粉对金属材料的主导磨损机制。结果表明:4种材料的磨损率和磨损系数由小到大依次为3Cr13、9SiCr、45号钢、HT200;苜蓿草粉磨料对45#、9SiCr的磨损机制以显微切削和粘着磨损为主;材料的硬度、塑性、韧度和材料的显微结构组织对金属材料耐磨性有较大的影响,同时金属硬度本身与耐磨性不成正比。此研究对降低制粒机的制造成本和使用成本具有实际指导意义。     

碳钢奥氏体不锈钢材料在水电工程中应用的局限性

通过对水电站典型应用材料(55钢、1Cr18Ni9Ti、0Cr13Ni5Mo)在冲蚀磨损过程中电化学腐蚀及抗冲蚀磨损性能研究,区分出纯磨损、纯腐蚀、磨损对腐蚀的促进分量及腐蚀对磨损的促进分量等在材料失效过程中各占的比例,考察了试验材料的抗冲蚀磨损特性及其磨损与腐蚀间的交互作用,分析了其失效机制。结果表明:不同的冲蚀速度下,0Cr13Ni5Mo不锈钢的冲蚀磨损失重率最小,55钢最大;纯磨损是材料失去的主要方式:55钢虽然纯磨损量较小,但腐蚀及其磨损与腐蚀的交互作用失去量大,1Cr18Ni9Ti不锈钢虽然纯腐蚀量小,但纯磨损量大,因而都有应用的局限性。     

固液两相流泵叶轮用Cr26高铬铸铁的冲蚀率模型及影响因素

采用正交试验方法对Cr26高铬铸铁进行了冲蚀试验,基于冲蚀率理论计算模型对试验数据进行多元非线性回归,得到了Cr26高铬铸铁的冲蚀率计算模型并进行了验证;通过试验和模型计算对冲蚀率随其影响因素的变化规律进行了定量描述。结果表明:所建立的Cr26高铬铸铁冲蚀率计算模型具有较高的准确性;冲蚀率随冲蚀角度的增大先增大后减小再略微增大,最大冲蚀率出现在冲蚀角度40°附近,在低冲蚀角度下磨损形式以切削磨损为主,在高冲蚀角度下磨损形式以变形磨损为主;随着固体颗粒粒径的增大,冲蚀率增大,切削磨损占比增大,变形磨损占比减小;随着冲蚀速度的增加,切削磨损占比减小,变形磨损占比增大。     

不同润滑介质下GCr15/45#钢摩擦磨损特性的研究

利用DELTALAB-NENEDS20型高精度液压式微动试验机在干摩擦、水润滑和油润滑等条件下，对GCr15／45#钢进行了微动磨损实验，研究了润滑条件对GCr15／45#钢对摩时的摩擦学性能的影响，并利用激光共焦显微镜对45#钢的磨损表面进行了观察和分析。结果表明润滑介质可以降低摩擦副摩擦因数和45#钢的磨损量；材料的磨损机制也随着润滑条件的不同发生了相应的变化。     

Corrosion–erosion wear behaviors of 13Cr24Mn0.44N stainless steel in saline–sand slurry

The corrosion–erosion wear behaviors of austenitic stainless steels, 316L and 13Cr24Mn0.44N, were investigated in water–sand slurry and saline–sand slurry, respectively. The corrosion–erosion wear mass-loss was measured to evaluate the influence of medium and materials. The worn surface and corrosion–erosion wear mechanism were analyzed using a scanning electron microscopy and a non-contact optical profilometer. Results show that the corrosion–erosion wear mass-loss of 13Cr24Mn0.44N is lower than that of 316L in both the slurries. The relative wear resistance increases with the increasing of the impingement velocity and arrives at maximum of 1.6. The dominant wear mechanism of 13Cr24Mn0.44N is abrasive wear in the water–sand slurry, whereas it becomes abrasive wear associated with little corrosive pitting in the saline–sand slurry. As the impingement velocity increased all the synergism ratios exhibit a tendency of increase, among which the synergism ratio of 13Cr24Mn0.44N is always lower than that of 316L at any given velocity. The results indicate that 13Cr24Mn0.44N possesses a predominant anti-corrosion–erosion wear property.     

Relations between oxidative wear and Cr content of steels

Dry sliding wear tests at 25-400 °C were performed for 45, 4Cr5MoSiV1 and 3Cr13 steels; the relations between oxidative wear and Cr content of steels were explored. The low and medium-Cr steels had a substantially lower wear rate and increasing tendency than the high-Cr steel at 25-200 °C, but the contrary case occurred at 400 °C. With an increase of ambient temperature, the wear rate of the low and medium-Cr steels first decreased, then increased and reached the lowest value at 200 °C, while the wear rate of the high-Cr steel decreased monotonously with the lowest value at 400 °C. At 25 °C, trace tribo-oxides reduced wear to some extent in adhesive-dominated wear for the low and medium-Cr steels. At 200 °C, a small amount of tribo-oxides formed and reached a thickness of 10 μm on contacting asperities in the low and medium-Cr steels, thus oxidative mild wear prevailed. At 400 °C, a great amount of tribo-oxides appeared in the low and medium-Cr steels; unexpectedly, the high-Cr steel had more tribo-oxides than the low or medium-Cr steels in some cases. Its high wear resistance may be attributed to Cr-strengthened adhesion power of tribo-oxides and matrix.     

不同热处理条件下45#钢与40Cr钢摩擦学性能比较

针对机械行业中45^#钢和40Cr钢使用混乱的状况,着眼于2种钢材的基础性能,从45^#钢和40Cr钢的耐磨性能入手,对二者在不同热处理条件下的摩擦学性能进行了研究和比较。结果表明：在调质处理状态下,45^#钢和40Cr钢与GCr15钢对磨时的摩擦因数基本相同,但45^#钢的磨损量要低于40Cr钢,在强度符合条件,工件形状不太复杂的情况下,建议采用45^#钢;在淬火加低温回火处理状态下,45^#钢的摩擦因数与磨损量均高于40Cr钢的摩擦因数。在强调工件的强度和耐磨性时,建议采用40Cr钢;在高频淬火加低温回火处理和在离子氮化处理状态下,45^#钢的摩擦因数与磨损量均接近于40Cr钢的摩擦因数与磨损量,在保证强度的情况下,可以考虑采用45^#钢以降低生产成本。     

高压流体入射角对节流阀材料的冲蚀预测及验证

针对钻井作业中高压流体携带的固相颗粒高速撞击阀芯曲面,导致阀芯轮廓冲蚀严重及节流阀使用寿命缩短这一技术性难题,运用欧拉-拉格朗日法和离散相模型,预测了颗粒在不同入射角度下对40Cr钢的冲蚀磨损量、冲蚀速率和冲蚀形貌分布,并将其与相关实验进行了对比。对比结果表明：当粒子入射角由15°增大到90°时,预测冲蚀斑坑深度、冲蚀质量损失和冲蚀速率先增大、再减小,冲蚀表面形貌由椭圆形逐渐向圆形变化;当粒子入射角为45°时,材料质量损失达到最大。因此,在进行节流阀的优化设计时,应尽量避免粒子入射角为45°以减缓粒子对阀芯的冲蚀。     

Effect of alloying additives on impact-abrasive wear of manual arc welded hadfield steel hardfacings

The results of studying the impact-abrasive wear of manual arc welded Hadfield steel hardfacings and this steel alloyed with Cr, Ni, Mo, B, Cu, and Si, both without and with coarse-grained tungsten carbide reinforcement, are presented. It has been found that under conditions of impactless wear the presence of the hardening phase in the Hadfield steel increases its wear by 40% on average compared to the wear of the base and alloyed Hadfield steels. With an increase in the impact energy from 2.8 to 5.6 J, the wear of the reinforced Hadfield steels decreases and becomes comparable with the wear of the base and alloyed Hadfield steels. Under the conditions of erosion by coarse particles, layers of the Hadfield steel reinforced by tungsten carbide have slightly lower wear rate than unreinforced ones.