不同铬含量白口铸铁的抗小麦粉料磨粒磨损性能

利用模拟辊式制粉工况磨损试验机,对铬含量(质量分数,下同)分别为0,1.2%,4.0%的3种白口铸铁进行了小麦粉料磨损试验,研究了铬含量对白口铸铁磨损质量损失和磨损形貌的影响。结果表明:铬的添加能提高白口铸铁的抗小麦粉料磨损能力,铬含量为4.0%时,白口铸铁的磨损质量损失约为铬含量为0时的32%;随着铬含量的提高,白口铸铁被磨面的沟槽宽度与深度、棱脊峰谷值,以及金属元素含量均有所降低,但硬度显著增大,并且磨损表面的犁沟变浅变窄,犁沟两侧的犁皱变得不明显。     

M－B－A复相基体及M基体中铬铸铁湿态磨料磨损特性

着重对比探讨马氏体－贝氏体－奥氏体（Ｍ－Ｂ－Ａ）复相中铬铸铁和马氏体中铬铸铁的湿态磨料磨损特性。研究表明，冲击载荷、高应力湿态磨料磨损条件下（冲击功１．４７Ｊ，２．４５Ｊ），疲劳剥落是主要磨损机制，复相基体中铬铸铁的磨损速度低于马氏体中铬铸铁。而低应力湿态磨料磨损中显微切削是主要磨损机制，马氏体中铬铸铁的磨损失重低于复相基体中铬铸铁。     

24Cr高铬铸铁三体腐蚀磨损过程中腐蚀与磨损的交互作用

本文研究了24Cr高铬铸铁在弱酸性介质条件下,三体腐蚀磨损过程中腐蚀与磨损的交互作用,初步建立了解析模型。探讨了基体组织,含碳量与稀土元素在腐蚀与磨损交互作用过程中的作用。     

硬质颗粒复合合金的组织和耐磨性

本文强调基体合金组织对硬质颗粒复合合金耐磨性的决定作用,设计并通过“真空吸附铸件表面合金化工艺”,在灰铁铸件表层稳定地制得了以不同粒度的铸造碳化钨颗粒均匀分布于高合金铬钨白口铸铁中的复合合金。磨料磨损试验表明：基体合金组织对复合合金二体尤其是三体高应力磨损耐磨性有决定性的作用;以马氏体合金白口铁为基体合金的复合合金,在二体及三体磨损条件下均具有极高的耐磨性,铸造碳化钨颗粒愈粗,复合合金耐磨性愈高,当颗粒尺寸由140～200目增大到18～28目时,其在二体和三体磨损条件下的耐磨性分别是马氏体白口铁15Cr2Mo1Cu的9～31倍和2.8～6.7倍。     

以合金白口铸铁为基的硬质粗颗粒型复合合金耐磨性的研究

本文通过磨损分析后指出,要充分发挥颗粒型复合合金中硬质颗粒优异的抗磨能力,必须获得强硬质的粘结物组织来牢固地支持其硬质颗粒。在此基础上,通过表面合金化工艺,在灰铁表面上非常稳定地制得了一系列不同尺寸的铸造碳化钨颗粒,并均匀分布于铬钨合金白口铸铁中。磨粒磨损试验表明:粘结物组织对复合合金二体尤其是三体高应力磨损有决定性的作用;以马氏体合金白口铁为粘结物的复合合金在二体及三体高应力磨损条件下均具有极高的耐磨性,铸造碳化钨颗粒尺寸愈大,复合合金耐磨性愈高,当颗粒尺寸由140/200目增大到18/28目时,复合合金在二体及三体磨损条件下的耐磨性分别是马氏体白口铁15Cr2Mo1Cu 的9～31倍和2.8～6.7倍。     

铬系耐磨白口铸铁研究状况

介绍了国内外铬系耐磨白口铸铁的研究状况 ,阐述了高铬、低铬耐磨白口铸铁的应用现状 ,提出了在我国 Ni、Cr资源缺乏的情况下 ,研究中铬白口铸铁具有一定的现实意义。     

微合金化低铬稀土白口铸铁的研制和应用

本文研究微合金化低铬稀土白口铸铁的组织、性能和耐磨性表明,由于微量钼、钛和稀土合金的加入,使低铬白口铸铁硬度得到明显的提高,冲击韧性值也有所提高。生产表明,微合金化低铬稀土白口铸铁的生产成本低,工艺简单,耐磨性好。用其生产锤头,使用寿命是中锰白口铸铁的3～4倍。     

耐磨损及腐蚀的铸态28Cr白口铸铁

本文首先在销盘式二体磨损试验机上,使用二种不同硬度的磨料对三种基体状态的28Cr铸铁耐磨性进行了比较,结果表明具有铸态奥氏体基体的28Cr铸铁具有良好的耐磨性;进而在腐蚀磨损试验机上对铸态28Cr铸铁与马氏体15Cr1MolCu铸铁在不同PH值介质中的耐腐蚀磨损性能进行了对比,考察了在什么介质条件下28Cr铸铁取代15Cr铸铁才是合理的以及28Cr铸铁作为耐腐蚀磨损材料的成份选择原则。另外还对不同状态及成份的28Cr铸铁的机械性能进行了测定,为工程上的实际使用提供了依据。     

Fe-C-Cr-Mn亚稳奥氏体基铸造合金的摩擦磨损表层特性

研究了Fe-1.85C-8.03Cr-3.55Mn亚稳奥氏体基铸造合金的摩擦磨损表层特性，在较低的摩擦应力作用下，表层即可应变诱发α和ε马氏体。马氏体转变量随奥氏体形变量增加而增大，硬度也提高。由原奥氏体引起的表面硬度提高的原因：α和ε马氏体的形成；产生大量的位错和层错。在滑动磨损试验时，该合金的耐磨性高于25%Cr马氏体基白口铸铁。     

稀土铬合金白口铸铁的热塑性

对不同稀土含量低铬和高铬合金白口铸铁的可锻性。以及稀土对低铬和高铬合金白口铸铁热塑性的影响进行了研究。     

A study of sand slurry erosion of W-alloy white cast irons

This paper reports the results of a study into the effects of the composition, hardness and electrochemical properties of W-group cast irons on sand slurry-erosion resistance and wear mechanisms. The results indicate that the sand slurry-erosion resistance of the irons can be raised by increasing the content of tungsten, especially when the iron is alloyed with chromium. The relation between macrohardness and sand slurry-erosion is intricate. In the low hardness range, the sand slurry-erosion resistance is linearly increased with hardness, but this relationship does not exist in the high hardness range. The sand slurry-erosion resistance of cast iron can be considerably increased by increasing its corrosion resistance. Sand slurry-erosion is an abrasive wear process accompanied by corrosion and cavitation, all of which aggravate each other.     

低铬白口铸铁的组织与磨粒磨损性能

采用硅进行低铬白口铸铁的合金化，试验发现，随着硅含量增加，碳化物形貌由网状向断网状、分散孤立的条状转变；碳化物的含量增加，尺寸细化；碳化物硬度及材料的整体硬度也逐渐增加。在铬含量为59／5左右、硅含量〉2．5％时，碳化物出现了M7C3型，耐磨性也随着增加，该材料的抗冲击磨粒磨损性能最好的是下贝氏体组织。淬火温度和冷却方式对该类白口铸铁的抗冲击磨粒磨损性能影响不大。     

RESEARCH AND APPLICATION OF AS-CAST WEAR RESISTANCE HIGH CHROMIUM CAST IRON

ＲＥＳＥＡＲＣＨＡＮＤＡＰＰＬＩＣＡＴＩＯＮＯＦＡＳＣＡＳＴＷＥＡＲＲＥＳＩＳＴＡＮＣＥＨＩＧＨＣＨＲＯＭＩＵＭＣＡＳＴＩＲＯＮＬｉｕＪｉｎｈａｉＬｉｕＧｅｎｓｈｅｎｇＬｉＧｕｏｌｕＨｅｂｅｉＵｎｉｖｅｒｓｉｔｙｏｆＴｅｃｈｎｏｌｏｇｙＷａｎｇＫｕ...     

发动机气缸腐蚀磨损及其交互作用研究

为了分析研究柴油机气缸套工作过程中的交互作用,选用灰铸铁材料在硫酸腐蚀介质中进行磨损试验、腐蚀试验及腐蚀磨损实验,分析了腐蚀磨损交互作用图。结果表明：腐蚀介质促进交互作用,磨损及其磨损增量是材料腐蚀磨损的主体。     

Sliding wear of graphite crystallized chromium white cast iron

The effects of sliding velocity, heat-treatment and graphite shape on sliding wear of graphite crystallized chromium white cast iron were studied. Two types of graphite crystallized chromium white cast irons having flaky or spheroidal and another type of 2.6C–15Cr white cast iron were prepared for this study. The effect of sliding velocity on wear resistance was studied by the Okoshi type and pin-on-disk type wear tests on materials which have experienced “as cast” and “heat-treated” conditions. The Okoshi type wear test results are divided into two relationships depending on sliding velocity or distance. Two regimes, initial wear and steady-state wear, existed for wear loss and sliding distance. A characteristic form of wear curve with a peak and a minimum was obtained when correlating wear loss and sliding velocity. The wear resistance of graphite crystallized chromium white cast irons were superior to that of 2.6C–15Cr white cast iron. In the results of pin-on-disk tests, there was no clear difference in the reported wear loss and friction coefficient among the alloys. However, an opposite tendency has appeared in the wear loss and friction coefficient: the wear loss value reached a peak in the wear curve at 0.52 m/s, while the friction coefficient reached a minimum at 0.52 m/s.     

Widerstand gegen abrasiven verschleiss und dynamische bruchzähigkeit weisser vanadingusseisen

The wear behaviour under abrasive sliding loading, the structure and dynamic fracture toughness of white cast iron containing (4 – 6)% V are considered in this paper. In wear systems containing hard abrasive particles (silicon carbide), the dynamic fracture toughness and wear resistance increase with increasing austenite content in the structure. In systems with less hard abrasive particles (e.g. flint, garnet) these alloys exhibit a combination of high fracture toughness and high wear resistance. The vanadium-alloyed white cast irons with a predominantly austenitic matrix show more favourable values with respect to both dynamic fracture toughness and wear resistance in comparison with a simultaneously tested chromium white cast iron.     

Cr/C对含4%Ni高铬耐磨耐蚀铸铁组织的影响

文中利用金相显微镜、扫描电镜（SEM）,探讨了Cr/C对含4%Ni耐磨耐蚀铸铁组织的影响规律.试验结果表明：Cr/C是影响含4%Ni耐磨耐蚀铸铁组织中碳化物数量和形态的主要因素.无论是通过固定Cr,还是固定C来改变Cr/C,都可以大幅度调整组织中碳化物的数量和形态.当Cr含量固定时,随着Cr/C的增加,组织中碳化物数量减少,且由网状向断网状和孤立的条块状转变,冲击断口由脆性加韧性的混合型断裂过渡为韧性断裂;当C含量固定在较低水平时,随着Cr/C的增加,组织中碳化物数量急剧增加,碳化物形态由断网状和孤立的条块状向网状转变,冲击断口由韧性断裂过渡为脆性断裂,但当C含量较高（2.5%）时,随着Cr/C的增加,组织中的碳化物数量增加不明显,且碳化物均为网状结构.     

Influence of abrasive hardness on the wear resistance of high chromium irons

The resistance to abrasive wear was determined for a series of alloyed white cast irons in a high stress abrasion test which utilizes a specimen in sliding contact with bonded abrasives. These were conducted on silicon carbide, alumina and two sizes of garnet abrasive.The results indicate that the hardness, or type, of abrasive used in the test significantly influenced the wear rate of white irons, i.e. the rate of wear increased with increasing hardness of the abrasive. Also, the results indicate that the type of abrasive used in the test was a significant factor in ranking white irons for resistance to high stress abrasion. When tested on silicon carbide or alumina abrasive, as-cast austenitic irons exhibited lower rates of wear than heat treated martensitic irons; when tested on garnet, an abrasive of lower hardness, those irons with martensitic matrix microstructures exhibited the same or less wear than irons with austenitic matrix microstructures. It was also evident that heat treated irons with martensitic matrix microstructures exhibited varying degrees of resistance to abrasive wear depending on cooling rates and alloy content.     

The influence of surface oxidation on the wear resistance of cast iron

This paper reports a study of the influence of surface oxidation on the wear resistance of ductile iron, grey iron and vermicular iron during dry sliding friction. The mechanisms of wear are also reported. This study shows that the effect of surface oxidation (formed under normal atmospheric conditions) on the wear rate depends on the complex functions of graphite morphology and matrix structure. Generally the presence of surface oxidation decreases the wear rate of grey iron but increases the wear rate of ductile iron and vermicular iron when the cast iron has high hardness. This trend is reversed for low hardness cast iron.