加硼高铬铸铁

从降低成本和提高耐磨性的角度出发 ,对高铬铸铁进行了加硼的试验研究。考察了加硼量和热处理工艺对高铬铸铁的硬度和冲击韧性的影响 ,并进行了销盘磨损试验。实验结果表明 :只要添加适量的硼和采取合适的热处理工艺 ,可以使高铬铸铁的碳化物细化 ,基体淬透性增加 ,并使高铬铸铁的硬度和韧性同时得到提高 ,从而增加了材料的耐磨性。     

硼铸铁加硼新工艺探讨

硼铸铁作为一种优良的耐磨合金,已被广泛的用于制造各种耐磨件。现行硼铸铁加硼工艺大多为炉内投入B—Fe合金。由于B—Fe合金价格较贵,来源困难,因此,生产硼铸铁的厂家都在研究硼铸铁加硼工艺的新途径。近年来利用天然硼矿石熔制硼铸铁取得成功。这种加硼工艺虽然可以大幅度降低成本。但是,由于硼矿石在开采、运输等方面还存在问题,而且这种硼矿石又是生产硼酸、硼砂的主要原料,所以使该工艺的推广应用受到限制。日前,国内市场出现一种新材料一含硼生铁,价格较便宜,来源丰富,是铸造行业生产铸铁的理想材料。对此,我们进行了试验。含硼生铁的块度及重量与普通铸铁相同,断口呈白口,硬度较高。其含硼量为1％。它是东北工学院和丹东风城钢铁厂联合研制的新产品。是由硼镁铁矿研制而成。该工艺可直接用高炉分离硼铁,为含硼耐磨合金的生产又开辟了一条新途径。1.试验条件     

锻造高铬铸铁的组织和性能

本文对高铬铸铁进行单向拔长热塑性变形试验,研究了锻造比(K_L)为1～4.14的高铬铸铁的组织、机械性能和抗磨料磨损性能。结果发现随着K_L增大,碳化物分布越来越均匀、孤立和细化;抗弯强度、冲击韧性及抗磨料磨损能力明显提高,而硬度变化不大。     

感应炉熔炼高铬铸铁操作要点

高铬铸铁件的化学成分不合格、夹杂、热裂和晶粒粗大等铸造缺陷与其铁液的质量密切相关。尤其是采用感应炉熔炼的铁液,其质量更难达到高标准。 笔者对缺陷产生的原因进行了仔细分析,并经过大量试验,摸索出了一套既简便易行,又能大幅度提高铁液质量的工艺操作规程,并在数家工厂     

27%Cr高铬铸铁组织及性能研究

对不同碳、钼含量的27％高铬铸铁的组织、硬度及耐磨性等进行了试验。结果表明：高铬铸铁的淬火硬度及抗磨料磨损能力随含碳量增加而提高。但当铬、碳含量比低于7时,宏观硬度降低。钼对改变大量析出奥氏体的临界含碳量有一定影响,铬、碳含量比低于7时,加钼量不应低于2％。无论含钼或不合钼,过共晶高铬铸铁（3．7％C）抗磨料磨损能力均优于亚共晶高铬铸铁,冲击韧度与后者相近。     

锰硼奥氏体基高铬铸铁的组织结构及抗磨性研究

研究了四种不同含B量的Fe-Cr-Mn-C-B系铸造合金的铸态组织结构及摩擦磨损特性。结果表明：硼碳化物体积分数随B含量增加而增大，并可按等量原子比估算。由于含B合金基体表面更易摩擦诱发马氏体相变，且产生表面细晶强化作用，显著提高了滑动磨损的抗磨性。含硼0．3％时，滑动磨损的抗磨性是25Cr马氏体基合金的4倍，是Mnl3铸钢的7．6倍。     

应用火焰法熔接高铬铸铁和钢的过程（下）

应用火焰法熔接高铬铸铁和钢的过程（下）四、结论当对熔接过程中的溶解及合金相的析品现象进行研究时．如果有与析晶系同系的Ｆｅ—Ｃｕ—Ｃｒ—Ｃ四元状态图．则是最理想的。但由于找不到这种状态图。只好利用Ｆｅ—Ｃｕ—Ｃ三元状态图进行讨论分析。本项研究主要是选用...     

陶瓷刀具切削高铬铸铁切削用量的优化计算

考虑刀具动态强度条件下,对用陶瓷刀具加工高铬铸铁的切削用量进行了优化计算,从而为用陶瓷刀具经济性地加工高铬铸铁提供了理论依据。     

微波消解ICP-AES法测定高铬铸铁中多种元素

高铬铸铁中C和Cr的含量均较高,分析测定其化学成分时,采用常规化学酸溶法分解试样非常困难,而采用微波消解法分解样品,用电感耦合等离子体原子发射光谱法(ICP-AES)检测高铬铸铁样品中多种元素含量,其精密度和准确度能够满足科研、生产的需要。     

稀土变质高铬锰钛铸铁的研探

火电厂球磨机用金属磨球和衬板,一方面受煤的高应力犁削磨损;另一方面受小能量多次冲击。因而,要求具有一定的耐磨性、韧性和强度。目前国内火电厂球磨机磨球等广泛采用45号钢和高锰钢制造。其使用周期短,更换频繁。据测,火电厂中仅制粉系统,每年钢球磨耗达10万吨以上。为此,我们立足于国内,在实验室试制成高铬锰钛铸铁。采用以锰代钼来提高铸铁的淬透性获得马氏体,加入钛铁以提高硬度和强度,并     

The particle size effect on abrasive wear of high-chromium white cast iron mill balls

Granite grinding tests, under dry and wet conditions, were performed to assess the influence of abrasive particle size to the wear behavior of martensitic high-chromium white cast iron mill balls. The tests were performed, at first, using raw granite particle sizes between 0.074 and 19.1 mm, and then with coarse and fine granite fractions obtained after screening the raw granite in a 3.36 mm sieve. It is demonstrated that the relative particle/ball size relationship is the determining parameter to ball wear. The highest ball wear rates were observed for fine granite grinding under dry (120 mg/cycle) and wet (129 mg/cycle) conditions. The lowest wear rate (ca. 50 mg/cycle) was observed for coarse granite grinding (dry and wet). These different results were attributed to the different size relationships between grinding body diameter and granite particles size. For wet-grinding of raw granite, the mineral components may influence significantly the wear behavior. Feldspar can act as a bonding agent, gluing fine quartz particles to the coarse granite and to the balls surface and turning the dependence of the relationship between the relative sizes of ball and granite particle less important to the wear process. This explains why wet-grinding of raw granite results in a ball wear two times greater (106 mg/cycle) than dry-grinding (51 mg/cycle).     

The wear behaviour of high-chromium white cast irons as a function of silicon and Mischmetal content

The sliding wear behaviour of high-chromium white cast iron (16.8% Cr) has been examined as a function of silicon and Mischmetal alloy additions (1, 2, 3 and 5% Si and 0.1 and 0.3% Mischmetal). Such additions are known to modify the structure, but there is considerable controversy as to the exact effect. Silicon was found to refine the dendritic structure and increased the eutectic carbide volume fraction. However, for contents above 3%, transformation of the austenitic matrix to pearlite occurred in preference to martensite. Mischmetal additions reduced the austenite dendrite arm spacing, but did not have a significant effect on the carbide structure. The wear behaviour was investigated for each alloy in the as-cast (austenitic matrix) and hardened (martensitic) conditions using a block on ring configuration in pure sliding in the load range 42–238 N for a distance of 70 km against a hardened M2 steel counterface. For low loads (42 and 91 N), all the alloys showed a similar wear rate (3×10⁻⁴ to 4×10⁻⁴ mm³/m), associated with the formation of a thin (3 μm) oxide film of Fe₂O₃, the formation of very fine debris and a small depth of deformation below the worn surface (7 μm). For higher loads, wear was a strong function of microstructure, and was associated with a thicker film of the oxides Fe₂O₃ and Fe₃O₄ and greater depths of deformation. The iron with 2% silicon exhibited the best performance with a wear rate of 7×10⁻⁴ mm³/m and this was attributed to its finer structure and the formation of a thicker oxide film. In contrast, the iron with 5% silicon exhibited the worst performance, with a wear rate of 14×10⁻⁴ mm³/m, attributed to the pearlitic matrix. A linear relationship was observed between the depth of carbide fracture and the wear rate. The relationship between microstructure and wear mechanism is discussed.     

铸铁阀门耐腐蚀性能的分析

阐述了铸铁的腐蚀机理及特点，分析了铸铁与铸钢阀门在海水中的腐蚀速度，介绍了孕育铸铁加合金后抗腐蚀能力及镍铬铸铁工况运行情况。     

球磨机用高铬铸铁球的变质处理工艺研究

在高铬铸铁球中加入不同的稀土元素进行变质处理,再进行性能检测分析,结果表明：加入0．3％的硅并经热处理后可以显著提高铸铁球的性能。     

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.     

MPS（MBF）型中速磨煤机用高铬白口铸铁磨辊的研制

在分析ＭＰＳ（ＭＢＦ）型中速磨煤机用磨辊的工况条件和性能要求的基础上，结合国内资源，设计确定了材料的成分组成，制定了合理的铸造、热处理工艺，成功地研制了适合我国煤质特点的高铬白口铸铁磨辊．试验运行结果表明，同样工况条件下，所研制的高铬白口铸铁磨辊的耐磨寿命比进口镍硬Ｎ＃铸铁提高５０％以上，且成本降低，经济效益十分可观．     

冲天炉熔炼耐热球墨铸铁RQTSi5

介绍用耐热球铁（RQTSi5）代替RTCr0．8耐热铸铁生产水泥窑冷却机扬料板的生产条件和工艺技术。     

An investigation on machinability of nodular cast iron by WEDM

In this study, the machinability of standard GGG40 nodular cast iron by WEDM using different parameters (machining voltage, current, wire speed, and pulse duration) was investigated. From the results, the increase in surface roughness and cutting rate clearly follows the trend indicated with increasing discharge energy as a result of an increase of current and pulse-on time, because the increased discharge energy will produce larger and deeper discharge craters. Three zones were identified in rough regimes of machining for all samples: decarburized layer, heat affected layer, and bulk metal. High machining efficiency can be obtained when the proper electrical parameters are selected, but whether high energy or the low energy is used, a coarse surface is always obtained. The variation of surface roughness and cutting rate with machining parameters is mathematically modeled by using the regression analysis method.     

离心铸造合金白口铸铁轧辊的研究

应用离心铸造方法,研制CrMoWVNb白口铸铁轧辊。分析合金元素在轧辊中的作用及裂纹产生原因,提出了消 除裂纹措施并应用于高速线材轧机预精轧机架,使用寿命达到高镍铬无限冷硬铸铁轧辊的4～5倍。     

白口铸铁电火花表面强化研究

白口铸铁常被用于要求耐磨的工作表面,改善白口铸铁表面的耐磨性具有现实应用价值.利用金相分析、X射线衍射分析及显微硬度和耐磨性测试等手段,对白口铸铁表面进行电火花强化所得强化层的性能进行了研究,结果表明对白口铸铁进行电火花强化可以赋予其表层更高的硬度和更好的耐磨性.