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1.
稀土耐热蠕墨铸铁的试验研究   总被引:1,自引:0,他引:1  
采用稀土为主的含低沸点元素的蠕化剂生产了耐热蠕墨铸铁。研究了稀土耐热蠕墨铸铁的抗氧化、抗生长及热疲劳性能。结果表明,所研制的稀土耐热蠕墨铸铁具有优良的耐热性能  相似文献   

2.
低合金白口铸铁的稀土铝氮综合变质机理   总被引:3,自引:0,他引:3  
通过稀土铝氮综合变质处理使低合金白口铁中碳化物成为团块状,并使韧性显著提高。根据稀土、铝和氮三种变质元素分别及一同加入铁水后浇注成试样的物理冶金检测结果,讨论了各变质元素在熔体中的物化行为及这些行为对白口铸铁凝固的影响,尤其对碳化物结晶的影响。  相似文献   

3.
利用禄丰钢铁厂生产的磷铜钛低合金生铁,研制出磷铜钛低合金淬火铸铁球。该铁球用金属型铸造和余热淬火工艺,获得以马氏体+索氏体为主的基体组织,其耐冲击次数高于中锰铸铁球和低铬铸铁球,硬度HRC达52,是一种较为优良的磨球。  相似文献   

4.
针对天然碱制碱工业中设备的腐蚀问题,研制出五种成分的加稀土低合金铸铁材料,观察了材料的石墨形态,分析了材料的金相组织,并通过XRD确定其基体组织。在此基础上,采用布氏硬度计对其硬度进行测试,利用静态失重法测试其腐蚀速度,并对其耐碱腐蚀性能进行评价。借助扫描电镜观察材料的腐蚀产物形貌并通过能谱仪进行元素含量分析,讨论了加稀土低合金铸铁在烧碱液中的耐碱腐蚀机理。结果表明,加入适量的稀土合金可以提高合金铸铁的耐碱腐蚀性能;加稀土低合金铸铁的腐蚀产物层越致密,耐碱腐蚀性能越好,稀土含量为0.06%的RD3试样的腐蚀产物层较致密,表现出较好的耐碱腐蚀性能。  相似文献   

5.
稀土对高镍铬白口铸铁组织形态的影响   总被引:3,自引:0,他引:3  
在轧辊用高Ni—Cr铸铁中添加不同量的稀土,研究了稀土对这种高合金白口铸铁中石墨、碳化物的分布形态以及基体组织的影响。试验表明:加入适量稀土后,碳化物由原来的连续网状过渡到断续网状、岛块状,基体中石墨的分布变得均匀且降低了石墨片两端的尖锐程度故而提高了材质的使用性能。  相似文献   

6.
低合金白口铸铁是一种耐磨性能优良的铸铁材料,但其组织中共晶碳化物呈连续网状分布,削弱了基体的连续性,导致铸铁脆性过大。我们探讨了复合变质处理和热变形处理对共晶碳化物团球化的影响,同时还研究了共晶碳化物团球化对低合金白口铸铁机械性能和耐磨性的影响,结果表明,共晶碳化物团球化有利于白口铸铁韧性和耐磨性的大幅度提高。  相似文献   

7.
本文采用氧化增重及氧化层厚度两种试验疗法和参数,探讨了稀土对铸铁在600℃、700℃时抗氧化性的影响。研究结果表明:稀土元素改善铸铁抗氧化性能的机制在于残留在铸铁中的稀土改变了石墨形状及分布特征,而不是通过合金化改变氧化膜的结构和组成。在灰铸铁中,随片状石墨的细化,D型石墨数量的增加,抗氧化性得到改善。而蠕墨铸铁的抗氧化性能与其蠕化率有着密切的关系。试验发现在含碳量相同时,高蠕化率的蠕墨铸铁抗氧化性能优于A型片状石墨铸铁,而劣于D型石墨铸铁。  相似文献   

8.
为了合理利用稀土资源中随着钕、铈的大量提取和应用后所得的副产品富镧混合稀土金属,本文直接在直流矿热炉中用碳热还原法制备富镧基稀土硅铁合金,并利用所制备的富镧稀土硅铁合金作为蠕化剂来制取蠕墨铸铁.主要研究了富镧稀土硅铁合金的加入量对铸铁中石墨形态和组织的影响.结果证明,用富镧基稀土蠕化剂,通过控制适当的工艺条件,能够得到蠕墨铸铁和球墨铸铁.  相似文献   

9.
《稀土》1980,(4)
山东省机械工业厅受一机部委托,于1980年12月9日—11日在济南召开了“用冲天炉熔制稀土蠕墨铸铁”鉴定会。参加会议的有领导机关、大专院校、科研单位、工厂等35个单位,共42名代表。会议对稀土蠕墨铸铁的熔炼工艺、稀土锌镁蠕化剂熔炼工艺、稀土蠕墨铸铁的机械加工性能、耐磨性能、铸造性能、铸件的钢性等方面进行了鉴定。并参观了济南材料试验机厂的现场操作表演。  相似文献   

10.
高温下奥—贝蠕铁的组织与性能   总被引:1,自引:0,他引:1  
奥—贝蠕铁是继奥—贝球铁之后发展起来的新型工程材料之一,也是世界上正在开发的材料。本文系统地提供了奥—贝蠕铁的制取工艺,奥—贝蠕铁的组织特征及其在常温及随温度提高力学性能变化的规律。研究表明,以稀土硅铁为蠕化剂,所制取的蠕化率大于90%、基体以铁素体为主的蠕墨铸铁,经等温淬火后,可稳定地获得奥氏体—贝氏体基体(以下简称奥—贝蠕铁),它有较好的综合性能,在常温下σb=820~937.5MPa,δ=0.40%~0.78%;在600℃时,σb=158~187MPa,δ=4.00%~7.84%,仍超过HT150的常温性能。当低于300℃时组织和性能稳定性较好,是适宜的工作温度范围  相似文献   

11.
EfectofRareEarthElementsonCarbideMorphologyandPhaseTransformationDynamicsofHighNiCrAloyCastIronYangQingxiang(杨庆祥),LiaoBo(廖波...  相似文献   

12.
采用扫描电镜分析,硬度测试和摩擦性能测试等手段,研究了稀土对低合金耐磨铸钢组织和性能的影响。结果表明,在低合金耐磨铸钢中添加0.15%稀土,可细化合金铸态组织,增加铸态组织中的铁素体数量,减少珠光体数量,同时可细化热处理后合金的贝氏体组织,使铁素体形态和大小分布均匀,马氏体数量减少。添加稀土后可使铸态合金硬度提高9.4%,摩擦系数由0.136 9减小为0.081 9。  相似文献   

13.
The addition of rare earth element yttrium played an important role in the improvement of both mechanical properties and wear resistance of Al2O3/(W,Ti)C ceramic cutting tool material.Mechanical properties especially the fracture toughness and flexural strength were obviously increased when a suitable amount of the yttrium were added.Wear resistance of the developed rare earth ceramic cutting tool material was higher than that of the corresponding materials without rare earth in the machining of the hardened 45# carbon steel and cast iron HT20-40.Wear modes of the Al2O3/(W,Ti)C rare earth ceramic tool materials were mainly flank wear and crater wear accompanied with slight notch wear when machining the hardened carbon steel.Wear mechanisms were major abrasive wear at low cutting speed and adhesive wear at high cutting speed.Wear modes were nearly the same except that the adhesion phenomenon in the crater area was intensified when machining cast iron.The flank wear area was relatively smooth with no obvious plowing phenomenon which was possibly concerned with the workpiece of low hardness and the adhesion phenomenon at high cutting temperature.  相似文献   

14.
本文综述了国内外稀土在白口铸铁领域研究和应用情况,稀土能有效地改善白口铸铁组织与性能,白口铸铁是稀土在铸铁中应用的重要领域之一,有广阔的应用前景。稀土最佳的加入量、处理工艺、稀土对白口铸铁作用机理方面,都进行了不少工作,但还有不少问题有待于投入更大的力量进行更深入的研究。  相似文献   

15.
Withhigherhardnessandbetterwearresistance ,whitecastironscanbeusedaswearresistantpartsinmanyfields .Inpractice ,thewearresistantpartsareoftenrequiredtobesubjectedtogrindingofabrasivesandrepeatedimpactaction .Therefore ,fatiguecracksareliabletobegeneratedo…  相似文献   

16.
The flux cored wires with different amounts of rare earth (RE) oxides additions for hardfacing (harden-face-welding) the workpieces of high chromium cast iron were studied in this work.The morphology of carbides in hardfacing metal was observed,and the type of the carbides was determined by optical microscopy,scanning electron microscopy (SEM),energy dispersive spectrometer (EDS) and X-ray diffraction (XRD).Based on the data of effect of RE on carbides morphology,the refined reason for carbide by RE oxide was discussed with the misfit theory.The results showed that,the microstructure of hardfacing metal was composed of martensite,residual austenite and M7C3 carbides.With the increasing amount of RE oxide additions,the volume fraction and roundness of the carbides were increased,however,the area and perimeter of carbides were decreased.It indicated that carbides in hardfacing metal could be refined and spheroidized by adding RE oxides in flux cored wires.  相似文献   

17.
摘要:从耐磨铸铁的分类、发展历程、现行标准、性能特征、磨损性能影响因素、典型应用等方面论述了国内外耐磨铸铁的研究现状与进展,重点介绍了化学成分、基体组织、热处理工艺和碳化物对耐磨铸铁磨损性能的影响,提出了耐磨铸铁存在韧性低、成本高等问题,以及低成本无镍化,建立理论模型,ZrO2作为形核剂,新型复合碳化物等今后研究方向的建议。  相似文献   

18.
设计了新型低合金白口铁的显微组织和化学成分,研究了稀土复合处理与热处理对其组织和性能的影响,试验结果表明,它具有良好的综合机械性能。此外,还地PH=6的弱酸性砂浆冲蚀磨损机理进行了初步的探讨。  相似文献   

19.
An apparatus of zone melting unidirectional solidification with a steep temperature gradient andan impact fatigue tester were used.The effect of RE elements on the morphology of carbides and the impactfatigue properties of the low Cr white cast iron were investigated.Experimental results showed that the modi-fying effect of RE elements was remarkable on the M3C carbides.With the addition of RE elements in thelow Cr iron,a lot of plate-like carbides were transformed into lath-like and rod-like ones.The higher thecontent of RE elements was,the more was the fraction of the lath-like and rod-like carbides.In the low Crwhite cast iron,the RE modifying agent can efficiently increase the impact fatigue resistance and decrease thecrack growth rate and delay the time of incipient cracking.With the increase of the content of RE elements inthe low Cr cast iron,the impact fatigue resistance increased greatly and the crack growth rate decreased rap-idly.  相似文献   

20.
Itisnoticeablethatthelowchromiumsemi steelhashighhardnessandabrasionresistance[1] .However,thematerialhaslowductility ,owingtothereticulatedistributionofcarbide ,whichrestrictsitsapplications .Therefore ,itisnecessarytoim provethecomprehensivepropertiesforpotentialap plications .Thecomprehensive propertiesoflowchromiumsemi steelcanbeimprovedbyaddingrareearths (RE)becauseREcanchangethemorphologyofcarbideandnon metallicinclusions ,refinegrainsize,purifyandstrengthen grainboundaryandsoon[2 -5] …  相似文献   

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