奥氏体中锰钢的磨料磨损性能

在ML-100型销-盘式磨料磨损试验机上,通过不同钢种之间的对比试验,研究了奥氏体中锰钢（BTW钢）石英砂磨料及煤矸石磨料下的磨损性能,并采用SEM分析了其磨损机制。结果表明,在高硬度的石英砂磨料中,BTW钢加工硬化明显,有效硬化层深度达900 μm,耐磨性能优于其他钢种,而在质地较软的煤矸石磨料中,其耐磨性降低;BTW钢在不同磨料下的磨损机制均为犁削,但形貌差异较大,石英砂磨料下磨损表面较为均匀,犁沟深度较浅、宽度较窄,脊缘部分较薄,脊缘在反复磨损中断裂成屑的数量较多,而煤矸石磨料中,犁沟存在于整个磨损表面且变形较小,几乎没有发现切削存在。     

奥氏体化温度对中碳低合金耐磨钢组织和耐磨性的影响

研究了奥氏体化温度对中碳低合金耐磨钢组织与耐磨性的影响。结果表明,在900℃奥氏体化温度下,通过中断空冷淬火处理,试验钢的显微组织为下贝氏体/马氏体复相组织,此时试验钢具有较好的强韧性配合及最佳的耐磨性。     

TiC-Maraging stainless steel composite： microstructure, mechanical and wear properties

Particulate TiC reinforced 17-4PH and 465 maraging stainless steel matrix composites were processed by conventional powder metallurgy （P/M）. TiC-maraging stainless steel composites with theoretical density 〉97% were produced using conventional P/M. The microstructure, and mechanical and wear properties of the composites were evaluated. The microstructure of the composites consisted of （core-rim structure） spherical and semi-spherical TiC particles depending on the wettability of the matrix with TiC particles. In TiC-maraging stainless steel composites, 465 stainless steel binder phase showed good wettability with TiC particles. Some microcracks appeared in the composites, indicating the presence of tensile stresses in the composites produced during sintering. The typical properties, hardness, and bend strength were reported for the composites. After heat treatment and aging, an increase in hardness was observed. The increase in hardness was at- tributed to the aging reaction in maraging stainless steel. The specific wear behavior of the composites strongly depends on the content of TiC particles and their interparticle spacing, and on the heat treatment of the maraging stainless steel.     

热处理对440A钢组织与耐磨性能的影响

通过金相显微镜、万能试验机、摩擦磨损试验机等设备进行组织分析、力学性能和耐磨性能测试,研究了在不同热处理工艺下对用于磨片的440A高碳高铬钢组织与耐磨性的影响。结果显示,该材料的最佳热处理工艺参数为：1080 ℃×40 min,油淬,300 ℃×2 h,空冷,回火两次。该工艺下材料可获得优异的综合力学性能,具有良好的耐磨性。     

锻造及热处理工艺对耐磨钢组织及耐磨性能的影响

研究了锻造变形量与热处理工艺对一种新型耐磨钢显微组织、硬度和耐磨性的影响,并用彩色金相法定量分析了钢中马氏体+残留奥氏体含量。结果表明:不同变形量下耐磨钢组织均为贝马复合相,贝氏体板条厚度由30%变形量的524 nm降低到70%变形量的292 nm,马氏体+残留奥氏体体积分数由25.4%增加至41.1%;与直接进行260 ℃等温转变时相比,先在Ms点以上的330 ℃保温5 min,再进行260 ℃等温转变时的贝氏体板条厚度减少了357.2 nm,磨损量降低了0.02 g,且平均摩擦因数由0.311降至0.212。     

65MnCr耐磨钢的连续冷却转变和组织性能

设计了一种新型65MnCr耐磨钢,并对其CCT曲线进行测定,研究该钢不同冷速下的组织变化及热处理后的组织性能.结果表明,65MnCr钢的临界冷却速度在1～3℃/s之间,Ms点184℃,具有很高的淬透性,完全淬透后,马氏体硬度达64 HRC,淬硬性好.φ130 wn柱状试样经水淬+自回火后,冲击吸收能量在15 J以上,从表面至心部,硬度分布均匀,均在48 HRC以上,组织依次为回火马氏体、马氏体+块状(马氏体+奥氏体)组织、马氏体+粒状贝氏体+块状(马氏体+奥氏体)组织,是一种理想的可供大尺寸构件用耐磨材料.     

Abrasive slurry wear behavior of stainless steel surface produced by plasma transferred arc hardfacing process

Abrasive slurry wear is generally defined as a mechanical interaction in which material is lost from a surface which is in contact with a moving particle-laden liquid. Slurry wear abrasion occurs in extruders, slurry pumps, and pipes carrying slurry of minerals and ores in mineral processing industries. The life of components used under slurry abrasion conditions is governed by the process parameters, properties of the abrasive particles in the slurry and the material properties. This paper analyzes in detail the effects of operating variables such as abrasive particle size, slurry concentration, speed of rotation and slurry bath temperature on the abrasive slurry wear behavior of a stainless steel surface produced by Plasma transferred arc (PTA) hardfacing process. Of the four variables considered in this investigation, it is found that the slurry concentration has a predominant effect on wear rate of hardfaced surfaces compared to other variables. Microstructural analyses of the worn surfaces were carried out using SEM. Both experimental and mathematical investigations show that the wear resistance of the PTA hardfaced stainless steel surface is four times better than that of the carbon steel substrate.     

三种热处理工艺对低合金耐磨钢组织和磨损性能的影响

采用扫描电镜、透射电镜等研究了低合金耐磨钢经低温回火、循环热处理、一步配分热处理后的显微组织,采用磨粒磨损试验机测试其磨损质量.结果表明:试验钢经低温回火后的组织为板条马氏体加少量析出相;循环热处理的试验钢的马氏体板条消失,在原奥氏体晶界上和基体处均有碳化物析出相;淬火配分热处理的试验钢中的马氏体板条比较明显,并有少量的残留奥氏体.能谱成分分析可知,不同热处理工艺后试验钢中的微米尺寸的析出相主要是(Ti,Nb)C,球形与椭球形纳米尺寸析出相是(Ti,Nb,V,Mo)C.淬火加200℃低温回火处理的试验钢的硬度为46.5 HRC,循环热处理的试验钢的硬度最低,为31.48 HRC,淬火加一步配分热处理的试验钢的硬度为44.84 HRC.磨粒磨损实验结果表明,淬火加200℃低温回火处理后的试验钢的耐磨损性最佳,淬火加配分处理的试验钢的磨粒磨损性能与淬火加低温回火的试验钢相差不大,循环热处理的试验钢的磨粒磨损性能较差.     

热处理对中碳低合金耐磨钢组织与耐磨性的影响

研究了水冷、风冷、空冷3种冷却方式和200、250、300、350、400℃5种回火温度对中碳低合金耐磨钢的组织和耐磨粒磨损性能的影响。结果表明,经不同的冷却方式,可依次得到单相马氏体和马氏体加贝氏体的复相组织。含有贝氏体的复相组织在低温回火后有较好的抗回火软化能力和韧性,有助于耐磨性的提高。用SEM观察磨损表面,结果表明：在磨粒磨损情况下,实验用钢的磨损机理主要为塑性变形犁机制和显微切削机制。     

碳含量对Si-Mn-B铸钢显微组织和抗磨性的影响

研究了含1.5%Si-2.5%Mn-0.006%B和少量稀土、镍、铬、钛等合金的Si-Mn-B铸钢经900℃正火的显微组织和在销盘磨损和湿砂橡胶轮磨损条件下的抗磨损性能.钢中碳含量分别为0.17%、0.25%、0.34%、0.47%和0.53%.结果表明,碳含量较低时,主要形成粒状贝氏体,随着碳含量增加,钢的正火组织向针状贝氏体、上贝氏体和下贝氏体过渡,且组织变细.钢的硬度随碳含量增加而增大,冲击韧度随碳含量增加而下降.Si-Mn-B铸钢的耐磨性随碳含量的变化比较复杂.在销盘磨损条件下,使用低硬度玻璃砂磨料时,随着碳含量提高,磨损量减少,耐磨性增加,另外,材料的磨损量随着载荷的增加而增加,使用高硬度碳化硅磨料时,碳含量对磨损量的影响不明显.在湿砂橡胶轮磨损条件下,也呈现碳含量增加,磨损量减少的现象.     

Abrasive wear resistance of plasma-sprayed glass-composite coatings

A ball-milled mixture of glass and alumina powders has been plasma sprayed to produce alumina-glass composite coatings. The coatings have the unique advantage of a melted, ceramic secondary phase parallel to the surface in an aligned plateletlike-composite structure. The alumina raises the hardness from 300 HV for pure glass coatings to 900 HV for a 60 wt.% alumina-glass composite coating. The scratch resistance increases by a factor of 3, and the wear resistance increases by a factor of 5. The glass wears by the formation and intersection of cracks, while the alumina wears by fine abrasion and supports most of the sliding load. The wear resistance reaches a maximum at 40 to 50 vol.% alumina, above which there is little further improvement. This critical alumina content corresponds to the changeover from a glass to a ceramic matrix.     

Fe-Cr-C耐磨堆焊合金磨粒磨损行为

采用埋弧堆焊方法,在Q235钢表面制备Fe-Cr-C耐磨合金,在MLS—225型湿式橡胶轮磨粒磨损试验机上进行磨粒磨损试验,通过对磨损试样表面的扫描电子显微镜观察分析并结合能谱成分分析研究磨损形成机制.结果表明,Fe-Cr-C耐磨堆焊合金在试验的湿石英砂磨料磨损条件下,磨损机制以微裂纹引起的剥落去除机制为主,也存在一定数量的犁沟或犁皱造成的微切削去除机制.剥落的发生与碳化物密切相关,能谱成分分析表明剥落坑内Cr元素含量对应在(Cr,Fe)7C3铬含量范围内,说明剥落坑是碳化物断裂造成的.     

Hardness,wear and microstructure of carbon implanted AISI M2 high speed steel

The hardness, wear behaviour and microstructure of AISI M2 high speed steel implanted with carbon ions are discussed. The samples were implanted at an energy of 100 keV. The doses ranged from 1×10¹⁷ C⁺/cm² to 3×10¹⁸ C⁺/cm². Hardness increases due to ion implantation, but no significant dose dependence is found. For lower doses the wear effects mainly the pin, but from doses of 5×10¹⁷ C⁺/cm² onwards a pronounced ploughing of the disk is observed. The abrasive wear rate decreases with increasing dose. Microstructural investigations reveal the presence of ε-carbide and graphitic carbon in the implanted volume. A possible correlation between hardness and wear is discussed based on the microstructural results.     

回火温度对M50钢组织及摩擦磨损性能影响

采用X射线衍射仪、扫描电镜、洛氏硬度计、摩擦磨损试验机等研究了不同温度(160、300和540℃)回火处理对淬火态M50钢的微观组织、硬度及摩擦磨损性能的影响.结果 表明:经1090℃淬火后M50钢显微组织由马氏体、碳化物及残留奥氏体组成,硬度为64.5 HRC,残留奥氏体含量为18％;回火处理使M50钢组织中马氏体转变为回火马氏体,随着回火温度的升高,试验钢硬度先降低再升高,其中,300℃回火时试验钢的硬度较低,540℃回火出现二次硬化现象,硬度值较大,残留奥氏体含量较低约4％.摩擦磨损试验结果表明:540℃回火处理可以有效降低试验钢的摩擦系数和磨损率,其磨损机制为轻微磨粒磨损伴随粘着磨损.     

淬火温度对Cr5支承辊用钢组织和摩擦磨损性能影响

运用扫描电子显微镜和洛氏硬度计研究了Cr5支承辊用钢不同热处理状态下的显微组织和洛氏硬度。结果表明,调质处理后Cr5钢组织得到明显改善(回火索氏体),细小弥散分布的碳化物取代尺寸较大不规则的碳化物;淬火后试样组织为马氏体,碳化物几乎全部溶入基体,硬度随淬火温度提高而增加(由51.6 HRC增加到58.1 HRC);回火后,Cr5钢中有细小碳化物析出,且弥散分布,淬火温度较高(1050℃、1025℃)时,组织依然保留马氏体结构(回火马氏体),温度较低(1000℃)时,组织为回火索氏体,其硬度与回火前变化趋势相同(由51.4 HRC增加到54.4 HRC)。在所选定的淬火温度下,随着淬火温度的升高,硬度值增大,磨损量减小,磨损严重程度降低,耐磨性较好。     

Si、Mn含量比对贝氏体铸钢组织和耐磨性的影响

研究了Si/Mn含量比对贝氏体铸钢组织和耐磨性的影响。结果表明,Si/Mn含量比较低时,组织主要为马氏体,随Si/Mn含量比升高,马氏体量降低,下贝氏体量提高;耐磨性提高。     

回火温度对颗粒增强型低合金耐磨钢组织和性能的影响

研究了不同回火温度下颗粒强化型低合金耐磨钢的微观组织、力学性能和耐磨性能,确定了最佳的回火工艺。结果表明,轧制态颗粒强化型低合金耐磨钢中均匀弥散分布着大量微米级和纳米级TiC析出。回火温度升高,基体中ε-碳化物增多,试验钢的屈服强度整体上先升高后降低,抗拉强度、硬度和冲击吸收能量逐渐降低,伸长率逐渐升高,在200 ℃低温回火时,试验钢表现出最优的综合力学性能,同时表现出最佳的三体磨料磨损性能。     

热处理对钼铜奥氏体不锈钢组织和耐腐蚀磨损性能的影响

研究了热处理工艺(不同固溶温度和固溶时间)对钼铜奥氏体不锈钢析出物含量和形态的影响,以及在不同固溶温度下材料的耐腐蚀磨损性能.试验结果表明,钼铜奥氏体不锈钢析出物随固溶温度的升高和固溶时间的延长而增多,其形态也由针棒网状长成块状;在纯磨损环境下,1100 ℃×8 h空冷下的奥氏体不锈钢析出物数量最多,耐磨损性能最好;而在有酸的腐蚀磨损环境介质中,950 ℃×8 h空冷的热处理工艺下的材料耐腐蚀磨损性能最佳.