Effects of Rare Earths on Toughness of 31Mn2SiRE Wear-Resistance Cast Steel

The toughness of 31Mn2SiRE wear-resistance cast steel were increased by means of RE compound modification and high temperature austenitizing. The results show that the microstructures can be refined, needle and network ferrite are eliminated, the dislocation density and the quantity of dislocated martensite are increased remarkably, and the shape and distribution of inclusions are improved by the addition of RE. Therefore, the mechanical properties of the modified steel can be greatly increased, especially the toughness (αK) by 44%, yield strength (σs) by 10%, and elongation (δ5) by 42%.     

硅烷交联超高分子量聚乙烯

采用硅烷对超高分子量聚乙烯(UHMWPE)进行交联改性，系统地研究了交联UHMWPE的凝胶率、熔点、结晶度、力学性能与耐磨性。结果表明，硅烷偶联剂导致了UHMWPE的交联，使UHMWPE的凝胶率提高。当硅烷含量较低时，UHMWPE的熔点增高、结晶度增大；当硅烷含量较高时，UHMWPE的熔点、结晶度呈下降的趋势；硅烷交联导致了UHMWPE材料的模量和强度提高，磨耗率降低；当硅烷含量较高时，交联UHMWPE材料的力学性能和磨耗率均变差；当硅烷含量为0．2份～0．4份时，交联UHMWPE材料的综合性能最佳。     

耐磨焊条中铁、石墨和碳化硼的优化设计

堆焊焊条设计试验采用L9（34）式正交表设计,以石墨、碳化硼和铁粉3个因素为变量,通过工艺性能定性分析,硬度值正交回归,最优化计算,得到优化试验配方和建立堆焊层金属硬度的回归方程,从而找到药皮主要成分石墨、碳化硼、铁粉对堆焊金属硬度、耐磨性等性能的影响规律.其中,碳化硼影响最大,铁粉次之,最小是石墨.随着碳化硼、铁粉、石墨增加硬度与耐磨性提高.铁粉量增加焊缝成型好,飞溅小.而石墨增加焊缝成型不好.碳化硼增加,飞溅加大.得到的最佳堆焊焊条配方,其焊接工艺性能优良,硬度值达68～71 HRC.     

HM1堆焊焊条的研制

针对3Cr3Mo3W2V焊条的药皮组成、堆焊工艺、堆焊层组织进行了较为系统的试验研究。试验结果表明：该焊条堆焊后，经热处理基本达到3Cr3Mo3W2V热作模具的工作要求。     

W18Cr4V激光表面合金化表面形貌与耐磨性能的研究

利用0～2kw连续可调CO_2气体激光器对W_18Cr_4V表面进行不同预徐敷材料的激光表面合金化(LSA).考察了合金粉末成分、激光处理工艺参数、预徐敷层厚度对LSA后表面形貌以及耐磨性的影响规律.     

纳米复合Ti-B-N薄膜的结构和摩擦学性能

研究了射频等离了体辅助化学气相沉积（PCVD）技术获得的Ti-B-N薄膜的组织结构和力学性能。结果发现，B元素的加入使薄膜中出现TiN纳米晶和BN非晶（nc-TiN／a-BN）的复合结构，其硬度显著高于TiN薄膜，最高可达40GPa。用球盘式摩擦磨损实验考察了薄膜的磨损特性。结果表明：与TiN薄膜相比，Ti-B-N薄膜抗磨损性能有显著提高，磨损机制与TiN薄膜不同，摩擦系数较TiN稍高。     

等温淬火奥—贝球铁抗磨性能的研究

对用３００℃和３６０℃等温淬火的奥－贝球铁的机械性能和抗磨性能进行了测试，结果表明：等温淬火奥－贝球铁是一种具有良好综合力学性能和抗磨性能的抗磨材料。     

射频等离子体辅助化学气相沉积Ti-B-N薄膜的结构与性能

研究了射频等离子体辅助化学气相沉积获得的Ti-B-N薄膜的微观组织结构和力学性能.结果表明:B的加入使Ti-B-N薄膜中出现TiN纳米晶、BN非晶和TiB2非晶(nc-TiN/a-BN/a-TiB2)的复相结构.Ti-B-N薄膜组织致密,晶粒细小,薄膜硬度显著提高.用球盘式磨损实验考察了薄膜的摩擦学特性.与TiN相比,Ti-B-N薄膜抗磨损性能有显著提高,磨损机制为微观切削与疲劳磨损共同作用,但摩擦系数较TiN稍高.     

Microstructure Control of Thermally Sprayed Co-Based Self-Fluxing Alloy Coatings by Diffusion Treatment

This article describes microstructure control aimed for wear-resistance improvement of Co-based (Co-Cr-W-B-Si) self-fluxing alloy coating by diffusion treatment. The diffusion treatments of thermally sprayed Co-based self-fluxing alloy coating on steel substrate were carried out at 1370-1450 K for 600-6000 s under an Ar gas atmosphere. Microstructural variations of the coating and the interface between the substrate and the coating were investigated in detail. A proper diffusion treatment precipitates two kinds of fine compounds in Co-based matrix. X-ray diffractometer (XRD) and electron probe microanalyzer (EPMA) analysis revealed these precipitates to be a chromium boride dissolving cobalt and a tungsten boride containing cobalt and chromium. The size of each precipitate became larger with increasing treatment temperature and time. A coating with the proper size borides showed a superior wear-resistance. This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain Montavon, Ed., ASM International, Materials Park, OH, 2007.     

稀土对45钢固体硼氮共渗过程的影响

研究了稀土对４５钢固体硼氮共渗工艺、渗层成分、组织、耐磨性及断口形貌的影响。试验结果表明,稀土的加入使渗速增大,渗层中Ｂ,Ｎ含量特别是Ｎ的含量增加,硼化物针齿变得细密、直长;且ＦｅＢ的相对含量减少,Ｆｅ２Ｂ相增加,渗层耐磨性提高,同时稀土增加了过渡区厚度,减少裂纹源。生产应用证明,稀土硼氮共渗可使烟机配件的使用寿命大幅提高。