316不锈钢表面等离子渗B、Mo-B共渗及其摩擦磨损性能的研究

发布时间：2017-12-31 05:15

本文关键词：316不锈钢表面等离子渗B、Mo-B共渗及其摩擦磨损性能的研究　出处：《太原理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：AISI316奥氏体不锈钢作为重要的工程材料具有良好的综合性能。例如，优美的外观、优异的耐腐蚀性能、良好的塑性和韧性等，因此在海洋、化工、食品、航空、化工、医疗、汽车等领域具有广泛的应用和发展前景。然而AISI316奥氏体不锈钢存在硬度比较低、耐磨性比较差的缺陷，特别是极易产生粘着磨损，从而阻碍了奥氏体不锈钢的应用。表面合金化技术成为解决这一问题的首选方法。双辉等离子表面合金化技术凭借简单、渗入效率高、膜基结合强度高的优点，，成为表面改性的热点。前期实验研究结果表明，通过在奥氏体不锈钢表面形成硬质改性层可以提高其摩擦学性能。在不锈钢表面改性方法中，渗硼层凭借其较高的硬度，较高的耐磨性，尤其是良好的耐粘着磨损和磨粒磨损性能受到研究人员的广泛关注。本文通过采用双层辉光等离子表面合金化技术对316奥氏体不锈钢进行渗B和Mo-B共渗处理，制备表面含硼、钼硼改性层，分别对渗层的组织结构、成分分布、相结构和显微硬度等进行分析，并重点探讨研究干摩擦条件下不同载荷和配副对渗硼及钼硼改性层摩擦磨损性能的影响及磨损机理。得出如下结论： (1)316奥氏体不锈钢在不同工艺下双辉等离子表面渗B及Mo-B共渗处理后，在试样表面均能获得一定厚度、组织均匀的改性层。改性层的厚度分别约为8μm和23μm；两种改性层中B元素的含量在表面最高，由表及里在一定深度范围内呈梯度下降趋势；经渗B处理后改性层主要由FeB、Fe2B及Ni3B、CrB和γ组成，而Mo-B共渗处理后同时还形成了FeMo2B2和Mo2B相；渗B及Mo-B共渗两种改性层的表面硬度分别是基材的4倍和4.5倍。划痕测试表明，两种改性层与基材具有良好的结合性能。 (2)在干摩擦条件下，以GCr15钢球为摩擦配副，在1N、2N、5N三种载荷下，两种改性层的摩擦系数均小于基体，比磨损率也远小于基体，其减摩性和耐磨性能在一定程度上得到提高。载荷为1N、2N时，渗B处理试样的耐磨作用更为显著明显。5N载荷下，Mo-B共渗处理后试样耐磨性更好。 (3)以Al2O3陶瓷球为摩擦配副，经Mo-B共渗处理试样的平均摩擦系数均大于未处理的不锈钢基体，Mo-B共渗改性处理对基材没有减摩作用。但2N、5N载荷下的摩擦学性能均得到改善。10N载荷下，膜层被磨穿，耐磨性较差。 (4)316奥氏体不锈钢基体与GCr15及Al2O3对磨时的主要磨损机制是粘着磨损和磨粒磨损，而经渗硼、Mo-B共渗处理后试样主要是微磨粒磨损为主，含有少量的粘着磨损。
[Abstract]:AISI316 austenitic stainless steel as an important engineering material with good comprehensive properties. For example, beautiful appearance, excellent corrosion resistance, good plasticity and toughness, therefore in marine, chemical, food, aerospace, chemical, medical, and has wide application and development prospect of automotive and other fields. However, existing AISI316 austenitic stainless steel low hardness, wear resistance of the defects are relatively poor, especially prone to adhesive wear, which hinders the application of austenitic stainless steel. The surface alloying technology has become the preferred method to solve this problem. The double glow plasma surface alloying technology with simple, into high efficiency, combined with the advantages of high strength of the film substrate, a surface the modified hot spots.
The experimental results show that the formation of hard modified layer can improve the tribological properties of austenitic stainless steel in the stainless steel surface. The surface modification methods, boronizing layer because of its high hardness, high wear resistance, especially resistance to adhesive wear and abrasive wear properties have attracted much attention by good. Of the 316 austenitic stainless steel B and Mo-B infiltration seepage treatment by double glow plasma surface alloying technique, surface preparation of boron, molybdenum and boron modified layer, the distribution structure of the boride layer respectively, component analysis, phase structure and microhardness, and focuses on the study of dry friction under different load and a pair of molybdenum and boron modified on Boronizing layer friction and wear properties and wear mechanism. The main conclusions are as follows:
(1) 316 austenitic stainless steel under different process of double glow plasma surface infiltration of B and Mo-B infiltration treatment, at the surface of the sample can obtain a certain thickness, uniform microstructure of modified layer. The thickness of the modified layer were approximately 8 m and 23 m; the content of two kinds of modified B element layer on the surface of the high gradient, from the outside to the inside to decline in a certain depth range; the B surface modified layer is mainly composed of FeB, Fe2B and Ni3B, CrB and Mo-B gamma, seepage treatment and formation of FeMo2B2 and Mo2B; B and Mo-B infiltration permeability of two kinds of modified layer the surface hardness of the substrate is respectively 4 times and 4.5 times. Scratch test showed that two kinds of modified layer and the substrate with good performance.
(2) under the condition of dry friction, with GCr15 steel as friction pair, in 1N, 2N, 5N three kinds of loads, two kinds of friction coefficient of the modified layer are smaller than those of the matrix, the specific wear rate is far less than the substrate, the friction and wear properties were improved to a certain extent. Load 1N, 2N, B surface wear-resistant specimen is more significant.5N loads, Mo-B infiltration treated better wear resistance.
(3) to Al2O3 ceramic ball friction pair, the average friction coefficient of Mo-B carbonitriding samples were higher than the untreated stainless steel substrate, Mo-B alloying modification without friction reducing effect on the tribological properties of 2N substrate. But, under the loading of 5N were improved under.10N loading, the film was worn out. Poor wear resistance.
(4) the main wear mechanism of 316 austenitic stainless steel matrix and GCr15 and Al2O3 is abrasive wear and abrasive wear. However, after boronizing and Mo-B CO treatment, the main abrasive wear is mainly abrasive wear and a small amount of adhesive wear.

【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG174.4

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