电弧喷涂用巴氏合金丝研究

论文总字数：31272字

摘 要

轴瓦与轴构成摩擦副，支撑传动轴转动，是机械设备中重要的零部件。在钢铁基体上浇注巴氏合金是目前经常使用的轴瓦制造方法，但仍然存在巴氏合金与基地材料的结合力低，生产效率偏低等问题。近年来，采用焊接熔覆巴氏合金的方法在轴瓦制造中逐步得到应用，特别对于重载大型轴承，其高效、高质量的特点尤其突出。为进一步提高效率，可采用MIG焊（熔化极钨极氩弧焊）替代TIG焊（非熔化极钨极氩弧焊），但在焊接的过程中，需要满足高速送丝要求，且焊丝直径需进一步降低至1.6mm以下，这对具有脆硬特性的Sn基巴氏合金（特别是ChSnSb11-6）的加工提出了新的要求。

基于上述原因，本论文选择组织细化的方法改善材料的加工性能，以期解决巴氏合金在拉丝过程中容易断裂的问题。此外，探索通过改变组织提高焊丝材料的屈服强度的方法，这对于焊丝在焊接过程中控制电弧具有重要意义。本文将采用含Sb量较高的锡基巴氏合金ChSnSb11-6作为研究对象，通过非均匀形核原理，采用颗粒尺寸分别为2-3um的TiC和5-8um的TiB2两种粉末以及中间合金细化剂X对铸态组织进行细化，并对铸态、挤压 拉拔态的合金以及焊缝进行组织和性能的对比研究。

铸态下的金相组织显示：随着细化剂的加入，相组织尺寸呈下降的趋势，且合金延伸率在一定成分范围内提高。结合其力学性能（包括硬度，延伸率以及强度等性能），优选TiC粉末在添加量为质量分数0.60%，TiB2粉末在添加量为0.40%，中间合金细化剂X的添加量为0.75%的合金进行挤压和拉拔。拉拔后，对丝材进行组织观察和性能测试，可以发现拉拔后合金组织产生了细化，屈服强度和硬度都有提高，满足焊接时高速送丝和电弧控制的要求。

关键词：巴氏合金、细化、硬度和延伸率、焊接

Abstract:

Bearing and shaft friction pair, supporting shaft turn, is an important parts in machinery and equipment. Casting babbitt on steel substrate is now commonly used bearing manufacturing method, but there is still a low the adhesion strength of the base material and babbitt, the production efficiency is low. In recent years, with the method of weld cladding babbitt has been applied in the manufacture of bearing shell gradually, especially for overloaded large bearings, the characteristics of its high efficiency, high quality. In order to further improve the efficiency, can use MIG welding (melting polar tungsten argon arc welding) alternative TIG welding (not melt tungsten argon arc welding), but in the process of welding, need to meet the requirements of high speed wire feed, and to be further reduced to less than 1.6 mm wire diameter, the brittle characteristics of Sn base babbitt (especially ChSnSb11-6) processing and put forward the new requirements.
Based on the above reasons, this thesis choose organization refinement methods improve the processing performance of materials, in order to solve the babbitt easily fracture problems in the process of drawing.In addition, the exploration by changing the organization improve the wire material yield strength, the method of this for the wire in the arc during the welding process control is of great significance.Containing a high percentage of Sb is adopted in this paper tin base babbitt ChSnSb11-6 as the research object, through the principle of heterogeneous nucleation, the particle size of 2-3 um TiC respectively and 5-8 um TiB2 among two kinds of powder and alloy refining agent X for thinning as-cast organization, and the as-cast, alloy extrusion drawing mode, and comparative study of the organization and performance of weld.

As-cast microstructure show that with the addition of refiner, organization size a downward trend, and alloy elongation within the scope of certain components increase. Combined with its mechanical properties (including hardness, elongation and strength etc.), optimizing TiC powder adding quantity for mass fraction 0.60%, TiB2 powder adding quantity 0.40%, the adding amount of intermediate alloy refining agent X for 0.75% of the alloy extrusion and drawing. After drawing, microstructure observation and performance test was carried out on the wire, can be found after drawing produced the refined microstructure, yield strength and hardness are increased, meet the requirements of high speed wire and electric arc welding to control. Bearing and shaft friction pair, supporting shaft turn, is an important parts in machinery and equipment. Casting babbitt on steel substrate is now commonly used bearing manufacturing method, but there is still a low babbitt and the adhesion strength of the base material, the production efficiency is low. In recent years, with the method of weld cladding babbitt has been applied in the manufacture of bearing shell gradually, especially for overloaded large bearings, the characteristics of its high efficiency, high quality. In order to further improve the efficiency, can use MIG welding (melting polar tungsten argon arc welding) alternative TIG welding (not melt tungsten argon arc welding), but in the process of welding, need to meet the requirements of high speed wire feed, and to be further reduced to less than 1.6 mm wire diameter, the brittle characteristics of Sn base babbitt (especially ChSnSb11-6) processing and put forward the new requirements.

Based on the above reasons, this thesis choose organization refinement methods improve the processing performance of materials, in order to solve the babbitt easily fracture problems in the process of drawing.In addition, the exploration by changing the organization improve the wire material yield strength, the method of this for the wire in the arc during the welding process control is of great significance.Containing a high percentage of Sb is adopted in this paper tin base babbitt ChSnSb11-6 as the research object, through the principle of heterogeneous nucleation, the particle size of 2-3 um TiC respectively and 5-8 um TiB2 among two kinds of powder and alloy refining agent X for thinning as-cast organization, and the as-cast, alloy extrusion drawing mode, and comparative study of the organization and performance of weld.

As-cast microstructure show that with the addition of refiner, organization size a downward trend, and alloy elongation within the scope of certain components increase. Combined with its mechanical properties (including hardness, elongation and strength etc.), optimizing TiC powder adding quantity for mass fraction 0.60%, TiB2 powder adding quantity 0.40%, the adding amount of intermediate alloy refining agent X for 0.75% of the alloy extrusion and drawing. After drawing, microstructure observation and performance test was carried out on the wire, can be found after drawing produced the refined microstructure, yield strength and hardness are increased, meet the requirements of high speed wire and electric arc welding to control.

Keywords: Babbit, refinement, hardness and elongation, welding

目录

摘要： I

Abstract: II

第一章 绪论 1

1.1引言 1

1.2巴氏合金 1

1.2.1巴氏合金的特点 2

1.2.2巴氏合金的分类 2

1.2.3巴氏合金的制备 3

1.3巴氏合金的细化 5

1.3.1金属细化的一般方法 6

1.3.2细化的化学方法 6

1.4巴氏合金的熔焊方法 7

1.4.1焊接方法 7

1.4.2MIG焊接 7

1.5巴氏合金熔焊技术研究现状和研究前景 8

1.6课题主要研究内容及意义 9

1.6.1课题研究的目的及意义 9

1.6.2课题研究内容 9

第二章 实验材料与设备 11

2.1实验材料及设备 11

2.1.1实验材料 11

2.1.2实验设备 11

2.2实验工艺 11

2.2.1实验工艺流程 11

2.2.2巴氏合金的制备 12

2.2.3巴氏合金的成分设计 13

2.2.4金相显微(OM)分析 13

2.2.5晶粒尺寸的测量与评定 14

2.2.6拉伸实验 14

2.2.7硬度试验 14

2.2.8扫描电镜(SEM)分析 15

第三章 细化剂对组织和力学性能的影响 15

3.1成分设计 15

3.2加入细化剂后的金相组织和分析 15

3.2.1 TiB2对组织的影响 16

3.2.2 TiC对组织的影响 17

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