十字头球铁表面与锡锑轴承合金层结合机理

Bonding mechanism of crosshead ductile iron surface and tin pewter layer

分析了天然气压缩机十字头有燕尾槽的球铁表面与厚的锡锑轴承合金层传统结合形式的结合机理。球铁表面与锡锑轴承合金层的结合分为球铁表面与挂锡层的结合和挂锡层与锡锑轴承合金层的结合两部分。前者主要为晶间结合；后者主要为晶内结合，借助燕尾槽的特殊作用，能够满足传统结合形式的要求。采用传统工艺实现光滑的球铁表面与很薄的锡锑轴承合金层的结合，则会出现易脱层等严重问题。鉴于此，提出两项工艺改革方案：1．采用刷镀或电镀锡工艺提高锡与球铁表面的结合力；2．采用氧乙炔火焰将锡锑轴承合金焊条熔化结合在锡表面，以提高两者的结合力。

The mechanism of the traditional bonding of crosshcad ductile iron surface with dovetail proove and thick tin pewtr layer is analyzed. The bonding can be divided into two parts. One is the bonding of ductile iron surface and tin plated layer, which is intergranular honding, and the other is the bonding of tin plated layer and tin pewter layer that is .intragranular bonding. While using the traditional technology to cany out the bonding of smooth ductile iron surface and thin tin pewter layer, some serious problems, such as disjointed layer, may occur. Thereby two reforming measures are put forward: 1. applying brush plating or electrotinning to improve the bonding force; 2. using acetylene torch to make tin pewter welding rod melting and bonding with the tin surface to improve the bonding force.