合金元素对SHS伴生金属涂层基本性能的影响

 为探究合金元素对伴生金属涂层基本性能的影响，选用Ф78 mm×8 mm×550 mm的无缝钢管，在管内壁距离管端200~350 mm处提前开设150 mm×10 mm×4 mm的长形槽，采用自蔓延高温合成技术制备添加不同含量合金元素的伴生金属涂层。通过维氏硬度测量、电子显微扫描、酸液浸泡腐蚀试验，分别探究不同合金元素对伴生金属涂层孔隙、裂纹、硬度以及耐蚀性能的影响。结果显示，添加 Nb、Cr 元素后伴生金属层硬度提高，孔隙与裂纹明显减少，金相组织趋于均匀化。伴生金属层的耐蚀性能与Cr、Nb元素添加量成正比，ZrO₂的添加量影响不大。耐蚀性最好的伴生金属涂层腐蚀仅失重0.271 g，失重率为2.71%，失重率仅为纯铁层的21.22%。结果表明，Nb、Cr元素的加入能有效改善伴生金属涂层的基本性能，而Zr元素对涂层性能影响较小。

Effect of alloying elements on basic properties of SHS associated metal coatings

The effect of alloying elements on the basic properties of associated metal coatings is investigated. A seamless steel pipe with diameter of Ф78 mm*8 mm*550 mm is selected, and a long groove of 150 mm*10 mm*4 mm is set in advance at 200~350 mm from the inner wall of the pipe to the end of the pipe, and the associated metal coatings with different contents of alloying elements are prepared by self propagating high temperature synthesis technology. The effects of different alloy elements on pores, cracks, hardness and corrosion resistance of associated metal coatings are then investigated by Vickers hardness measurement, electron microscopic scanning and acid immersion corrosion test. After adding Nb and Cr elements, the hardness of the associated metal layer increases, pores and cracks are obviously reduced, and microstructure tends to be homogenized. The corrosion resistance of the associated metal layer is directly proportional to the amounts of Cr and Nb, but the amount of ZrO₂ has minor effect. The weight loss of associated metal coating with the best corrosion resistance is only 0.271 g, the weight loss rate is 2.71%, and the weight loss rate is only 21.22% of the pure iron layer. Addition of Nb and Cr can effectively improve the basic properties of the associated metal coating, while Zr has minor effect on the properties of the coating.