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耐衝磨硬面焊合金之研究
Thesis

耐衝磨硬面焊合金之研究

謝鎮宇
Masters, 國立清華大學, 材料科學工程學系
2014

Abstract

硬面焊 衝磨 合金 磨耗 hardfacing impact-wear alloy wear
High chromium cast irons (HCCIs) are the typical commercial hardfacing alloys and many studies try to improve their properties. Based on the concepts of high entropy alloys, multi-element hardfacing alloys were developed. Pin-on-belt testing was used to evaluate the abrasion-resistant ability of these alloys. The most abrasion-resistant alloy was the THA alloy (Al1.3Cr18.4Fe38.7Mn4.4Ni2.2Mo0.4Nb4.4B28.0C2.2) and its abrasion-resistance was about 12 times of the traditional HCCIs. However, this abrasion testing results cannot imply to real cement industries. In order to reflect industrial application more truly, a new impact-wear test machine was designed. The sample which is stick to one punch moves vertically to crush quartz particles. The results show this impact-wear test can truly reflect wear-resistant properties in industrial application. Three alloy systems of HFe-HC series, UP series and THA series were used to study their impact-wear abilities. In HFe-HC series, the HFe-HC 3 alloy has the best anti-impact wear properties because of its highest toughness. However, the hardness of HFe-HC 3 is so low that its weight loss rate is still high. In UP series prepared by vacuum arc melting, the 266 alloy (Fe51.1Cr25.1Mn0.6Ni0.1Si1.3B0.4C21.4) was the best anti-impact- wear alloy. The composition of the 266 alloy was modified to improving its anti-impact-wear property via changing Fe and B content, adding precipitation hardening elements, or modifying matrix elements. We found two modified 266 alloys have the same anti-impact-wear properties (weight loss rate is 2.6 mg/h) as that of the 266 alloy. The hardness, toughness, and microstructure of alloys can intricately affect their impact-wear properties. In THA series, hardness and toughness can be improved by adding 0.25 at% tungsten into the THA alloy. The THA-0.25W alloy has the best anti-impact-wear properties and its weight loss rate is 2.2 mg/h.

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