【作者】 应小东；

【导师】 李午申；

【作者基本信息】 天津大学 ， 材料加工工程， 2004， 硕士

【摘要】 本文以冶金行业冷轧工作辊堆焊修复为背景，开发一种强韧化性能较高的超高硬度抗裂堆焊材料。由于冷轧工作辊要求硬度高(大于60HRC)，抗疲劳剥落能力强，因此要求堆焊材料不仅硬度高，而且要具有优良的抗裂性及强韧性。本文在前期工作对堆焊材料合金系统进行优化的基础上，采用电磁搅拌和微合金化变质处理这两种方法来进一步提高堆敷金属的韧性。在焊接工艺方面，本文利用外加电磁搅拌产生的洛仑兹力对焊接熔池进行搅拌。电磁搅拌使堆敷金属组织细化、打碎网状碳化物，减小夹杂物粒度大小，提高堆敷金属组织的化学成分均匀性，最终改善了堆敷金属的韧性，使堆敷金属的冲击功提高27.7%。在焊接冶金方面，本文在优化基础合金系统C-Cr-Mo-W-V的基础上，分别或复合添加Ti、Nb、Ta三种变质剂，通过微合金化变质处理来促进异质形核，使基体组织得到细化，改善碳化物的形态、分布，从而达到提高堆敷金属韧性的目的。研究证明，采用电磁搅拌技术和微合金化变质处理可有效地改善堆敷金属中的组织和强韧性。更多还原

【Abstract】 Based on repairing the cold working roll in the field of metallurgy, this article is to develop a kind of material with super hardness and better toughness. Due to the strict demand for the super hardness over 60 HRC and crack resistance for the cold mill working roll ,the piled material must be provided with not only super hardness but also crack resistance and better toughness .Based on the formerly research about the optimization for the piled material ,this article will discuss how to increase the toughness of the piled metal on the condition of having super hardness through electromagnetism stirring and .modification.On the welding technology aspect, in order to increase the toughness , the article discuses the effect of the Lorentz force which will stir the weld molten pool. This kind of electromagnetism-stirring can refine the crystal grain and make the carbide net broken, decrease the size of the trapped oxide and improve the homogeneous of the chemical component; so that the toughness will be increased, the toughness has been increased 27.7%. On the weld metallurgy aspect, after the optimization of the basic alloy system including C, Cr, Mo, W, V, some modificators such as Ti，Nb，Ta are added into the welding wire. Through modification the size of the grain will decrease ;the shape and distribution of the carbide will be changed; so that the toughness can be improved .更多还原