The ferrous industry keeps evolving, and the demand for castings with complex geometries is increasing. Due to this, some foundries are facing several challenges when it comes to producing highly complex parts with a specific microstructure. Normally, heat treatment is performed when a ferritic matrix is desired. However, distortion and cracking can become a problem too. Because of this, it is important to explore alternative methods that can potentially help with these problems. In ductile iron, cobalt additions are known to increase the nodule count, which favors higher ferrite fractions. Hence, the addition of cobalt was studied to investigate its effects on the microstructure and tensile properties of ductile iron. Five heats were produced and cast into ½ inch ASTM A536 Y-blocks: 0 wt%, 1 wt%, 2 wt%, 3 wt%, and 4 wt% Co. Metallography was performed to evaluate the percent nodularity, nodule count (N/mm²), and ferrite/pearlite percentages. Tensile testing was executed using sub-size round samples. Brinell hardness and micro-Vickers were conducted on each Y-block to assess the macro and microscopic behavior of the cobalt bearing ductile iron. The addition of 4 wt% Co was found to decrease the nodule size and increase the percent nodularity and nodule count resulting in higher ferrite contents. Cobalt did not have a statistically significant effect in tensile strength and percent elongation. However, cobalt was found to increase the yield strength due to the solid solution strengthening effect in ferrite.

黑色金属行业不断发展，对复杂几何形状的铸件的需求也在增长。因此，一些铸造厂在生产具有特定微观结构的高度复杂的零件时面临着若干挑战。通常，当需要铁素体基体时进行热处理。但是，变形和破裂也可能成为问题。因此，重要的是探索可能有助于解决这些问题的替代方法。在球墨铸铁中，已知添加钴会增加根瘤数，这有利于更高的铁素体含量。因此，研究了钴的添加以研究其对球墨铸铁的组织和拉伸性能的影响。产生五次加热并浇铸到½英寸ASTM A536 Y块中：0 wt％，1 wt％，2 wt％，3 wt％和4 wt％Co。²），以及铁素体/珠光体的百分比。使用小尺寸的圆形样品进行拉伸测试。在每个Y型块上进行布氏硬度和显微维氏分析，以评估含钴球墨铸铁的宏观和微观行为。发现添加4wt％的Co减小了结节尺寸并增加了结节百分数和结节数，导致较高的铁素体含量。钴对拉伸强度和伸长百分率没有统计学上的显着影响。但是，发现钴由于铁素体中的固溶强化作用而提高了屈服强度。