论文部分内容阅读
结构钢钢锭在锻造过程中,将增加其密度,使一些显微孔隙得到焊合;将破坏原始的铸造结晶状态;并使钢锭中组织、成份、夹杂等的不均匀区逐步变为方向性分布,在拔长方向形成纤维.当锻造比达到2时,金属的密度已有显著的增加,从粗型组织上见到的铸态枝状晶也基本上得到破坏,无论在纵向或横向都获得了最高或接近最高的机械性能.锻造比继续增加时,粗型组织上金属的方向性纤维愈益明显.锻造比到5左右时,中心部份的纤维已很明显.锻造比为10时,几乎在整个断面上由表面直到中心都形成了极明显的纤维.纤维的形成看来对顺纤维方向的机械性能并没有改善或者改善得很微小.反之,却相当显著地降低了垂直于纤维方向的机械性能.根据本试验的结果认为:可以将各种轴类的最小锻造比,由一般公认的3或2.5修改为2.
Structural steel ingot in the forging process, will increase its density, so that some of the micro-pores get welded; will destroy the original state of foundry crystallization; and the ingot in the organization, composition, inclusions and other non-uniform area gradually become directional distribution , Forming fibers in the direction of elongation.When the forging ratio reaches 2, the density of the metal has been significantly increased and the as-cast dendrites seen from the coarse structure are also substantially destroyed, both in the longitudinal and transverse directions Up to or near the highest mechanical properties.Forging ratio continues to increase, the coarse directional tissue of the metal fibers more obvious.Forging than about 5, the central part of the fiber has been very obvious.Forging ratio of 10, almost On the whole cross-section, a very pronounced fiber is formed from the surface up to the center. The formation of fibers does not appear to improve or significantly improve the mechanical properties along the fiber direction. Conversely, it considerably reduces the perpendicularity to the fiber direction According to the results of this test, it is considered that the minimum forging ratio for various shaft types can be modified from generally accepted 3 or 2.5 to 2.