用高速钢W18Cr4V扁锭锻造方坯时内部裂纹的研究

在微机上采用刚-粘塑性有限元分析法对高速钢锻造过程进行了模拟研究,发现纵向裂纹主要是由于锻造过程中双鼓形的存在,使锻平时横截面内出现较大横向拉应力,其数值超过坯料强度而形成的。据此提出了合理工艺参数和改进锻造工艺的措施,有限元分析结果与实际相符。

A Research on Internal Crack in Square Billet Forged from the Flat Ingot of Highspeed Steel W18Cr4V

Forged from the flat ingot of the high-speed steel, W18Cr4V, the square billet was tested by ultrasonic. In the hurled-wave,sliced sheet,where a. kind of longitudinal small cracks whose form and distribution had some definite rule could be found. Different to the forging cracks introduced in the traditional high-speed steels technology,the cracks were difficult to be explained by that theory. With the forging process of the high-speed steels having been simulated and researched by the rigid-viscoplastic FEM in the microcomputer,the reason why cracking may occur at the center area of the billet is the existence of the double dulging in the; forging process. When it was forged to plat,high cross tensile stress in the billet developed and exceeded the strength of the billet. Accordingly, the reasonable parameters and the steps made the forging technology better were put forward, and the results analyzed by FEM were agreeable to practical results.