双金属液-固复合工艺对界面层影响的研究

Study on the Technology of Bimetal Liquid-Solid Composite Wear Layer

本文主要从铸件浇注位置、钢液浇注厚度两个方面,探讨了在铸造过程中工艺因素对复合界面层结合程度和不同区域组织性能的影响。实验结果表明:铸件浇注位置由竖直改为水平,能有效防止部分铸铁层被高温钢水熔透;浇注钢液厚度35 mm时,复合界面的结合区组织致密,达到冶金结合状态,无夹渣等缺陷;铸钢侧组织为珠光体+铁素体,高铬铸铁侧组织为铬奥氏体加少量M7C3碳化物。硬度测试表明:结合区显微硬度介于两金属硬度值之间,硬度的梯度变化有利于改善使用过程中受力状态,避免结合部位发生断裂。

In this paper,the effects of process factors on the degree of composite interface bonding and microstructure of different regions during the casting process are discussed from the aspects of casting casting position and molten steel casting thickness. The experimental results show that the cast position of the casting is changed from vertical to horizontal,which can effectively prevent some cast iron layers from being penetrated by high temperature steel. When the thickness of molten steel is 35 mm,the joint area of the composite interface is dense,metallurgical bonding state,no slag inclusion,etc. Defects;the side of the cast steel is pearlite +ferrite,and the side of the high chromium cast iron is chromium austenite + a little M7 C3 carbide. The hardness test shows that the microhardness of the bonding zone is between the hardness values of the two metals,and the gradient of the hardness is beneficial to improve the stress state during use and avoid the fracture of the bonding site.