Study Of Influences On The Property Of WC-Co/Steel Brazed Joints

In order to meet the urgent requirement of high wear-resistant cemented carbides covered tamping tine, brazing of cemented carbide to alloy steel was carried out by using normal BAg-24 fill metal and compound BAg-24 sandwich foils with copper intermediate layer. Effects of braze processing of two filler metal was studied by the spreading experiment and shear test. Residual stress distribution of the tamping plate brazed with two different filler metals and stress distribution of the whole tamping tine during tamping was carried out by using FEM software ABAQUS.The tamping operation was done to validate and the numerical result is practical.The spreadability of cemented carbide and alloy steel surfaces by using BAg-24 filler metal were discussed experimentally. Spreading area increased on the rough steel surfaces with blasting and BAg-24 alloy could spread well on the cemented carbide surface by using FB3-B flux.The interfacial reaction of WC-Co/steel by using BAg-24 filler metal and sandwich alloy with Cu ductile layer was discussed. The results showed that microstructure of the BAg-24 joint changed obviously after heat treatment. Cu(s. s) grainy located in the whole joint evenly and the Zn content increased. Compared with 757℃ brazed joint, element diffusion of the sandwich alloy between copper intermediate layer and BAg-24 alloy increased when joint brazed at 807℃.A long elastic deformation stage was found in the force-displacement curve of BAg-24 joint with heat treatment during the shear test. Joint brazed with sandwich alloy turns out better shear capacity with 807℃ brazing temperature than 757℃ brazing temperature. Shear capacity of WC-Co/steel brazed joints can be better reflected by using shear deformation energy.The residual stress distribution of three different compound tamping plates which were widely used was investigated by numerical simulation. It shows that each tamping plate structure has issues with stress concentration and tensile stress on WC-Co surface which can cause fracture while working. The peak stress of WC-Co brazing surface can be reduced brazing by compound sandwich alloy and the tensile stress on the WC-Co friction surface decreased obviously at the same time. The result proved that compound sandwich alloy with Cu intermediate layer can reduce the influence to the wear-resistance of WC-Co cause by postweld residual stress.Numerical stimulation of three tamping tines with the same loading condition according to the tamping operation was carried out by using commercial ABAQUS/dynamic procedure. The danger sections were found and the tamping operation was done to validate and the result is practical.