1 Products Description
Driven by explosive impact ‚ The connection of two metal plates after high-speed collision is called explosive welding. Explosive welding can weld two metals that are difficult or cannot be connected by fusion welding ‚ In addition, the process is simple ‚ Strong connection ‚ Large composite area ‚ High production efficiency ‚ Low cost ‚ And the thickness and thickness ratio of the covering layer and the base layer can be adjusted at will ‚ Therefore, High strength c11000 copper clad steel sheet has become the main process method for producing composite plates at home and abroad. During explosive welding, the joint surface instantaneously absorbs the strong plastic deformation work produced by explosive collision, which makes its structure particularly complex ‚ And has a direct impact on the performance of high strength c11000 copper clad steel sheet ‚ But this junction area is very thin ‚ It is difficult to distinguish its details under optical microscope ‚ In this paper, SEM and TEM are used to analyze the microstructure of the bonding interface ‚ This is important for understanding the process and mechanism of explosive welding and guiding the formulation of explosive welding process ‚ It also has important reference value in reducing the scrap rate of products and improving the quality and service life of products.
2 Test results of hardness distribution in bonding zone
See Figure 1 for the hardness distribution in the bonding zone of T2/20 # explosive welded composite plate. It can be seen from Figure 1 ‚ The hardness of bonding zone is higher than that of clad plate and base plate ‚ Especially, the hardness at the interface is the highest. This shows that the composition and structure of the bonding zone have changed after explosive welding compared with the cladding and substrate.
3SEM results
After polishing, the naked eye can see that the bonding interface is serrated. After etching, the wavy structure is clearly displayed under the scanning electron microscope (see Fig. 2a) ‚ Wave height 0.3mm ‚ Wavelength 1.0mm. The single peak a can be further seen by high magnification ‚ There are two vortex areas at the front (right) and the back (left) of the wave on both sides of the wave ‚ They are the front vortex (Fig. 2b) and the rear vortex (Fig. 2c). There are pores and porosity of different sizes in the front vortex ‚ There are trapped pieces of metal in the rear vortex (see Fig. 2d). The grain on the steel side near the bonding interface presents rheological phenomenon ‚ That is, the grain is elongated along the wave propagation direction ‚ And with the wave bending. This rheological phenomenon is more serious as it is closer to the bonding interface. See Table 1 for the composition analysis results of Zone A (front vortex), Zone B (on the interface) and Zone C (rear vortex) in Figure 2.
4 Results of transmission electron microscopy
Under transmission electron microscope ‚ The interface steel side is strip deformed structure ‚ There are high-density dislocations in the strip (Fig. 3a) ‚ Selected area electron diffraction shows that the strip structure is α－ Fe (Fig. 3b). The grains on the copper side of the interface are elongated ‚ There are high-density dislocations in the crystal (Fig. 4a) ‚ Twin structure is also visible (Fig. 4b). in addition ‚ Microcrystalline layer was observed on the copper side (Fig. 5) ‚ Its structure is to be determined.
Issiq teglar: high strength c11000 copper clad steel sheet, China, manufacturers, suppliers, factory, customized, buy, price, quality, quotation, pricelist, in stock
