GR12 Titanium Clad Steel Plate For Industry

1. The mechanical property test shows that the average tensile strength of GR12-Q345R composite plate is 563.03MPa, which is higher than the theoretical tensile strength calculation value of 471.9MPa. The average shear strength of the composite plate is 266.1MPa, which is higher than 196MPa required by the test standard. When the internal and external bending angle of the composite plate specimen reaches 180 º, there is no crack or microcrack, and it has good bending performance. The hardness test shows that the hardness value at the bonding interface is the highest, up to 258.2HV. As the distance from the interface increases, the hardness value gradually decreases and tends to the hardness of the original base metal due to the weakening of the hardening effect of explosive welding.

2. The metallographic observation shows that the bonding interface of GR12-Q345R composite plate shows typical periodic wavy bonding, and a front vortex is formed at the matrix side. During explosive welding, both sides of the metal near the interface have plastic deformation in varying degrees. A small amount of adiabatic shear lines are formed on the TA10 side, and the grains near the Q345R interface are obviously refined. In addition, a small amount of black melt was formed at some wave peaks.

3. The XRD phase structure analysis of the bonding interface area of GR12-Q345R composite plate shows that there is a small amount of FeTi and Fe2Ti at the interface, which has no adverse effect on the performance of the composite plate due to its small content. The alloy element line scanning analysis of the bonding interface shows that during explosive welding, the Ti and Fe atoms at the interface produce obvious mutual diffusion, which is beneficial to improve the bonding quality of the composite plate interface.

 

4. The tensile fracture scanning analysis shows that the fracture surface of the composite plate base composite plate has a southern amount of equiaxed dimples, showing obvious ductile fracture characteristics. The scanning observation of the shear fracture shows that the waveforms at the fracture of the composite plate are evenly distributed, and no defects such as pores and impurities are found.

TEM analysis of the interface of the composite plate shows that the interface is narrow, about 200 nm, and no intermetallic compound is formed at the interface. At the Q345R side near the interface, there are nanocrystals and streamline structures, and the recovery and recrystallization phenomena occur in the streamline structure area.

The micromorphology of steel plate under three different surface treatments is shown in Figure 2. The elemental composition of different areas in different surface treatments is detected by energy dispersive analysis of electron probe, and the results are shown in Table 2.

Combined interface analysis

Electronic probe of bonding interface under three different surface treatments

(a) - steel brush polishing; (b) - pickling; (c) - Grind with water abrasive belt machine

In Figure 3a, a large number of inclusions are formed at the interface. The formation of these inclusions is mainly due to the formation of a closed zone when the metal surface after grinding by wire brush contacts with each other. In the process of heating, rolling and subsequent cooling, it is very easy to gather elements and form a large number of inclusions. According to the WDS analysis, the element of the inclusion is Ti (50 12% ～ 52. 3%) and C (46 12% ～ 47. 7%), it can be seen that the inclusion at the interface is very likely to be TiC. In Figure 3b, the content of the interface inclusion is significantly reduced, indicating that the roughness of the metal surface after pickling treatment is significantly reduced. During the heating, rolling and cooling after rolling, the closed area formed is small, and there is no obvious element segregation phenomenon. In Figure 3c, the compound layer at the interface is continuous, and no obvious inclusion is found.