Hydrogenation after rolling A387 Gr 11 CL2 steel plate after normalizing heat treatment after mechanical properties are shown in the table below. It can be seen from the following table that the experimental A387 Gr 11 CL2 steel plate is subjected to weak water cooling after normalizing to greatly increase the strength and expand the post-heat treatment process adjustment window.
Normalizing temperature / °C | Normalizing time / min | cooling method | Rp0.2/MPa | Rm/MPa | A/% |
920 | 40 | Air cooling | 297 | 621 | 26.5 |
920 | 40 | Weak water cooling | 720 | 1020 | 19 |
The picture shows the typical metallographic structure of the hydrogen-positive A387 Gr 11 CL2 steel plate at 920 °C after normalizing. After air cooling, the microstructure is typical ferrite + pearlite structure. After weak water cooling treatment, the microstructure is lath bainite structure, so A387 Gr 11 CL2 The strength of the steel plate is greatly improved. The weak water cooling treatment after normalizing caused a fundamental change in the microstructure of A387 Gr 11 CL2 steel plate. Different organizations determined the subsequent heat treatment process of the experimental steel plate, the mechanical properties of the simulated post-weld heat treatment and the ability to resist embrittlement.