Direct sending and loading process of T91 steel continuous casting billet

Abstract

The invention discloses a direct sending and loading process of a T91 steel continuous casting billet. The T91 steel continuous casting billet is produced by a continuous casting machine and then conveyed to a roller way of a walking beam furnace to be cooled, and the cooling speed is controlled to be 1-2 DEG C/s; when the surface temperature of the continuous casting billet is reduced to be about 450 DEG C, the continuous casting billet is subjected to warming up treatment for 5-10 min and then is conveyed to the heating furnace to be heated, and the optimal quality is ensured when the continuous casting billet is loaded into the furnace and after the continuous casting billet is heated. The direct sending and loading process of the T91 steel continuous casting billet overcomes the defect of corner cracks caused when high-intensity T91 steel continuous casting billets are subjected to hot charging at the temperature lower than the martensite transformation temperature, optimizes the processing performance after the T91 steel continuous casting billet is heated and reduces energy consumption.

Description

technical field [0001] The invention belongs to the technical field of metal material processing, and in particular relates to a direct loading process of high-strength and high-alloy steel continuous casting billets, specifically a direct loading process of T91 steel continuous casting billets. Background technique [0002] T91 steel has a large amount of alloy elements, and it needs to be fully solidified during heat treatment, and martensitic transformation can occur after air cooling, and the structure has high strength and hardness after quenching. Most steel mills use continuous casting round billets when producing T91 tube billets. Compared with square billets, round billets are more prone to defects such as cracks when the billet shell solidifies, which makes it more difficult to control the continuous casting process; adopting cold charging process will increase the solid solution time of the alloy , increasing the time in the furnace reduces the efficiency of the h...

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Problems solved by technology

Most steel mills use continuous casting round billets when producing T91 tube billets. Compared with square billets, round billets are more prone to defects such as cracks when the billet shell solidifies, which makes it more difficult to control the continuous casting process; adopting cold charging process will increase the solid solution time of the alloy , increasing the time in the furnace reduces the efficiency of the heating furnace and increases the energy consumption rate by 30%. Production efficiency; when some steel mills directly heat T91 steel continuous casting billets to the heating furnace, the billet hot charging temperature range is large, and a lower temperature of about 400 ° C is used for hot charging. The superposition of variable stress and thermal stress produces corner crack defects. If hot charging is carried out at a temperature of about 600 ° C or higher, it will easily lead to coarse grains, high microstructure and hardness, and poor processing plasticity

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