Production process of 690 MPa highly-reaming steel strip

Abstract

The invention discloses a production process of a 690 MPa highly-reaming steel strip. The production process includes the steps of converter smelting, LF furnace refining, slab continuous casting, heating, roughing, fining, cooling and coiling;, according to the fining process, the inlet temperature is 1040-1090 DEG C, and the finishing temperature is 830-880 DEG C; and according to the cooling process, the steel strip is rapidly cooled to 680-720 DEG C at a cooling speed of 35-50 DEG C / s through laminar cooling at the front coarse tuning stage, subjected to air cooling for 4-8 s at the middlestage, and then quickly cooled to 450-500 DEG C at the cooling speed of 20-30 DEG C / s through laminar cooling at the last fine tuning stage. According to the production process of the 690 MPa highly-reaming steel strip, a hot rolling temperature system and a cooling strategy are reasonably designed, the strengthening effect of niobium and titanium microalloys is fully performed, by adopting meanssuch as fine grain strengthening and precipitation strengthening, the steel of the grade has the high strength, and meanwhile, high reaming performance can be still ensured; and the production process can be used for manufacturing car parts in complex shapes, the thickness of adopted steel plates can be lowered, the vehicle weight is decreased, and vehicle fuel consumption is reduced.

Description

technical field

[0001] The invention relates to a production process of a hot-rolled steel strip, in particular to a production process of a 690MPa high-hole expansion steel strip. Background technique

[0002] With the increasing requirements of the automobile market for energy saving, environmental protection, safety, and comfort, the lightweight of automobile bodies has become an important development direction of today's automobile technology development. Because high-strength steel and ultra-high-strength steel can reduce the weight of the car body while improving the structural strength and energy absorption capacity of the car body, high-strength steel and ultra-high-strength steel are more and more widely used in cars. So far, high-strength steel and ultra-high-strength steel are still one of the most economical and effective ways to reduce weight.

[0003] The earliest research basis of high-hole expansion steel comes from traditional dual-phase steel. According to...