H13 round steel continuous casting and continuous rolling manufacturing process

Abstract

The invention relates to a continuous casting and continuous rolling manufacturing process of H13 round steel for hot working molds with specifications of phi 50 mm to phi 150 mm; the alloy content ofthe steel is 9%; arc billet continuous casting machines with sections above 300*400 mm are used for continuous casting; and a 850 reversible and continuous casting unit is used for rolling. As the alloy content of the steel is higher, the bad segregation, middle cracks and center cracks are easily generated in the solidification process, the deformation resistance in the continuous casting process is high, the surface rolling defects are easily generated, the welding is difficult in the rolling process due to internal looseness, the cracking phenomenon is easily generated through air coolingafter rolling, and the quality of rolled materials and final products is badly influenced. A continuous casting electromagnetic stirring technology, a light pressing technology and an ultraweak cold technology are applied, and such processes as high-temperature dispersion and belt temperature annealing are combined to effectively control the grade of belt structures, to prevent center cracks and surface cracks of continuous-cast blanks and cooling stress cracks of the rolled materials and to improve the ultrasonic flaw detection pass percent of the rolled materials and the pass percentage of the belt structures.

Description

Technical field [0001] The invention relates to a manufacturing process of round steel, in particular to a manufacturing process of H13 round steel continuous casting and rolling for hot work die with Φ50mm-Φ150mm. Background technique [0002] H13 steel belongs to air-cooled hardened steel and is one of the most representative hot work die steels. This steel has the advantages of good thermal strength, toughness, thermal fatigue performance, wear resistance and small heat treatment deformation. Due to the high alloy content of this steel and the high requirements for the band structure, most of the domestic production is carried out by die casting, electroslag remelting and forging, and the production cost is relatively high. [0003] The content of alloying elements in H13 steel is relatively high, reaching about 9%, and high-temperature thermoplasticity is low. Carbon and alloying elements are prone to severe segregation, especially the effect of chromium and vanadium, which ma...

AI Technical Summary

Problems solved by technology

[0006] Therefore, due to the high alloy content of H13 steel, severe segregation, intermediate cracks and central cracks are prone to occur during the solidification process, the deformation resistance is large during the continuous casting process, and surface rolling defects are prone to occur, and the internal looseness is not easy to be welded during the rolling process. , air cooling after rolling is prone to cracking, which seriously affects the quality of rolled materials and final products