High-quality alloy steel bar and production process thereof

Abstract

The invention belongs to the field of alloys, in particular to a high-quality alloy steel bar and a production process thereof. The high-quality alloy steel bar comprises the following components in percentage by weight: 0.10 to 0.50 percent of C, 0.10 to 1.50 percent of Cr, 0.50 to 1.50 percent of Mn, 0.010 to 0.015 percent of Ti, less than or equal to 0.40 percent of Si, less than or equal to 0.035 percent of P, less than or equal to 0.035 percent of S, 0.020 to 0.050 percent of Al, less than or equal to 0.020 percent of N, less than or equal to 0.03 percent of Mo, 0.05 to 0.50 percent of V, less than 0.030 percent of Ni, less than or equal to 0.090 percent of Cu, less than or equal to 0.0018 percent of B, less than or equal to 0.0014 percent of O and the balance of Fe and inevitable impurities. In the process, a crystallizer electromagnetic stirring mode is adopted, the current intensity of crystallizer electromagnetic stirring equipment is 0 to 550A, the frequency of the crystallizer electromagnetic stirring equipment is 2 to 4Hz, the solidified end section is slightly rolled and the rolling reduction is 3 to 9 millimeters. In the invention, the internal quality of casting blanks can be improved obviously, and the central looseness and composition segregation of the cast blanks can be reduced.

Description

Technical field [0001] The invention belongs to the field of metallurgy and relates to a high-quality composite steel bar and its production process. Background technique [0002] Generally, when casting alloy steel bars, the center porosity and composition segregation of the cast slab are prone to occur. In severe cases, the center porosity can reach level 2 or more, and even exceed level 3 required by the standard. Band segregation occurs due to electromagnetic stirring. The difference in carbon content of the slab section reaches 20% of the melting composition. Sampling and checking the chemical composition of the finished product after rolling shows that the composition of the cross section has a large difference and is easy to fail. When sampling and inspecting hardenability, the difference between different faces at the same position is relatively large (there are many positions where the difference is greater than 4HRC). The content of C in each area of ​​16CrMnBH tested...

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Problems solved by technology

Sampling and testing the chemical composition of the finished product after rolling ...

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