A kind of preparation method of hot straightening roll for medium and thick plate

Abstract

The invention discloses a preparation method of a medium-thickness plate hot straightening roll. The preparation method is characterized by comprising the following steps: 1. smelting of roll billet steel, wherein the steel comprises the following components in percentage by weight: 0.45-0.56% of C, 1.50-2.20% of Si, at most 0.15% of Mn, 8.00-13.50% of Cr, 1.50-2.50% of Mo, 0.80-1.80% of V, 0.20-0.30% of W, 0.10-0.40% of Nb, at most 0.020% of S, at most 0.025% of P, at most 0.50% of Ni, at most 0.20% of Cu and the balance of Fe; 2. ladle refining; 3. ingot casting; 4. roll billet forging, and annealing after forging; and 5. surface heat treatment. The medium-thickness plate hot straightening roll prepared by the preparation method can bear the high-temperature impact and abrasion, and high-temperature heat alternation and stress alternation fatigue.

Description

technical field [0001] The invention belongs to the field of thermal straightening machines for a production line of hot-rolled medium and thick plates, and in particular relates to a method for preparing a medium and thick plate thermal straightening roll. Background technique [0002] After the hot-rolled steel plate passes through the final rolling mill, it is straightened by a hot straightening unit in a hot state, so that the dimensional accuracy, shape and flatness of the steel plate can meet the requirements of the finished steel plate. Hot straightening rolls are used in hot-rolled steel plate production line hot-leveling units in various large-scale steel mills, and are the core key components of hot-leveling units. [0003] Domestic hot-rolled steel plate production lines, especially hot-rolled medium-thick steel plate hot-rolled production lines, have harsh working conditions in the hot straightening section. Variable thermal stress, so it is easy to cause the fa...

AI Technical Summary

Problems solved by technology

[0004] The surface hardness of 60CrMoV and 60CrMnMo is relatively high, which can reach HRC 60 and above, but the hardness decrease gradient in the effective hardened layer is relatively large, and the tempering stability is poor. The hardness stability is insufficient during thermal straightening, and the surface hardness changes greatly.

Regardless of the type, there are structural defects in the surfacing layer, which is prone to inhomogeneity, and the use effect is even worse, and some failures occur in about 10 days

Therefore, the quality life of the hot straightening rollers of the hot straightening unit of the hot rolled steel plate production line seriously restricts the production efficiency of the medium and heavy plate, and restricts the reduction of the cost of the production line

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