A non-modulated production process of plastic mold steel thick plate

Abstract

The invention discloses a production technology of a non-modulated plastic die steel thick plate. The production technology comprises the following steps: converter smelting and ladle furnace (LF) and Ruhrstahl Heraeus (RH) refining are adopted to pour a continuous cast billet; the heating temperature is 1150-1200 DEG C, the precision rolling temperature is 900-950 DEG C, the finish rolling temperature is 860-900 DEG C; the cooling control of the steel plate is performed after the steel plate is rolled, the phase transformation strengthening and the precipitation strengthening of the microalloyed carbon nitride are utilized to ensure that when the section of the steel plate is not modulated, the structure and performance are uniform along the section, the plastic die steel of which section hardness is 300-340 is obtained; the rolled steel plate is tempered to eliminate the stress and avoid sawing crack, the hardness of the steel plate is uniform after tempering, and the section has granular bainite structure. In the production technology, the alloy component is controlled, Ni is not added, a small amount of Mo, B and V are added and the Cr content is increased properly, thus the steel plate has higher hardenability; and the cooling control of the rolled steel plate is performed to ensure that the large-section steel plate has bainite structure. The production technology is suitable for the production of the non-modulated plastic die steel thick plate, which is prepared from the 320mm continuous cast billet and of which thickness is less than 120mm.

Description

[0001] technical field [0002] The invention relates to a production process of plastic mold steel, in particular to a low-cost non-modulation plastic mold steel thick plate production process. Background technique [0003] With the rapid development of my country's plastic industry, the market demand for large-scale plastic mold steel is increasing. In order to improve the service life of the mold, the processing accuracy of the mold and the quality of plastic products, the quality requirements of the mold steel are getting higher and higher. [0004] Pre-hardened plastic mold steel refers to the advanced quenching and tempering treatment of the hot-processed steel plate, through quenching treatment and high-temperature tempering treatment, to obtain tempered sorbite structure, to reach the hardness range required by plastic mold steel, and then to carry out mold engraving Processing, no final heat treatment is required after the mold is formed, so as to avoid mold deforma...

AI Technical Summary

Problems solved by technology

[0007] In order to overcome the shortcomings of high manufacturing cost of pre-hardened plastic mold steel, long manufacturing cycle, high sensitivity to quenching cracks, and existing non-quenched and tempered plastic mold steel with more alloy elements, higher carbon equivalent, and uneven cross-section hardness, the purpose of the present invention It is to provide a low-cost non-modulated plastic mold steel thick plate production process

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