Production process of large-piece-weight extra-thick chromium molybdenum steel plate

Abstract

The invention discloses a production process of a large-piece-weight extra-thick chromium molybdenum steel plate. The production process comprises the steps of forging, preheating, heating and rolling, wherein the preheating procedure comprises the steps of heating a forged blank to 180-200 DEG C at a heating rate of less than or equal to 30 DEG C / h after the forged blank is placed in a furnace, simmering the steel for 4-5 hours with soft fire, then heating the steel in the furnace with the temperature raised to 400-450 DEG C at a heating rate of less than or equal to 50 DEG C / h, keeping thetemperature for more than or equal to 10 hours, and discharging the steel plate from the furnace. After the process is adopted, the blank and the finished steel plate do not have defects such as rupture and cracking, forging defects such as surface cracks, slag inclusion and internal tearing are effectively eliminated, and the forged blank and the steel plate have smooth surfaces, good quality andwide application value.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, in particular to a production process of a large single-weight extra-thick chromium-molybdenum steel plate. Background technique [0002] The large unit weight and extra-thick chrome-molybdenum steel plate produced by the combination of "forging + rolling" meets the domestic petrochemical industry's demand for plates for key equipment in coal chemical and petrochemical industries such as thick-walled hydrogenation reactors. It is of great practical significance to break the monopoly of foreign countries and reduce the cost of extra-thick chromium-molybdenum steel plates using traditional forging methods. However, due to the excessive weight and thickness of the steel plate produced by the "forging + rolling" method, as well as the width and length of the steel plate, the precise connection of various important processes must be considered, otherwise it is very easy to go unplanned. For exampl...

AI Technical Summary

Problems solved by technology

However, due to the excessive weight and thickness of the steel plate produced by the "forging + rolling" method, as well as the width and length of the steel plate, it is necessary to consider the precise connection of various important processes, otherwise it is very easy to cause unplanned

For example, after forging, the billet is cooled and put directly into the furnace for heating and rolling. The billet or steel plate is easily cracked or even broken, which directly leads to the scrapping of the billet or steel plate, and serious loss of manpower and material resources.

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