Production process for online solid solution of stainless steel plate

Abstract

The invention discloses a production process for online solid solution of a stainless steel plate. Comprising the steps of heating, rolling, on-line chamber type furnace uniform-temperature softening and on-line solid solution. Wherein the temperature of the rolled steel plate is 850-1050 DEG C; the rolled steel plate is subjected to heat compensation in an online chamber type furnace to reach the solid solution temperature of 1050-1150 DEG C, the heat preservation time is 90-750 s, the surface temperature difference is controlled to be + / -15 DEG C, work hardening is eliminated, and component homogenization is achieved; and after heat preservation is completed, the steel plate is cooled to 50-120 DEG C in an immersed quenching machine. The production cost advantage is obvious, the production energy consumption is reduced by 20% or above compared with a traditional process, and the popularization prospect is wide.

Description

Technical Field

[0001] The invention relates to the technical field of stainless steel plates, and in particular to a production process for online solid solution of stainless steel plates. Background Art

[0002] Austenitic stainless steel plates are usually delivered in a solid solution state. At present, manufacturers mainly use offline solid solution treatment process, which requires the hot-rolled stainless steel plates to be heated from room temperature to the solid solution temperature (usually 1050-1100℃) and kept warm for a certain period of time, so that carbides and various alloy elements are completely and evenly dissolved in austenite, and then quickly quenched to improve the corrosion resistance, strength and impact toughness of stainless steel. The offline solid solution treatment process requires a lot of energy for heating. The whole process of stainless steel plate consumes more than 250m 3 Natural gas, the consumption of heating treatment for offline solid solution alone is more than 50m 3 Natural gas. Some manufacturers use ultra-fast cooling after hot rolling, but the microstructure, impact toughness and corrosion resistance of the treated steel plates cannot meet the requirements of downstream customers. Summary of the invention

[0003] In order to overcome the above-mentioned defects, the object of the present invention is to provide an online solution production process for stainless steel plates which can effectively and stably improve the corrosion resistance, strength and impact toughness of stainless steel and control stability.

[0004] To achieve the above-mentioned purpose, the production process of online solid solution of stainless steel plate of the present invention comprises the steps of heating, rolling, online chamber furnace temperature uniform softening and online solid solution; wherein,

[0005] The temperature of the steel plate after rolling is 850~1050℃;

[0006] The rolled steel plate is heated in an online chamber furnace to a solution temperature of 1050-1150°C for 90-750s.

[0007] The surface temperature is controlled with a temperature difference of ±15°C to eliminate work hardening and achieve composition homogenization; after the insulation is completed, the steel plate is cooled to 50-120°C in an immersion quenching machine.

[0008] Furthermore, the rolling is performed by using a reversible four-roller rolling mill.

[0009] Furthermore, the reversible four-roll rolling mill is a 3500 reversible four-roll rolling mill.

[0010] Furthermore, the rolling is performed by using a 3500 reversible four-roll rolling mill and multiple 2250 four-roll rolling mills.

[0011] Furthermore, when the rolled steel plate has a thickness of less than 50 mm and a width of 1200 to 2100 mm, a 3500 reversible four-roll rolling mill + 7 2250 four-roll rolling mills are used.

[0012] Furthermore, an online chamber furnace and an immersion quenching machine are arranged at the outlet side of the 3500 reversible four-roll mill, and an online chamber furnace and an immersion quenching machine are arranged at the outlet side of the seven 2250 four-roll mills, for controlling the temperature to realize online solid solution.

[0013] Furthermore, the immersion quenching machine is provided with an upper squeeze roller that can move up and down, the moving stroke of the upper squeeze roller is greater than 120mm, it is opened when the steel plate passes through, and closed after the steel plate passes through; the upper and lower circulation nozzles overlap at an angle of 5-15 degrees, and the sprayed liquid column forms an angle of 75-90 degrees with the forward direction of the steel plate, so that multiple vortex rings are formed on the upper and lower surfaces of the steel plate; the steel plate travels at a speed of 0.6-60m / min in the quenching machine; the liquid level of the quenching machine is controlled in this way to evenly cool the steel plate.

[0014] Furthermore, the steel plate has a thickness of 6 to 100 mm, a width of 1200 to 3300 mm, and a length of 3000 to 18500 mm.

[0015] The present invention makes full use of the waste heat after the steel plate is rolled, while the stainless steel plate produced by the existing offline solid solution needs to be hoisted to the annealing furnace and heated from room temperature to the solid solution temperature of 1050-1150°C for 15-60 minutes. Compared with the existing offline solid solution production, the online solid solution production process of the present invention greatly reduces the solid solution time and saves more than 20% of energy consumption (including the whole process from steelmaking molten steel to solid solution plate). DETAILED DESCRIPTION

[0016] The embodiments of the present invention are described in detail below.

[0017] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientation or positional relationships, are based on orientation or positional relationships and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0018] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0019] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] Example 1

[0021] The online solution production process of the rough-rolled stainless steel plate of this embodiment includes the following steps.

[0022] Heating and rolling: 304 austenitic stainless steel continuous casting billet with dimensions of 220mm×2100×2500mm (thickness×width×length) is heated to 1200℃ in a heating furnace. The continuous casting billet coming out of the heating furnace is rolled after being dephosphorized by high-pressure water. The starting rolling temperature is about 1150℃. The billet is rolled back and forth 15 times on a 3500mm four-roll mill. The final rolling temperature of the steel plate is 950℃. The outlet thickness is 10mm. The billet is rolled into a steel plate of 10mm×3200mm×36000mm (thickness×width×length).

[0023] Online chamber furnace uniform temperature softening and solution treatment: The steel plates are cut into two pieces of 10mm×3200mm×18000mm by a segmented cutting machine. The residual temperature of the steel plates before entering the furnace is about 800℃. They are heated to 1050℃ in the solution furnace and kept warm for 500s. Then they are quickly cooled in the quenching machine and quenched to 80℃.

[0024] Example 2

[0025] An online solution production process for rough rolling + 7-stand finishing rolling stainless steel plates in one embodiment includes the following steps.

[0026] Heating and rolling: 306 austenitic stainless steel continuous casting billet with dimensions of 200mm×2100×12000mm (thickness×width×length) is heated to 1250℃ in a heating furnace. The continuous casting billet coming out of the heating furnace is rolled after dephosphorization with high-pressure water. The starting rolling temperature is about 1220℃. It is reciprocated and rolled for 9 times on a 3500mm four-roll mill and continuously rolled for 7 times on a 2250mm four-roll mill. The final rolling temperature of the steel plate is 980℃, and the outlet thickness is 6mm. The cast billet is rolled into a steel plate of 6mm×2100mm×40000mm (thickness×width×length);

[0027] Online chamber furnace uniform temperature softening and solution treatment: The steel plates are cut into 4 pieces of 6mm×2100mm×10000mm by a segmented cutting machine. The residual temperature of the steel plates before entering the furnace is about 750℃. They are heated to 1050℃ in the solution furnace and kept warm for 200s. Then they are quickly cooled in the quenching machine and quenched to 120℃.

[0028] The present invention is described in detail above, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the present invention. Many other changes and modifications that do not depart from the concept and scope of the present invention should be regarded as the protection scope of the present invention.

[0029] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0030] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A production process for online solution treatment of stainless steel plates, characterized in that: The process includes heating, rolling, online chamber furnace temperature softening and online solution treatment; wherein, The temperature of the steel plate after rolling is 850~1050℃; The rolled steel plate is heated in an online chamber furnace to a solution temperature of 1050-1150°C for 90-750s. The surface temperature is controlled with a temperature difference of ±15°C to eliminate work hardening and achieve composition homogenization; after the insulation is completed, the steel plate is cooled to 50-120°C in an immersion quenching machine.

2. The production process of online solid solution of stainless steel plate according to claim 1, characterized in that: The rolling is performed by using a reversible four-roller rolling mill.

3. The production process of online solutionizing of stainless steel plate according to claim 2, characterized in that: The reversible four-roller rolling mill is a 3500 reversible four-roller rolling mill.

4. The production process of online solutionizing of stainless steel plate according to claim 2, characterized in that: The rolling is completed by using a 3500 reversible four-roller rolling mill and multiple 2250 four-roller rolling mills.

5. The production process of online solutionizing of stainless steel plate according to claim 2, characterized in that: When the rolled steel plate has a thickness of less than 50 mm and a width of 1200 to 2100 mm, a 3500 reversible four-roll rolling mill + 7 2250 four-roll rolling mills are used.

6. The production process of online solutionizing of stainless steel plate according to claim 5, characterized in that: An online chamber furnace and an immersion quenching machine are arranged at the outlet side of the 3500 reversible four-roll mill, and an online chamber furnace and an immersion quenching machine are arranged at the outlet side of the seven 2250 four-roll mills, for controlling the temperature to realize online solid solution.

7. The production process of online solutionizing of stainless steel plate according to claim 1, characterized in that: The immersion quenching machine is provided with an upper squeeze roller that can move up and down, the upper squeeze roller has a moving stroke greater than 120mm, is opened when the steel plate passes through, and is closed after the steel plate passes through; the upper and lower circulation nozzles overlap at an angle of 5-15 degrees, and the sprayed liquid column forms an angle of 75-90 degrees with the forward direction of the steel plate, so that multiple vortex rings are formed on the upper and lower surfaces of the steel plate; the steel plate travels at a speed of 0.6-60m / min in the quenching machine; the liquid level of the quenching machine is controlled in this way to evenly cool the steel plate.

8. The production process of online solutionizing of stainless steel plate according to claim 1, characterized in that: The steel plate has a thickness of 6 to 100 mm, a width of 1200 to 3300 mm, and a length of 3000 to 18500 mm.