Method for improving tempering efficiency of Q1100E ultrahigh-strength steel

Abstract

The invention discloses a method for improving the tempering efficiency of Q1100E ultrahigh-strength steel, and relates to the technical field of steel plate production, the method comprises the following steps: plate selection: selecting two quenched Q1100E steel plates; the two steel plates are stacked in the thickness direction; tempering, wherein the two stacked steel plates are placed in a heat treatment furnace to be subjected to tempering treatment; and straightening: carrying out strong cold straightening on the tempered steel plate to obtain a finished steel plate. The tempering efficiency of the high-strength Q1100E is improved by 20% or above, energy consumption is reduced, tempering resources are released, and meanwhile the mechanical property and the plate shape flatness of the obtained steel plate meet the use requirements of customers.

Description

Technical Field

[0001] The invention relates to the technical field of steel plate production, and in particular to a method for improving the tempering efficiency of Q1100E ultra-high strength steel. Background Art

[0002] Q1100E ultra-high strength steel is mainly used to manufacture key components of large-scale engineering machinery and equipment such as automobile crane booms and crawler crane pull plates, which places high demands on the strength and toughness matching of steel plates and bending consistency. Q1100E is a low-temperature tempered steel. In order to reduce the internal stress level of the steel plate and improve the bending consistency, the tempering heating time is relatively long. The tempering cycle of a steel plate takes more than one hour, resulting in low production efficiency and high energy costs.

[0003] There are few studies on improving the tempering efficiency of ultra-high-strength steel. For example, patent CN114277307B discloses "a 1100MPa-grade high-strength steel for engineering machinery and its production method", which studies the influence of rapid heat treatment on the structure and performance of ultra-high-strength steel, but does not consider the plate shape after heat treatment and user performance; patent application CN117904408A discloses "a flash heat treatment process for ultra-high-strength steel plates", and the rolled steel plates need to undergo three heat treatment steps at 600-650℃, 900-950℃, and 150-250℃. There are many process flows and a long production cycle. Patent CN114196802 A discloses "a heat treatment process suitable for steel plate production", but it only targets steel plates ≤20mm and requires the steel plates to be of the same specifications, making the production organization inflexible. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for improving the tempering efficiency of Q1100E ultra-high strength steel.

[0005] In order to solve the above technical problems, the technical solution of the present invention is as follows: A method for improving the tempering efficiency of Q1100E ultra-high strength steel, comprising: Plate selection: Select two quenched Q1100E steel plates; Lamination: stacking two steel plates in the thickness direction; Tempering: Put the two stacked steel plates into a heat treatment furnace for tempering; Straightening: The steel plate after tempering is subjected to strong cold straightening to obtain the finished steel plate.

[0006] As a preferred solution of the method for improving the tempering efficiency of Q1100E ultra-high strength steel described in the present invention, the thickness difference between the two quenched Q1100E steel plates is less than or equal to 2 mm, and the length difference and width difference are both less than or equal to 200 mm.

[0007] As a preferred solution of the method for improving the tempering efficiency of Q1100E ultra-high strength steel of the present invention, the horizontal spacing between any side edges of the two stacked steel plates is less than or equal to 100 mm.

[0008] As a preferred solution of the method for improving the tempering efficiency of Q1100E ultra-high strength steel described in the present invention, the tempering temperature of the tempering treatment is 150-180°C, the heating coefficient is 3.6-3.8min / mm, and the holding time is 40-60min.

[0009] As a preferred solution of the method for improving the tempering efficiency of Q1100E ultra-high strength steel described in the present invention, the time the steel plate is in the furnace during the tempering treatment is: heating coefficient*total thickness after stacking+insulation time.

[0010] As a preferred solution of the method for improving the tempering efficiency of Q1100E ultra-high strength steel described in the present invention, the yield strength of the finished steel plate is ≥1100MPa, the tensile strength is ≥1200MPa, the elongation is ≥9%, and the -40°C impact value is ≥30J.

[0011] As a preferred solution of the method for improving the tempering efficiency of Q1100E ultra-high strength steel of the present invention, the unevenness of the finished steel plate satisfies 3 mm / m and 5 mm / 2m.

[0012] The beneficial effects of the present invention are: The present invention improves the tempering efficiency of high-strength Q1100E by more than 20%, reduces energy consumption, and releases tempering resources. At the same time, the obtained steel plate mechanical properties and plate flatness meet the use requirements of customers. DETAILED DESCRIPTION

[0013] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific implementation methods.

[0014] The present application provides a method for improving the tempering efficiency of Q1100E ultra-high strength steel, which method comprises the following steps in sequence: Step S101: plate selection: select two quenched Q1100E steel plates.

[0015] It should be noted that the thickness difference between the two selected quenched Q1100E steel plates is less than or equal to 2 mm, and the length difference and width difference are both less than or equal to 200 mm.

[0016] Step S102: stacking: stacking two steel plates along the thickness direction.

[0017] Specifically, use a crane to stack two steel plates up and down and align them as much as possible.

[0018] It should be noted that it is necessary to ensure that the horizontal distance between any side edges of the two stacked steel plates is less than or equal to 100 mm.

[0019] Step S103: Tempering: The two stacked steel plates are placed in a heat treatment furnace for tempering.

[0020] Specifically, the process parameters of the tempering treatment are set as follows: tempering temperature is 150-180°C, heating coefficient is 3.6-3.8min / mm, and holding time is 40-60min. The time in the furnace is: heating coefficient*total thickness after stacking+holding time.

[0021] Step S104: Straightening: The steel plate after the tempering treatment is subjected to strong cold straightening to obtain a finished steel plate.

[0022] Specifically, in order to fully eliminate internal stress and ensure the flatness of the plate shape, the tempered steel plate is subjected to strong cold straightening.

[0023] The yield strength of the finished steel plate obtained by the above method is ≥1100MPa, the tensile strength is ≥1200MPa, the elongation is ≥9%, and the -40℃ impact value is ≥30J. The unevenness of the finished steel plate meets 3mm / m and 5mm / 2m.

[0024] The above scheme is described below through specific embodiments.

[0025] Embodiment 1: This embodiment provides a method for improving the tempering efficiency of Q1100E ultra-high strength steel, which specifically comprises the following steps: (1) Select one Q1100E quenched steel plate with the dimensions of 7.5*2150*14200mm and one with the dimensions of 9*2250*14000mm.

[0026] (2) Before entering the tempering furnace, stack the two steel plates up and down and use a crane to align the steel plates as much as possible with a deviation of no more than 100 mm.

[0027] (3) Set the process parameters of the laminate: tempering temperature is 155°C, heating coefficient is 3.8 min / mm, holding time is 40 min, and the time in the furnace is 3.8*(7.5+9)+40=102.7 min.

[0028] (4) The two stacked steel plates are sent into a heat treatment furnace for tempering.

[0029] (5) After tempering, the steel plate is straightened 3 times using a 9-roller high-force cold straightening machine.

[0030] The mechanical properties and 1m and 2m roughness of the steel plate obtained in this example were measured and compared with a single steel plate. The specific details are shown in Table 1 below.

[0031]

[0032] Table 1 It can be seen from Table 1 that the mechanical properties and roughness of the steel plate obtained in this embodiment are basically the same as those of the single-plate tempered steel plate, and the users of the steel plate have good feedback.

[0033] This embodiment adopts the method of stacked plate tempering. Compared with single plate tempering, the tempering time is shortened by 40 minutes, the tempering efficiency is increased by 28%, and the energy consumption is reduced by 28%.

[0034] Embodiment 2: This embodiment provides a method for improving the tempering efficiency of Q1100E ultra-high strength steel, which specifically comprises the following steps: (1) Select one Q1100E quenched steel plate with the dimensions of 25*2200*9600mm and one Q1100E quenched steel plate with the dimensions of 25*2200*9400mm.

[0035] (2) Before entering the tempering furnace, stack the two steel plates up and down and use a crane to align the steel plates as much as possible with a deviation of no more than 100 mm.

[0036] (3) Set the process parameters of the laminate: tempering temperature is 170°C, heating coefficient is 3.6 min / mm, holding time is 60 min, and the time in the furnace is 3.6*(25+25)+60=240 min.

[0037] (4) The two stacked steel plates are sent into a heat treatment furnace for tempering.

[0038] (5) After tempering, the steel plate is straightened once using a 9-roller high-force cold straightening machine.

[0039] The mechanical properties and 1m and 2m roughness of the steel plate obtained in this example were measured and compared with a single steel plate. The specific details are shown in Table 2 below.

[0040]

[0041] Table 2 It can be seen from Table 2 that the mechanical properties and roughness of the steel plate obtained in this embodiment are basically the same as those of the single-plate tempered steel plate, and the users of the steel plate have good feedback.

[0042] This embodiment adopts the method of stacked plate tempering. Compared with single plate tempering, the tempering time is shortened by 60 minutes, the tempering efficiency is increased by 20%, and the energy consumption is reduced by 20%.

[0043] Therefore, the technical solution of the present application increases the tempering efficiency of high-strength Q1100E by more than 20%, reduces energy consumption, and releases tempering resources. At the same time, the mechanical properties and flatness of the steel plate meet the customer's requirements.

[0044] In addition to the above embodiments, the present invention may also have other implementation modes; any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A method for improving the tempering efficiency of Q1100E ultra-high strength steel, characterized in that: include: Plate selection: Select two quenched Q1100E steel plates; Lamination: stacking two steel plates in the thickness direction; Tempering: Put the two stacked steel plates into a heat treatment furnace for tempering; Straightening: The steel plate after tempering is subjected to strong cold straightening to obtain the finished steel plate.

2. The method for improving the tempering efficiency of Q1100E ultra-high strength steel according to claim 1, characterized in that: The thickness difference between the two quenched Q1100E steel plates is less than or equal to 2 mm, and the length difference and width difference are both less than or equal to 200 mm.

3. The method for improving the tempering efficiency of Q1100E ultra-high strength steel according to claim 1, characterized in that: The horizontal distance between any side edges of the two stacked steel plates is less than or equal to 100 mm.

4. The method for improving the tempering efficiency of Q1100E ultra-high strength steel according to claim 1, characterized in that: The tempering temperature of the tempering treatment is 150-180° C., the heating coefficient is 3.6-3.8 min / mm, and the insulation time is 40-60 min.

5. The method for improving the tempering efficiency of Q1100E ultra-high strength steel according to claim 1, characterized in that: The time that the steel plate spends in the furnace during the tempering treatment is: heating coefficient*total thickness after stacking+holding time.

6. The method for improving the tempering efficiency of Q1100E ultra-high strength steel according to claim 1, characterized in that: The yield strength of the finished steel plate is ≥1100MPa, the tensile strength is ≥1200MPa, the elongation is ≥9%, and the impact value at -40°C is ≥30J.

7. The method for improving the tempering efficiency of Q1100E ultra-high strength steel according to claim 1, characterized in that: The unevenness of the finished steel plate meets 3mm / m and 5mm / 2m.

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