X65 pipe line steel and production method thereof

Abstract

The invention provides X65 pipe line steel and a production method thereof. The X65 pipe line steel comprises the following chemical components in percentage by weight: 0.055 to 0.090 percent of C, 0.15 to 0.35 percent of Si, 1.50 to 1.65 percent of Mn, less than or equal to 0.005 percent of S, less than or equal to 0.020 percent of P, 0.040 to 0.055 percent of Nb, 0.040 to 0.070 percent of V, 0.010 to 0.025 percent of Ti, less than or equal to 0.008 percent of N, 0.005 to 0.060 percent of Als, and the balance Fe and inevitable impurities. After heating and descaling, rough rolling and finishrolling are continuously completed on the same double-rack compact steckel mill, the reinforcing effect of Nb, V and other microalloyed elements added in the steel can be sufficiently played by delaycontrolled rolling in the rolling process, a micro-uniform tissue can be obtained, the occurrence of mixed crystals can be effectively prevented, and the strength and toughness of the X65 pipe line steel can be greatly improved. The produced X65 pipe line steel belongs to the product with high technology content and high additional value, and has remarkable economic benefit.

Description

technical field

[0001] The invention relates to an X65 pipeline steel, in particular to an X65 pipeline steel used for transporting oil and natural gas and a production method thereof, belonging to the technical field of metal material processing and forming. Background technique

[0002] Pipeline transportation of oil and gas has the characteristics of high efficiency, economy, safety, and no pollution. It is the most effective tool for oil and gas transportation. In recent years, with the rapid development of pipeline engineering, the production of pipeline steel has been greatly increased, and the production of pipeline steel has developed rapidly. Among them, X65 grade pipeline steel is a common steel grade for pipeline engineering, especially branch line engineering, and its production technology has been greatly developed. At present, domestic enterprises producing X65 pipeline steel adopt different processes. For example, the conventional semi-continuous hot rolling...

Examples

Embodiment 1

[0049] A. The slab with the following chemical composition: C 0.06wt%, Si 0.20wt%, Mn 1.58wt%, S 0.004wt%, P 0.018wt%, Nb 0.045wt%, V 0.050wt%, Ti 0.1wt%, N 0.007wt%, Als 0.030wt%, and the rest are Fe and unavoidable impurities, which are sent to a heating furnace with a temperature of 1230°C in the soaking section and heated for 250 minutes, wherein the heating of the slab in the soaking section The time is 60 minutes to ensure that the micro-alloying elements such as Nb and V precipitated in the slab are fully re-dissolved, the austenite grains are refined and the controlled cooling precipitation after rolling is prepared, the internal structure of the slab is uniform, and the furnace is released;

[0050] B. Use high-pressure water with a pressure of 18MPa to spray water on the front and back sides of the slab to descale for 12 seconds;

[0051] C. Send the descaled slab to the furnace coil rolling mill for rolling, and control the rolling start temperature to 1100°C, carry...

Embodiment 2

[0056]A. The slab with the following chemical composition: C 0.09wt%, Si 0.35wt%, Mn 1.65wt%, S 0.003wt%, P 0.015wt%, Nb 0.055wt%, V 0.07wt%, Ti 0.01wt%, N 0.005wt%, Als 0.005wt%, the rest is Fe and unavoidable impurities; it is sent to a heating furnace with a furnace temperature of 1270°C in the soaking section, and heated for 150 minutes, of which, the time for the slab in the soaking section 40 minutes to ensure that the microalloy elements such as Nb and V precipitated in the slab are fully re-dissolved, refine the austenite grains and prepare for the controlled cooling precipitation after rolling, uniform the internal structure of the slab, and release from the furnace;

[0057] B. Use high-pressure water with a pressure of 20MPa to spray water on the front and back sides of the slab to descale for 10 seconds;

[0058] C. Send the descaled slab to the furnace coil rolling mill for rolling, and control the rolling start temperature to 1200°C, conduct 4 passes of continuou...

Embodiment 3

[0063] A. The slab with the following chemical composition: C 0.055wt%, Si 0.15wt%, Mn 1.5wt%, S 0.003wt%, P 0.015wt%, Nb 0.04wt%, V 0.04wt%, Ti 0.25wt%, N 0.005wt%, Als 0.06wt%, the rest is Fe and unavoidable impurities; it is sent to a heating furnace with a temperature of 1250°C in the soaking section, and heated for 200 minutes, of which, the time for the slab in the soaking section 50 minutes to ensure that the microalloy elements such as Nb and V precipitated in the slab are fully re-dissolved, refine the austenite grains and prepare for the controlled cooling precipitation after rolling, uniform the internal structure of the slab, and release from the furnace;

[0064] B. Use high-pressure water with a pressure of 15MPa to spray water on the front and back sides of the slab to descale for 15 seconds;

[0065] C. Send the descaled slab to the furnace coil rolling mill for rolling, and control the rolling start temperature to 1150°C, conduct continuous rough rolling for 5...

technical field

[0001] The invention relates to an X65 pipeline steel, in particular to an X65 pipeline steel used for transporting oil and natural gas and a production method thereof, belonging to the technical field of metal material processing and forming. Background technique

[0002] Pipeline transportation of oil and gas has the characteristics of high efficiency, economy, safety, and no pollution. It is the most effective tool for oil and gas transportation. In recent years, with the rapid development of pipeline engineering, the production of pipeline steel has been greatly increased, and the production of pipeline steel has developed rapidly. Among them, X65 grade pipeline steel is a common steel grade for pipeline engineering, especially branch line engineering, and its production technology has been greatly developed. At present, domestic enterprises producing X65 pipeline steel adopt different processes. For example, the conventional semi-continuous hot rolling...

Examples

Embodiment 1

[0049] A. The slab with the following chemical composition: C 0.06wt%, Si 0.20wt%, Mn 1.58wt%, S 0.004wt%, P 0.018wt%, Nb 0.045wt%, V 0.050wt%, Ti 0.1wt%, N 0.007wt%, Als 0.030wt%, and the rest are Fe and unavoidable impurities, which are sent to a heating furnace with a temperature of 1230°C in the soaking section and heated for 250 minutes, wherein the heating of the slab in the soaking section The time is 60 minutes to ensure that the micro-alloying elements such as Nb and V precipitated in the slab are fully re-dissolved, the austenite grains are refined and the controlled cooling precipitation after rolling is prepared, the internal structure of the slab is uniform, and the furnace is released;

[0050] B. Use high-pressure water with a pressure of 18MPa to spray water on the front and back sides of the slab to descale for 12 seconds;

[0051] C. Send the descaled slab to the furnace coil rolling mill for rolling, and control the rolling start temperature to 1100°C, carry...

Embodiment 2

[0056]A. The slab with the following chemical composition: C 0.09wt%, Si 0.35wt%, Mn 1.65wt%, S 0.003wt%, P 0.015wt%, Nb 0.055wt%, V 0.07wt%, Ti 0.01wt%, N 0.005wt%, Als 0.005wt%, the rest is Fe and unavoidable impurities; it is sent to a heating furnace with a furnace temperature of 1270°C in the soaking section, and heated for 150 minutes, of which, the time for the slab in the soaking section 40 minutes to ensure that the microalloy elements such as Nb and V precipitated in the slab are fully re-dissolved, refine the austenite grains and prepare for the controlled cooling precipitation after rolling, uniform the internal structure of the slab, and release from the furnace;

[0057] B. Use high-pressure water with a pressure of 20MPa to spray water on the front and back sides of the slab to descale for 10 seconds;

[0058] C. Send the descaled slab to the furnace coil rolling mill for rolling, and control the rolling start temperature to 1200°C, conduct 4 passes of continuou...

Embodiment 3

[0063] A. The slab with the following chemical composition: C 0.055wt%, Si 0.15wt%, Mn 1.5wt%, S 0.003wt%, P 0.015wt%, Nb 0.04wt%, V 0.04wt%, Ti 0.25wt%, N 0.005wt%, Als 0.06wt%, the rest is Fe and unavoidable impurities; it is sent to a heating furnace with a temperature of 1250°C in the soaking section, and heated for 200 minutes, of which, the time for the slab in the soaking section 50 minutes to ensure that the microalloy elements such as Nb and V precipitated in the slab are fully re-dissolved, refine the austenite grains and prepare for the controlled cooling precipitation after rolling, uniform the internal structure of the slab, and release from the furnace;

[0064] B. Use high-pressure water with a pressure of 15MPa to spray water on the front and back sides of the slab to descale for 15 seconds;

[0065] C. Send the descaled slab to the furnace coil rolling mill for rolling, and control the rolling start temperature to 1150°C, conduct continuous rough rolling for 5...

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