High-toughness steel plate used in extremely cold environment and manufacturing method thereof

Abstract

The invention discloses a high-toughness steel plate used in an extremely cold environment. The high-toughness steel plate comprises the following chemical elements in percentage by mass: 0.05-0.16% of C; 0.60%-1.2% of Si; 0.40% to 1.20% of Mn; 0.30% to 1.00% of Cr; 0.40% to 1.00% of Ni; 0.01% to 0.10% of Ti; 0% to 0.60% of Mo; 0.30% to 0.80% of Cu; 0.01% to 0.06% of Al; 0.003%-0.06% of Nb, 0%-0.08% of V and the balance Fe and other inevitable impurities. In addition, the invention also discloses a manufacturing method of the high-toughness steel plate, which comprises the following steps: (1)smelting and casting; (2) heating; (3) rolling; and (4) quenching and tempering. The high-toughness steel plate has the characteristics of high strength, high toughness, excellent weldability, good surface quality and stable whole plate performance.

Description

technical field

[0001] The invention relates to a steel plate and a manufacturing method thereof, in particular to a high-toughness steel plate and a manufacturing method thereof. Background technique

[0002] Ships built for polar regions need to be used in low-temperature and cold seas, and the marine environment is complex and changeable, so they have to withstand many challenges brought about by ultra-low temperature, ice and snow abrasion, low-temperature wind wave collision, strong ocean storm and frozen soil collision. The design, material selection, construction and processing of low-temperature steel for ships have put forward higher requirements. Therefore, the low-temperature steel used in polar ships requires excellent comprehensive performance in extreme cold and low temperature, and its structural materials not only need to have high strength and good plasticity, but also need to have excellent impact toughness at -60°C and -80°C , especially in the ultra-low ...

Examples

Embodiment 1-7

[0057] The high-toughness steel plate used under the extremely cold environment of the above-mentioned embodiments 1-7 is obtained by the following steps:

[0058] (1) Smelting and casting are carried out according to the chemical composition shown in Table 1.

[0059] (2) Heating: Heat the billet to 1000-1250°C, the billet heating and holding time is ≤1.5min / mm, the total heating and holding time is ≤450min, and the holding time at the high temperature section of 930°C-1250°C is ≤200min.

[0060] (3) Rolling: Control the final rolling temperature to ≥950°C, the reduction rate of each pass to be ≥8%, and air-cool to room temperature after rolling.

[0061] (4) Quenching + tempering: In the quenching step, heat to 830°C-930°C, the heating time is controlled at 1.2-1.5min / mm, and the heating time is not less than 30min, and water quenching is used to cool to below 300°C. Then air-cool; in the tempering step, heat to 530-690°C for a period of time, then air-cool. Among them, in...

technical field

[0001] The invention relates to a steel plate and a manufacturing method thereof, in particular to a high-toughness steel plate and a manufacturing method thereof. Background technique

[0002] Ships built for polar regions need to be used in low-temperature and cold seas, and the marine environment is complex and changeable, so they have to withstand many challenges brought about by ultra-low temperature, ice and snow abrasion, low-temperature wind wave collision, strong ocean storm and frozen soil collision. The design, material selection, construction and processing of low-temperature steel for ships have put forward higher requirements. Therefore, the low-temperature steel used in polar ships requires excellent comprehensive performance in extreme cold and low temperature, and its structural materials not only need to have high strength and good plasticity, but also need to have excellent impact toughness at -60°C and -80°C , especially in the ultra-low ...

Examples

Embodiment 1-7

[0057] The high-toughness steel plate used under the extremely cold environment of the above-mentioned embodiments 1-7 is obtained by the following steps:

[0058] (1) Smelting and casting are carried out according to the chemical composition shown in Table 1.

[0059] (2) Heating: Heat the billet to 1000-1250°C, the billet heating and holding time is ≤1.5min / mm, the total heating and holding time is ≤450min, and the holding time at the high temperature section of 930°C-1250°C is ≤200min.

[0060] (3) Rolling: Control the final rolling temperature to ≥950°C, the reduction rate of each pass to be ≥8%, and air-cool to room temperature after rolling.

[0061] (4) Quenching + tempering: In the quenching step, heat to 830°C-930°C, the heating time is controlled at 1.2-1.5min / mm, and the heating time is not less than 30min, and water quenching is used to cool to below 300°C. Then air-cool; in the tempering step, heat to 530-690°C for a period of time, then air-cool. Among them, in...

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