A wear-resistant steel plate with low temperature impact toughness and its preparation method

Abstract

The invention discloses a wear-resistant steel plate with high low-temperature impact toughness, and a preparation method thereof. The wear-resistant steel comprises he following chemical components with contents in percentage by weight: 0.13%-0.20% of C, 0.25%-0.60% of Si, 0.4%-0.8% of Mn, 0.15%-0.35% of Ni, 0.1%-0.3% of Mo, 0.25%-0.60% of Cr, 0.010%-0.035% of Ti, not greater than 0.015% of P, not greater than 0.003% of S, 0.0013%-0.0030% of B, 0.010%-0.050% of Al, not greater than 0.0002% of H, not greater than 0.0035% of N, and the balance Fe and inevitable inclusions, and the elements Cr and Ni meet the requirement that the total content of Cr and Ni is not greater than the sum of 1.807C, 1.077Si, 0.797Mn and 7.727B and not less than the sum of 0.933C, 0.45Si, 0.121Mn and 0.41B. The wear-resistant steel plate obtained through the preparation method disclosed by the invention is excellent in comprehensive performance; and the preparation method is simple, convenient and practical.

Description

technical field [0001] The invention belongs to the technical field of steel plate preparation. Specifically, the invention relates to a steel plate with good low-temperature impact toughness and a preparation method thereof. Background technique [0002] Wear-resistant steel is a wear-resistant material widely used in various wear conditions. With the advancement of production technology, new types of wear-resistant steel emerge in endlessly. The smelting, casting, heat treatment and machining processes are continuously improved. Wear-resistant steel Its comprehensive mechanical properties, wear resistance and service life are gradually improving, and its application fields are expanding day by day. Commonly made engineering machinery, mining machinery, coal mining machinery, crusher and other mechanical parts are widely used in various departments such as metallurgy, mining, building materials, electric power, railways and military, such as bulldozers, loaders, excavators,...

AI Technical Summary

Problems solved by technology

[0005] Chinese Patent Publication No. CN 101775545 A Baoshan Iron and Steel Co., Ltd. applied for "a low-alloy high-strength high-toughness wear-resistant steel plate and its manufacturing method". The cost of adding 0.01-0.04% Nb to the steel is higher than that of the present invention. The room temperature impact energy is greater than 80J, but it does not have the effect of -40℃ low temperature impact energy at 50J

[0006] The Chinese patent publication number is CN 101638755 A "high toughness and ultra-high strength wear-resistant steel plate" applied by Northeastern University. The Mn content of the steel is 1.0-1.6%. If the Mn content is high, the casting slab will easily form central segregation during the continuous casting process, which will seriously affect the product. The uniformity of performance will cause cracking quality gaps and reduce the welding performance of steel. At the same time, the product is smelted without LF refining, and the content of molten steel inclusions cannot be guaranteed, which will have a negative impact on the impact toughness of the product.

[0007] Chinese Patent Publication No. CN 101775539 A Baoshan Iron and Steel Co., Ltd. applied for "a high-toughness wear-resistant steel plate and its manufacturing method". The steel has a C content of 0.04-0.11wt%. The effect of hardenability is extremely obvious. It has a certain effect to improve the toughness of steel by reducing the carbon content, but it will directly lead to the decrease of hardenability of steel, and the uniformity of performance in the thickness direction cannot be guaranteed.

For wear-resistant steel, the hardenability is an important indicator to measure the service life of the product, and the hardenability is poor

[0008] Chinese Patent Publication No. CN 102666897 A "High Toughness and Wear-Resistant Steel and Its Manufacturing Method" applied by Sumitomo Metal Industries Co., Ltd. This invention adds 0.005 to 0.03% of Nb alloy elements, and the cost is relatively high

[0009] China Patent Publication No. CN 101880831 A "A high-strength, high-toughness, low-alloy wear-resistant steel and its manufacturing method" applied by Northeastern University and Nanjing Iron and Steel Co., Ltd. The Mn content of the invention steel is 1.2-1.6%, and the Mn content is as high as In the continuous casting process, the slab is very easy to form central segregation, which seriously affects the performance uniformity of the product. At the same time, it will cause cracking quality gaps and reduce the welding performance of the steel. Guaranteed, will have a negative impact on the impact toughness of the product

At the same time, the invention can only guarantee the impact toughness at -20°C above 60J, but cannot guarantee the impact toughness at -40°C

[0010] Chinese Patent Publication No. CN 102337455 A Inner Mongolia Baogang Ganglian Co., Ltd. applied for "a rare earth-treated high-toughness wear-resistant steel plate". The steel type of this invention can only guarantee the low-temperature impact energy of -20°C above 50J, but cannot guarantee the low-temperature impact energy of -40°C, that is, the wear-resistant steel required for the -40°C low-temperature impact required in the severe cold zone cannot be guaranteed on the basis of low-cost design

[0011] Chinese Patent Publication No. CN 102747282 A "A High Hardness and High Toughness Wear-Resistant Steel Plate and Its Manufacturing Method" applied by Baoshan Iron and Steel Co., Ltd. The content of C in the steel is 0.36-0.45wt%. Excellent welding performance, at the same time, the steel is added with 0.010-0.040% Nb, the cost is high