A kind of hb400 crack-resistant high-strength martensitic wear-resistant steel and its production method

Abstract

The invention relates to HB 400 grade crack-resisting martensite wear-resistant steel with high strength. The steel comprises the following components in percentage: 0.045-0.078% of C, 0.20-0.50% of Si, 1.30-1.60% of Mn, less than or equal to 0.015% of P, less than or equal to 0.015% of S, 0.30-0.65% of Cr, 0.20-0.50% of Ni, 0.02-0.05% of Nb, 0.005-0.02% of Ti, 0.001-0.005% of B and 0.010-0.040% of Als. The production method comprises the production steps of: smelting and continuously casting to blanks; heating the cast blanks; rolling by sections; cooling; naturally cooling to room temperature; and annealing. The invention develops a non-tempering production process, so that the additive amounts of alloying elements which affect the crack resistance are reduced. A mixed structure of lath martensite, retained austenite and undissolved carbide is obtained, so that the wear resistance and the crack resistance of the alloy wear-resisting steel plate are improved. Compared with wear-resistant steel in same level at home and abroad, the additive amount of alloys is less, the cost of alloys is low, the manufacturing process is simple and the performances are excellent. Furthermore, the problem that martensite wear-resistant steel is easy to generate crack is solved, the subsequent manufacturing process is simple, and pre-heating is not required both for welding and flame cutting.

Description

technical field [0001] The invention belongs to the field of wear-resistant steel manufacturing for mechanical engineering, and in particular relates to an HB400 crack-resistant high-strength martensitic wear-resistant steel and a processing method thereof. Background technique [0002] Wear-resistant steel plates are widely used in mechanical products such as engineering, mining, construction, agriculture, cement production, ports, electric power and metallurgy that require high strength and high wear resistance due to extremely harsh working conditions. Such as bulldozers, loaders, excavators, dump trucks and various mining machinery, grab buckets, stackers and reclaimers, feeding bending structures, etc. A major problem that has plagued people in the industry for many years is wear and tear, especially structures that contact rocks, mineral materials, etc. that are subject to friction, impact, and erosion. According to statistics, in industrially developed countries, the...

AI Technical Summary

Problems solved by technology

Low-alloy martensitic steel has high hardness and high dislocation lath martensite, which can better resist crack propagation during wear. Compared with austenitic high-manganese steel, under moderate impact wear conditions, the steel This type has obvious advantages, and the comprehensive mechanical properties are also good, but the disadvantage is that it mainly relies on the hardness of the martensitic matrix to resist wear, and it also has high requirements for chemical composition control and heat treatment process.

[0005] CN102605234A provides a 400HB grade wear-resistant steel plate and its manufacturing method. The composition weight percentage is: C: 0.08~0.24%, Si: 0.1~0.3%, Mn: 0.7~1.7%, Cr: 1.0%, Mo: 0.6% %, B: 0.0005~0.004%, Ti: 0.005~0.04%, and the rest are Fe and trace impurity elements. It is produced by casting-controlled rolling-quenching and tempering heat treatment process. It has excellent performance and is suitable for easy-wearing equipment in manufacturing construction machinery. The advantage is that the C content in the composition is relatively high, which has an impact on the crack resistance, and the traditional casting process leads to low production efficiency, and a quenching and tempering heat treatment process is required. The expensive element Cr is also relatively high, making the cost relatively high. High and long production cycle

[0006] CN102127705A provides a high-strength and high-hardness wear-resistant steel, the weight percentage of which is: C: 0.2-0.3%, Si: 0.5-1.0%, Mn: 1.4-2.0%, Nb: 0.02-0.04%, Ti: 0.02 ~0.035%, Mo: 0.3~0.5%, V: 0.03~0.06%, B: 0.0015~0.02%, Al≤0.03%, N: 0.002~0.004%, online heat treatment + tempering process, online quenching final cooling temperature Less than 200°C, the disadvantage is that the C content in the composition is relatively high, which will cause flaky martensite structure in the metallographic structure, which has a great impact on the crack resistance; quenching treatment is required in the process, resulting in long production cycle and energy consumption. consumes a lot

[0007] CN102605272A provides a low-alloy ultra-high-strength wear-resistant steel and its production method. The ingot is obtained by die casting, and its composition weight percentage is: C: 0.20~0.35%, Si: 0.3~0.7%, Mn: 0.6~ 1.0%, Cr: 0.7~1.1%, Ni: 0.6~1.0%, Mo: 0.3~0.7%, and the rest are Fe and trace impurity elements. The ingot is forged and then normalized at 900°C~940°C (insulation Time 1~3 hours) -880°C~920°C quenching (holding time 1~3 hours) -150°C~220°C low temperature tempering (holding time 2~4 hours) to obtain high strength, high toughness, high The disadvantages of wear-resistant steel plates are: not only the relatively high C content in the composition, but also the flaky martensite structure in the metallographic structure, which has a great impact on the crack resistance; quenching treatment is required in the process, resulting in production The cycle is long, the energy consumption is large, and the addition of precious alloys Ni, Cr, and Mo is large, and the cost of the alloy is still high

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