800MPa-grade high-strength steel for engineering machinery and production method of 800MPa-grade high-strength steel

Abstract

The invention discloses 800MPa-grade high-strength steel for engineering machinery and a production method thereof. The 800MPa-grade high-strength steel comprises the following chemical components in percentage by weight: 0.13 to 0.16 percent of C, 0.30 to 0.50 percent of Si, 0.80 to 1.60 percent of Mn, 0.20 to 0.70 percent of Cr, 0.10 to 0.30 percent of Mo, 0 to 0.50 percent of W, 0 to 0.30 percent of Ni, 0 to 0.40 percent of Cu, 0.010 to 0.030 percent of Nb, 0.010 to 0.030 percent of Ti, 0.010 to 0.050 percent of V, 0.0005 to 0.0030 percent of B, 0.02 to 0.06 percent of Al, 0.001 to 0.004 percent of Ca, 0.002 to 0.005 percent of N, less than or equal to 0.020 percent of P, less than or equal to 0.0050 percent of S, less than or equal to 0.0040 And the elements simultaneously meet the following relational expression: (Mo + 0.93 W + 0.52 Cr + 0.21 Mn + 0.55)/C is more than or equal to 6 and less than or equal to 10. According to the invention, the yield strength of the produced steel plate is greater than or equal to 800MPa, the tensile strength is greater than or equal to 850MPa, and the ductility is gt by component design and combined with controlled rolling, controlled cooling and rapid heat treatment processes; the impact energy at the temperature of-60 DEG C is greater than 100J.

Description

technical field [0001] The invention relates to the field of high-strength steel for engineering machinery, in particular to an 800MPa grade high-strength steel for engineering machinery and a production method thereof. Background technique [0002] 800MPa hot-rolled ultra-high-strength steel for construction machinery is mainly used in the manufacture of crane booms and pump truck booms and other components, which put forward high requirements for the strength, plasticity, low-temperature toughness and fatigue performance of the steel plate. Quenching and tempering heat-treated ultra-high-strength steel produced by traditional hot rolling and medium-heavy plate production lines takes a long time for quenching and tempering. For example, a 10mm steel plate is quenched for 30-50 minutes and tempered for 40-60 minutes. The production cycle of sheet steel needs more than one hour. This results in high energy costs and low production efficiency. In terms of performance, heatin...

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Problems solved by technology

[0007]The existing rapid heat treatment technology mainly focuses on the research of heat treatment methods, and there are relativ

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