High-tensile-strength steel for needle valve body of ultrahigh-pressure common-rail fuel injection system of diesel engine

Abstract

The invention provides high-tensile-strength steel for a needle valve body of an ultrahigh-pressure common-rail fuel injection system of a diesel engine. The high-tensile-strength steel comprises, byweight, 0.2%-0.6% of C, 0.6%-1.3% of Si, 0.2%-0.8% of Mn, smaller than or equal to 0.05% of S, smaller than or equal to 0.025% of P, 4.0%-6.5% of Cr, 0.8%-1.3% of V, 0.30%-0.45% of Mo, 0.08%-0.12% ofTi, 0.005%-0.050% of N, and the balance Fe. The steel has high tensile strength and is suitable for hydraulic pressure exceeding 200 MPa in the ultrahigh-pressure needle valve body, and the needle valve does not have obvious plastic deformation under the hydraulic pressure condition. The steel is particularly suitable for producing steel for needle valve bodies.

Description

technical field [0001] The invention relates to the technical field of alloy steel, in particular to a high tensile strength steel for a needle valve body of an ultra-high pressure common rail fuel injection system of a diesel engine. Background technique [0002] Diesel engine common rail fuel injection technology has experienced three generations of development since it was invented in 1986, and has achieved rapid development in inventions such as electronic control, mechanical control, and material processing. At present, this technology has been successfully used in foreign countries with diesel engines as power It is widely used in automobiles, which is the inevitable trend of the world automobile industry to meet the increasingly stringent exhaust emission standards. my country started relatively late in this technology, and the cooperation in the entire industrial chain is poor. In recent years, large state-owned enterprises such as FAW have begun to increase investme...

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Problems solved by technology

This makes my country's diesel engine fuel injection system follow foreign technology from design to production and use, and there is no diesel engine production with completely independent intellectual property rights, which leads to my country's diesel engine technology being completely controlled by foreign countries, which is not conducive to my country's industry safety and national defense security.