Low-carbon multi-element micro-alloyed multipurpose high-strength and high-toughness structural steel

Abstract

The invention discloses low-carbon multi-element micro-alloyed multipurpose high-strength and high-toughness structural steel. The structural steel is characterized by being formed by smelting 0.22-0.31 part of carbon (C), 0.15-0.30 part of silicon (Si), 0.45-0.85 part of manganese (Mn), 1.10-1.40 parts of chromium (Cr), 0.45-0.75 part of molybdenum (Mo), nickel (Ni) smaller than or equal to 0.25 part, copper (Cu) smaller than or equal to 0.25 part, sulfur (S) smaller than or equal to 0.005 part, phosphorus (P) smaller than or equal to 0.015 part, 0.02-0.10 part of vanadium (V), titanium (Ti) smaller than or equal to 0. 01 part, 0.02-0.05 part of niobium (Nb), 0.001-0.003 part of boron (B) and the balance iron by weight. According to the low-carbon multi-element micro-alloyed multipurpose high-strength and high-toughness structural steel, the heat processing technology risk is small and the rejection rate is low; the heat processing performance is more reliable, and the heat processing cost is lower; clean and civilized production can be realized. The multi-element micro-alloyed multipurpose high-strength and high-toughness structural steel can serve as carburizing steel; the surfaces of parts can have enough abrasive resistance through quenching and high-temperature tempering after carburization, and base bodies have good toughness.

Description

technical field [0001] The invention relates to a low-carbon multi-element micro-alloyed multi-purpose high-strength and toughness structural steel, which belongs to the technical field of metal materials and heat treatment processes thereof. Background technique [0002] Drilling tools have the characteristics of large cross-section and large wall thickness. Under the background of deeper drilling depth and more complicated geological conditions, 40CrMnMo and 4145H, which are currently widely used with high hardenability, can no longer fully meet the demand. The disadvantage of 40CrMnMo and 4145H is that for thick-walled parts, there is still a risk of quenching cracking due to water quenching. To be limited; for solid large-section parts, the mechanical properties are unstable or the strength cannot meet the design requirements or the impact power is not up to the standard due to the limitation of hardenability and the influence of the comprehensive stress of the quenching...

AI Technical Summary

Problems solved by technology

[0002] Drilling tools have the characteristics of large cross-section and large wall thickness. Under the background of deeper drilling depth and more complex geological conditions, the widely used 40CrMnMo and 4145H with high hardenability can no longer fully meet the demand

The disadvantage of 40CrMnMo and 4145H is that for thick-walled parts, there is still a risk of quenching cracks due to water quenching. When the wall thickness is large, especially when there are different sections and the wall thickness difference is large, the performance of the thick-walled part is often It must be limited; for solid large cross-section parts, often due to the limitation of hardenability and the influence of comprehensive stress in the quenching process, the mechanical properties are unstable or the strength cannot meet the design requirements or the impact energy is not up to standard, and even quenching cracks risks of

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