CN103774051A

CN103774051A - High-strength steel

Info

Publication number: CN103774051A
Application number: CN201210412453.6A
Authority: CN
Inventors: 吴雪
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-10-25
Filing date: 2012-10-25
Publication date: 2014-05-07

Abstract

The invention discloses a high-strength steel which comprises the chemical ingredients in percentage by weight: 0.06-0.09% of C, 0.15-0.20% of Si, 1.30-1.50% of Mn, less than or equal to 0.010% of P, less than equal to 0.005% of S, 0.011-0.012% of Ti, 0.10-0.20% of Cr, 0.15-0.16% of Ni, 0.20-0.25% of Cu, 0.025-0.030% of Al, and the balance of Fe and inevitable impurities. The high-strength steel adopts a controlled rolling and controlled cooling process to obtain a bainite structure. Due to the heating processing technique, an ultrafine crystal structure is acquired, so that the material has the characteristics of low yield ratio, superplasticity, high strength and the like.

Description

A kind of high-strength steel

Technical field

The present invention relates to a kind of high-strength steel, specifically a kind of high-ductility high-strength steel.

Background technology

Along with society and expanding economy, Iron And Steel Industry is faced with three large pressure of saving resource, save energy, protection of the environment.Therefore, improve steel product quality, reduce costs, increase substantially its comprehensive mechanical property, become the main direction of ferrous materials research.

Conventionally, the yield strength of steel and tensile strength are directly proportional to-1/2 power of crystal grain diameter d, and grain refining significantly improves the yield strength and the tensile strength that make steel.The rising of yield tensile ratio significantly declines the cold forming capability that causes steel.Thereby, high-yield-ratio, inductile be existing Ultra-fine Grained production technology still need solve a difficult problem.

Summary of the invention

The object of this invention is to provide a kind of high-strength steel.By the micro-alloy low-carbon steel of this art breading, there is low yield strength ratio, high-ductility, high-intensity characteristic.

A kind of high-strength steel, it is characterized in that: in this steel, chemical composition is by weight percentage: C:0.06～0.09%, Si:0.15～0.20%, Mn:1.30～1.50%, P :≤0.010%, S :≤0.005%, Ti:0.011～0.012%, Cr:0.10～0.20%, Ni:0.15～0.16%, Cu:0.20～0.25%, Al:0.025～0.030%, surplus is Fe and inevitable impurity.

In the present invention, the alloying elements such as Cr, Ni, Cu mainly play strengthening effect.

The present invention improves yield strength and the tensile strength of steel plate by microalloying and controlled rolling and controlled cooling, by two-phase region quench or tempering increase precipitate separate out probability, obtain uniform ultra-fine grained ferrite structure, make material there is the characteristics such as low yield strength ratio, superplasticity, high strength.Stable processing technique, workable, cost is low, the material excellent combination property of acquisition.

Embodiment

Embodiment 1

A kind of high-strength steel, in this steel, chemical composition is by weight percentage: C:0.07%, Si:0.18%, Mn:1.30%, P:0.010%, S:0.005%, Ti:0.011%, Cr:0.10%, Ni:0.15%, Cu:0.20%, Al:0.025%, surplus is Fe and inevitable impurity.

The rolling technology of high-strength steel: adopt a cooling controlling and rolling controlling process, rolling front continuous blank heating temperature is 1180 ℃～1200 ℃; Adopt austenite recrystallization district and the two-stage control rolling of austenite non-recrystallization district, every time draft 10～15% of roughing, 1000～1050 ℃ of roughing finishing temperatures, roughing becomes the intermediate blank of 1.6 ~ 2.0 times of finished product thicknesses; Finish rolling start rolling temperature is 850～870 ℃, and every time draft is 10～15%, 800～830 ℃ of finish rolling finishing temperatures; Roll rear employing laminar flow cooling, 550～630 ℃ of final cooling temperatures, 7～10 ℃/s of rate of cooling, air cooling subsequently; Carrying out TMCP in hot rolling workshop, to be rolled into 21mm thick, obtains bainite structure.

Embodiment 2

A kind of high-strength steel, it is characterized in that: in this steel, chemical composition is by weight percentage: C:0.09%, Si:0.20%, Mn:1.50%, P:0.010%, S:0.005%, Ti:0.012%, Cr:0.20%, Ni:0.16%, Cu:0.25%, Al:0.030%, surplus is Fe and inevitable impurity.

Rolling technology is with embodiment 1.

In the present invention, the mechanical property of embodiment 1 and 2 is in table 1:

Table 1

The present invention improves yield strength and the tensile strength of steel plate by microalloying and controlled rolling and controlled cooling, by two-phase region quench increase precipitate separate out probability, obtain uniform ultra-fine grained ferrite structure, make material there is the characteristics such as low yield strength ratio, superplasticity, high strength.Stable processing technique, workable, cost is low, the material excellent combination property of acquisition.

Claims

1. a high-strength steel, it is characterized in that: in this steel, chemical composition is by weight percentage: C:0.06～0.09%, Si:0.15～0.20%, Mn:1.30～1.50%, P :≤0.010%, S :≤0.005%, Ti:0.011～0.012%, Cr:0.10～0.20%, Ni:0.15～0.16%, Cu:0.20～0.25%, Al:0.025～0.030%, surplus is Fe and inevitable impurity.