CN102367554A

CN102367554A - High-performance quenched and tempered steel plate used in engineering machinery, and production technology thereof

Info

Publication number: CN102367554A
Application number: CN2011103374898A
Authority: CN
Inventors: 董瑞峰; 吴鹏飞; 温利军; 高志国; 李文艺; 丁晓志; 张军; 阎波; 孙丽钢; 黄楠; 黄利
Original assignee: Baotou Iron and Steel Group Co Ltd
Current assignee: Baotou Iron and Steel Group Co Ltd; Inner Mongolia Baotou Steel Union Co Ltd
Priority date: 2011-10-28
Filing date: 2011-10-28
Publication date: 2012-03-07

Abstract

The invention discloses a high-performance quenched and tempered steel plate used in engineering machinery, and a production technology thereof. The invention belongs to the technical field of material molding. The steel plate is characterized in that: a slab comprises chemical components of, by weight: 0.10-0.13% of C, 0.25-0.45% of Si, 1.4-1.8% of Mn, no more than 0.018% of P, no more than 0.005% of S, less than 0.035% of Alt, 0.150-0.30% of Cr, 0.030-0.055% of Nb, 0.040-0.080% of V, 0.008-0.025% of Ti, and balance of Fe and inevitable impurities. The rolling technology comprises conditions that: the heating temperature is 1200 to 1250 DEG C; a high-temperature section (heating and soaking) takes no less than 200min; a soaking time is no less than 30min; an initial rolling temperature is 1180 to 1230 DEG C; an initial finish rolling temperature is 890 to 40 DEG C; a finish rolling temperature is 830 to 890 DEG C; an Acc final cooling temperature is 550 to 650 DEG C; a cooling speed is 10 to 20 DEG C/s; a quenching temperature during a heat treatment is 900 to 950 DEG C; and a tempering temperature is 480 to 550 DEG C. The obtained steel plate has excellent mechanical properties. The tensile strength is no less than 820MPa, the yield strength is no less than 750MPa, the specific elongation is no less than 15%, and a longitudinal impact work under a temperature of -20 DEG C is larger than 170J. The production cost of the steel plate is low, and the welding performance of the steel plate is good. The production technology can be used in industrialized productions of steel plates with thicknesses of 10 to 30mm.

Description

A kind of engineering machinery is with high-performance hardened and tempered steel plate and production technique thereof

Technical field

Belong to the forming materials technical field, particularly hot-rolled steel plate and thermal treatment process.

Background technology

At present, engineering machinery adopts low-carbon and low-alloy composition System Design with hardened and tempered steel plate manufacturer great majority, obtains the high-strength hardened and tempered steel plate through controlled rolling, controlled chilling and thermal treatment.Related patent U.S. Patent No. such as Baoshan Iron & Steel Co., Ltd disclosed " 700MPa grade high strength and high toughness hardened and tempered steel plate and method of manufacture thereof cheaply " patent (number of patent application: 200810041043); Though can produce 700MPa high-strength hardened and tempered steel plate; But contain Mo in the alloying constituent, expensive element such as Cr.Baoshan Iron & Steel Co., Ltd's disclosed " extra-thick quenched and tempered steel plate and method of manufacture thereof that a kind of obdurability coupling is good " patent (number of patent application: 200810042124) for another example; Through obtaining ys >=500MPa, tensile strength >=610MPa ,-40 ℃ the steel plate of Charpy ballistic work >=47J after recrystallize controlled rolling+modifier treatment; But relate to Cu, Cr, Ni, Mo and Ti, V, B element in the alloy system, production cost is higher.

Summary of the invention

The objective of the invention is to disclose that a kind of cost is lower, the engineering machinery of excellent property is with hardened and tempered steel plate and production technique thereof, the chemical ingredients of its slab and content (weight percent) should meet: C 0.10-0.13%, Si 0.25-0.45%; Mn 1.4-1.8%, P≤0.018%, S≤0.005%; Alt＜0.035%, Cr0.150-0.30%, Nb 0.030-0.055%; V 0.040-0.080%, Ti 0.008-0.025%, surplus is Fe and unavoidable impurities.

Rolling technology is: Heating temperature is 1200-1250 ℃, high temperature section (heating+soaking) >=200 minute, and soaking time is >=30 minutes, start rolling temperature is 1180-1230 ℃, 890-940 ℃ of finish rolling start rolling temperature, finishing temperature 830-890 ℃.550-650 ℃ of Acc final cooling temperature, speed of cooling 10-20 ℃/s.Quenching temperature is 900-950 ℃ during thermal treatment, and tempering temperature is 480-550 ℃.

The outstanding advantage of the present invention is that the TMCP+ modifier treatment can be produced thickness 10-30mm Plate Steel and had excellent mechanical property, tensile strength >=820MPa, and ys >=750MPa, unit elongation >=15%, the impact of collision merit is greater than 170J under-20 ℃ of conditions.Carbon equivalent is not more than 0.47%, and welding property is good, and production cost is low.

Embodiment

Below in conjunction with embodiment the present invention is done further description.

Embodiment 1:

Put into process furnace with intending rolling thickness for the 250mm slab, the slab tapping temperature is 1240 ℃, high temperature section (heating+soaking) >=200 minute, and soaking time is 30 minutes; (weight percent) chemical ingredients of slab is: C 0.12%, and Si 0.338%, and Mn 1.71%, and P 0.017%; S 0.002%, and Alt 0.027%, and Cr 0.227%, and Nb 0.046%; V 0.067%, and Ti 0.013%, and surplus is Fe and unavoidable impurities.Be rolled into the steel plate that thickness is 20mm, rolling and thermal treatment process is seen table 1, and its mechanical property is seen table 2.

Rolling and the thermal treatment process of table 1

The mechanical property of table 2 steel plate

Embodiment 2:

With intending rolling thickness is that the slab of 250mm is put into process furnace, and the slab tapping temperature is 1240 ℃, high temperature section (heating+soaking) >=200 minute, and soaking time is 30 minutes; Start rolling temperature is 1225 ℃, and (weight percent) chemical ingredients of slab is: C 0.111%, and Si 0.346%, and Mn 1.71%; P 0.018%, and S 0.002%, and Alt 0.027%, and Cr 0.235%; Nb 0.048%, and V 0.062%, and Ti 0.012%, and surplus is Fe and unavoidable impurities.Be rolled into the steel plate that thickness is 30mm, rolling and thermal treatment process is seen table 3, and its mechanical property is seen table 4.

Rolling and the thermal treatment process of table 3

The mechanical property of table 4 steel plate

Claims

1. an engineering machinery is used the high-performance hardened and tempered steel plate, it is characterized in that chemical composition content is by weight percentage: C 0.10-0.13%, Si 0.25-0.45%; Mn 1.4-1.8%, P≤0.018%, S≤0.005%; Alt＜0.035%, Cr 0.150-0.30%, Nb 0.030-0.055%; V 0.040-0.080%, Ti0.008-0.025%, surplus is Fe and unavoidable impurities.

2. an engineering machinery is with the rolling method of high-performance hardened and tempered steel plate; It is characterized in that said steel plate has the chemical ingredients of steel in the claim 1, rolling technology is following: Heating temperature is 1200-1250 ℃, high temperature section (heating+soaking) >=200 minute; Soaking time is >=30 minutes; Start rolling temperature is 1180-1230 ℃, 890-940 ℃ of finish rolling start rolling temperature, finishing temperature 830-890 ℃.550-650 ℃ of Acc final cooling temperature, speed of cooling 10-20 ℃/s.

3. an engineering machinery is characterized in that with high-performance hardened and tempered steel plate hardening and tempering process said steel plate has the chemical ingredients of steel in the claim 1, and modifier treatment technology is: quenching temperature 900-950 ℃, and tempering temperature 480-550 ℃.