CN104745958A - Steel wire rod for furniture spring and production method of steel wire rod - Google Patents

Abstract

The invention relates to a steel wire rod for a furniture spring, which comprises the following main components in percentage by weight (wt%): 0.58-0.67 percent of C, 0.19-0.25 percent of Si, 0.60-0.68 percent of Mn and the balance of Fe. The steel wire rod further comprises the following residual components in percentage by weight (wt%): less than 0.027 percent of P, less than 0.012 percent of S, less than 0.04 percent of Cu, less than 0.03 percent of As, less than 0.028 percent of Sn, less than 0.03 percent of Ti, less than 0.005 percent of Nb, less than 0.0005 percent of B, less than 0.097 percent of Cr, less than 0.03 percent of Ni, less than 0.005 percent of V, less than 0.01 percent of Mo and less than 0.005 percent of Als. The steel wire rod has the characteristics of simple production process, low processing cost, excellent comprehensive performance and the like and can meet the requirement of wire rod raw materials of a mattress spring.

Description

A kind of furniture spring steel wire rod and production method thereof

Technical field

The invention belongs to non-alloyed steel and manufacturing process technology field, relate to one furniture spring steel wire rod and production method thereof.

Background technology

Along with the development of China's industrial economy and the raising of people's quality of life, spring becomes part the most frequently used in machinery industry and daily life, and production technique and the manufacture method of various spring steel wire rod are also arisen at the historic moment, such as:

Publication number is the production technique that the Chinese patent document of CN101716721A discloses a kind of spring steel wire rod, and this technology mainly comprises following operation: raw material preparation, EAF eccentric bottom tapping electric arc furnace smelting, LF external refining, VD Fruit storage, CCM continuous casting, continuously cast bloom ball blast, flaw detection, reconditioning, heating and high-speed rod-rolling mill are rolled into wire rod.Its furnace charge comprises following component by weight percentage: C: 0.35 ~ 0.42%, Mn:0.50-0.80%, P≤0.025%, S≤0.025%, Si:1.5-1.8%, Cr≤0.35%, Al≤0.050%, Cu≤0.20%, and surplus is Fe and inevitable impurity.

And for example publication number is that the Chinese patent document of CN102162068A discloses a kind of spring steel and manufacture thereof and heat treating method, the first refining of this spring steel preparation method is carried out in electric arc furnace, and smelting adopts silicon deoxidation, refining is ladle refining and low basicity slag vacuum (VD) refining techniques; Its Ingredient percent of spring steel wire rod that this technology is produced is: C 0.3 ~ 0.5%, Si 1.0 ~ 2.5%, Mn 0.3 ~ 1.5%, Cr 0.1 ~ 1.0%, Ni 0.01 ~ 0.3%, Cu≤0.15%, P≤0.010%, S≤0.010%, surplus is Fe and inevitable impurity.

Along with the raising of people's quality of life, spring mattress has come into huge numbers of families, it achieves the dream of different crowd healthiness sleep.As the bed net (spring) of whole mattress heart, demand also increases day by day, and the handling characteristics of mattress spring (mattress spring) is: section of steel wire is less, working temperature lower (≤120 DEG C).The handling characteristics of mattress spring determines its performance requriements: except playing except the necessary hardness of support mattress effect, also should have good rebound resilience.Mattress spring steel wire through suitable processing or thermal treatment, just need only can obtain very high tensile strength, enough toughness and good fatigue lifetime, just can meet the service requirements of mattress spring completely.

The principle of general spring selection is: first content with funtion requirement, is secondly requirement of strength, finally also should considers economy.And though the production of existing spring steel or preparation method can meet function and the requirement of strength of spring steel, be selected to mattress spring aspect against economy principle, because the production technology of existing spring steel obviously exists the higher weak point of following manufacturing cost:

(1) on Composition Design, silicon addition content is higher, it is the production technique of a kind of spring steel wire rod of CN101716721A as publication number, its Si content is up to 1.5-1.8%, publication number is a kind of spring steel of CN102162068A and manufacture thereof and heat treating method, its Si content also more than 1.0%, even up to 2.5%.The significantly increase of silicon addition content, not only wastes a large amount of Si alloy resources, also drastically increases steel product cost; And silicone content too high time can cause reducing the plasticity and toughness of steel, in the rolling and heat-processed of steel, easily there is decarburizing tendency, easily form inclusion, worsen the anti-fatigue performance of spring steel.

(2) all adopt the electric arc furnace smelting consuming more electric energy, and electric arc furnace smelting is obviously high than converter smelting cost, and refining all needs vacuum-treat, makes steel-making cost significantly increase.

(3) spring wire produced need carry out quench hot and average tempering thermal treatment, adds the high operating cost of downstream user to the investment of equipment for Heating Processing and heat treatment step.Spring wire as CN102162068A just needs quench hot (850 ~ 910 DEG C) and average tempering (400 ~ 620 DEG C), and these all need downstream user to increase the investment of equipment for Heating Processing and the sky high cost of heat treatment operation.

Summary of the invention

For overcoming above-mentioned technical disadvantages, the invention provides one furniture spring steel wire rod and production method thereof, itfor furniture spring steel wire rod raw material, have production technique simple, tooling cost is lower, spring steel wire rod high comprehensive performance, can meet the features such as the wire rod ingredient requirement of mattress spring.

The present invention solves the technological method that its technical problem adopts: a kind of furniture spring steel wire rod,comprise the principal constituent of following weight percent (wt%): C:0.58% to 0.67%, Si:0.19% to 0.25%, Mn:0.60% to 0.68%, Fe is surplus outside above-mentioned principal constituent and following residual components; Surplus comprises the residual components of following weight percent (wt%): P :≤0.027%, S :≤0.012%, Cu :≤0.04%, As≤0.03%, Sn≤0.028%, Ti≤0.03%, Nb≤0.005%, B≤0.0005%, Cr≤0.097%, Ni :≤0.03%, V≤0.005%, Mo≤0.01%, Als :≤0.005%.

Above-mentioned the preparation method of furniture spring steel wire rod, the steps include:

A, 120t converter smelting: according to the weight percent of above-mentioned principal constituent, converter terminal control overflow [C] >=0.08%, [P]≤0.15%, tapping is strict controls the lower quantity of slag, and tapping process adds 300kg bauxitic clay and 500kg lime carries out wash heat;

B, LF stove refining: plus silicon carbide or ferrosilicon powder carry out diffusive deoxidation in earlier stage, guarantee to make white slag fast; The mobility that refining process adds lime, bauxitic clay, fluorite (ball) adjust the quantity of slag and slag; Must terminate (power failure) front 10min in refining with carbon dust increasing C to complete, after refining, 10min can only adopt and feed the carburetting of C line; Forbid to feed the carburetting of C line again after Ca process; Refining terminates Ca process: middle bag first stove feeds calcium iron wire 200m/ stove or pure calcium line 120m/ stove, connects and waters stove hello calcium iron wire 120m/ stove or pure calcium line 80m/ stove; Soft argon blowing time >=12min after Ca process, obtained LF stove refined molten steel;

C, billet continuous casting: adopt LF stove refined molten steel, take strict molding casting; Metal in Tundish superheating temperature is 15 ~ 30 DEG C, and pulling rate is 1.7 ~ 1.8m/min; Adopt crystallizer and solidification end combination induction stirring (M+F-EMS); Continuous casting adopts M-EMS, frequency: 3Hz, electric current: 350A; Adopt end induction stirring, frequency: 8Hz, electric current: 350A; The weak cold mode of two cold employings; The obtained thick square billet of 170mm, then cooling in heap is not less than 24h;

D, strand heat: strand after cooling in heap is heated, heating zone control temperature 1000 ~ 1100 DEG C, soaking zone control temperature 1000 ~ 1100 DEG C, steel billet in process furnace heat-up time≤150min;

E, high line Danieli mill milling: temperature-controlled rolling is carried out to strand after heating, wherein, roughing temperature in 950 ~ 1040 DEG C, finish rolling BGV temperature in 890 ~ 920 DEG C, Dual module finished product unit TMB temperature in 860 ~ 880 DEG C, finished product speed control 95 ~ 105m/s, obtained finish rolling wire rod;

F, Stelmor air-cooled line is cold in line traffic control: carry out Stelmor air-cooled line to finish rolling wire rod cold in line traffic control, controlling laying temperature is 860 ~ 880 DEG C, Phase cooling target temperature 620 ~ 600 DEG C, before phase transformation, controlled cooling model speed is 10 ~ 18 DEG C/s, obtained described furniture spring steel wire rod after quality examination, inspection, wire rod finished diameter is 5.5mm and 6.5mm.

The invention has the beneficial effects as follows: on steel billet composition proportion basis of the present invention, only adopt the converter smelting of electric energy less energy intensive, without the need to RH vacuum refinement, by the online temperature-controlled rolling of high line and the combination of rolling rear forced air cooling, achieve and obtain elongation after fracture A >=20%, the furniture spring steel wire rod of relative reduction in area >=52%, it is made to possess the condition cancelling lead bath quenching operation before drawing completely, reduce process for processing cost, also can meet the requirement of furniture spring steel wire rod high comprehensive performance simultaneously, spring after cold-forming is also without the need to quench hot and average tempering operation, save expensive thermal treatment cost, there is production technique simple, tooling cost is lower, spring steel wire rod high comprehensive performance, the features such as the wire rod ingredient requirement of mattress spring can be met.

Embodiment

Below in conjunction with embodiment, the present invention is further described.

a kind of furniture spring steel wire rod,comprise the principal constituent of following weight percent (wt%): C:0.58% to 0.67%, Si:0.19% to 0.25%, Mn:0.60% to 0.68%, Fe is surplus outside above-mentioned principal constituent and following residual components; Surplus comprises the residual components of following weight percent (wt%): P :≤0.027%, S :≤0.012%, Cu :≤0.04%, As≤0.03%, Sn≤0.028%, Ti≤0.03%, Nb≤0.005%, B≤0.0005%, Cr≤0.097%, Ni :≤0.03%, V≤0.005%, Mo≤0.01%, Als :≤0.005%.

Above-mentioned the preparation method of furniture spring steel wire rod, the steps include:

A, 120t converter smelting: according to the weight percent of above-mentioned principal constituent, converter terminal control overflow [C] >=0.08%, [P]≤0.15%, tapping is strict controls the lower quantity of slag, and tapping process adds 300kg bauxitic clay and 500kg lime carries out wash heat;

B, LF stove refining: plus silicon carbide or ferrosilicon powder carry out diffusive deoxidation in earlier stage, guarantee to make white slag fast; The mobility that refining process adds lime, bauxitic clay, fluorite (ball) adjust the quantity of slag and slag; Must terminate (power failure) front 10min in refining with carbon dust increasing C to complete, after refining, 10min can only adopt and feed the carburetting of C line; Forbid to feed the carburetting of C line again after Ca process; Refining terminates Ca process: middle bag first stove feeds calcium iron wire 200m/ stove or pure calcium line 120m/ stove, connects and waters stove hello calcium iron wire 120m/ stove or pure calcium line 80m/ stove; Soft argon blowing time >=12min after Ca process, obtained LF stove refined molten steel;

C, billet continuous casting: adopt LF stove refined molten steel, take strict molding casting; Metal in Tundish superheating temperature is 15 ~ 30 DEG C, and pulling rate is 1.7 ~ 1.8m/min; Adopt crystallizer and solidification end combination induction stirring (M+F-EMS); Continuous casting adopts M-EMS, frequency: 3Hz, electric current: 350A; Adopt end induction stirring, frequency: 8Hz, electric current: 350A; The weak cold mode of two cold employings; The obtained thick square billet of 170mm, then cooling in heap is not less than 24h;

D, strand heat: strand after cooling in heap is heated, heating zone control temperature 1000 ~ 1100 DEG C, soaking zone control temperature 1000 ~ 1100 DEG C, steel billet in process furnace heat-up time≤150min;

E, high line Danieli mill milling: temperature-controlled rolling is carried out to strand after heating, wherein, roughing temperature in 950 ~ 1040 DEG C, finish rolling BGV temperature in 890 ~ 920 DEG C, Dual module finished product unit TMB temperature in 860 ~ 880 DEG C, finished product speed control 95 ~ 105m/s, obtained finish rolling wire rod;

F, Stelmor air-cooled line is cold in line traffic control: carry out Stelmor air-cooled line to finish rolling wire rod cold in line traffic control, controlling laying temperature is 860 ~ 880 DEG C, Phase cooling target temperature 620 ~ 600 DEG C, before phase transformation, controlled cooling model speed is 10 ~ 18 DEG C/s, obtained described furniture spring steel wire rod after quality examination, inspection, wire rod finished diameter is 5.5mm and 6.5mm.

In chemical composition ranges of the present invention, determine embodiment 1, 2, 3 chemical compositions (wt%) are as shown in table 1 below, wherein control Fe is 98.3 ~ 98.4%, Si is 0.19 ~ 0.25%, C is 0.58 ~ 0.67%, P≤0.027%, S≤0.012%, Cu≤0.04%, As≤0.03%, Sn≤0.028%, embodiment 1, 2, the smelting continuous casting step of 3 and controling parameters are as shown in table 2 below, embodiment 1, 2, the strand heating of 3, temperature-controlled rolling, cooling control after rolling step and technology characteristics parameter are as shown in table 3 below, the end properties of finally obtained furniture spring steel wire rod and spring wire thermal treatment are as shown in table 4 below.

Contrast 1 below in table 1,2,3,4 is the patent document of the production technique of a CN101716721A spring steel wire rod for publication number, below contrast 2 in table 1,2,3,4 disclose patent document in a kind of spring steel and manufacture thereof and heat treating method for Chinese patent document that publication number is CN102162068A.

Table 1 wire rod proportioning chemical composition (wt%)

Continuous casting system smelted by table 2

Table 3 temperature-controlled rolling and cooling control after rolling technology characteristics parameter

Table 4 wire rod end properties and spring wire thermal treatment

Item number	Embodiment 1	Embodiment 2	Embodiment 3	Contrast 1	Contrast 2
						Wire rod trimmed size (mm)	Φ6.5	Φ6.5	Φ5.5	—	—
Tensile strength Rm(MPa)	905	940	985	—	1290～1350
						Elongation after fracture A(%)	22	20	23	23	11～13.5
Relative reduction in area Z(%)	58	52	56	52	50～55
						Wire rod is the total decarburized layer degree of depth on one side	0.8%D	0	0.8%D	—	0.04～0.06mm
Steel wire quench hot (DEG C)	—	—	—	—	850～910
						Steel wire average tempering (DEG C)	—	—	—	—	400～620

Known by table 1, Si weight percent in embodiment 1 and example 2 is only: 0.19 ~ 0.25%, and contrast 1 and the Si of contrast 2 up to 1.0 ~ 2.5%, illustrate that spring steel Production method for wire rod of the present invention can save a large amount of Si alloy resources, save expensive Si cost of alloy; Known by table 2, embodiment 1 and example 2 only adopt the converter smelting of electric energy less energy intensive, without the need to VD or RH vacuum refinement process, and contrast 1 electric arc furnace smelting larger with the power consumption of contrast 2 employing electric energy, and adopt VD Fruit storage, illustrate that the steel-making cost of embodiment can significantly reduce; Spring after cold-forming, also without the need to quench hot and average tempering operation, saves expensive thermal treatment cost.

Known by table 4, the relative reduction in area Z of the furniture spring steel wire rod of the embodiment of the present invention 1 and embodiment 2 is not less than 52%, is not less than the relative reduction in area of contrast 1 and contrast 2; The elongation after fracture A of embodiment 1 and embodiment 2 is not less than 20%, and contrasts 1 with contrast 2 generally lower than 20%; Illustrate that the integrated performance index of embodiment 1 and embodiment 2 furniture spring steel wire rod all reaches excellent, the requirement of furniture spring steel wire rod can be met completely.Also known by table 4, the spring wire that embodiment 1 and embodiment 2 wire rod are produced does not need through quench hot and average tempering, save expensive thermal treatment cost, and contrast quench hot and 400 ~ 620 DEG C of average temperings that 2 need to heat-treat 850 ~ 910 DEG C of cost intensive.

In summary, implement the furniture spring steel wire rod that the present invention produces, production technique is simple, tooling cost is lower, can save downstream user thermal treatment cost, and its integrated performance index all reaches excellent, can meet the requirement of furniture spring steel wire rod completely.

Claims (2)

1. a kind of furniture spring steel wire rod, is characterized in that:comprise the principal constituent of following weight percent (wt%): C:0.58% to 0.67%, Si:0.19% to 0.25%, Mn:0.60% to 0.68%, Fe is surplus outside above-mentioned principal constituent and following residual components; Surplus comprises the residual components of following weight percent (wt%): P :≤0.027%, S :≤0.012%, Cu :≤0.04%, As≤0.03%, Sn≤0.028%, Ti≤0.03%, Nb≤0.005%, B≤0.0005%, Cr≤0.097%, Ni :≤0.03%, V≤0.005%, Mo≤0.01%, Als :≤0.005%.

2. as claimed in claim 1 the preparation method of furniture spring steel wire rod, is characterized in that step is:

A, 120t converter smelting: according to the weight percent of above-mentioned principal constituent, converter terminal control overflow [C] >=0.08%, [P]≤0.15%, tapping is strict controls the lower quantity of slag, and tapping process adds 300kg bauxitic clay and 500kg lime carries out wash heat;

B, LF stove refining: plus silicon carbide or ferrosilicon powder carry out diffusive deoxidation in earlier stage, guarantee to make white slag fast; The mobility that refining process adds lime, bauxitic clay, fluorite (ball) adjust the quantity of slag and slag; Must terminate (power failure) front 10min in refining with carbon dust increasing C to complete, after refining, 10min can only adopt and feed the carburetting of C line; Forbid to feed the carburetting of C line again after Ca process; Refining terminates Ca process: middle bag first stove feeds calcium iron wire 200m/ stove or pure calcium line 120m/ stove, connects and waters stove hello calcium iron wire 120m/ stove or pure calcium line 80m/ stove; Soft argon blowing time >=12min after Ca process, obtained LF stove refined molten steel;

C, billet continuous casting: adopt LF stove refined molten steel, take strict molding casting; Metal in Tundish superheating temperature is 15 ~ 30 DEG C, and pulling rate is 1.7 ~ 1.8m/min; Adopt crystallizer and solidification end combination induction stirring (M+F-EMS); Continuous casting adopts M-EMS, frequency: 3Hz, electric current: 350A; Adopt end induction stirring, frequency: 8Hz, electric current: 350A; The weak cold mode of two cold employings; The obtained thick square billet of 170mm, then cooling in heap is not less than 24h;

D, strand heat: strand after cooling in heap is heated, heating zone control temperature 1000 ~ 1100 DEG C, soaking zone control temperature 1000 ~ 1100 DEG C, steel billet in process furnace heat-up time≤150min;

E, high line Danieli mill milling: temperature-controlled rolling is carried out to strand after heating, wherein, roughing temperature in 950 ~ 1040 DEG C, finish rolling BGV temperature in 890 ~ 920 DEG C, Dual module finished product unit TMB temperature in 860 ~ 880 DEG C, finished product speed control 95 ~ 105m/s, obtained finish rolling wire rod;

F, Stelmor air-cooled line is cold in line traffic control: carry out Stelmor air-cooled line to finish rolling wire rod cold in line traffic control, controlling laying temperature is 860 ~ 880 DEG C, Phase cooling target temperature 620 ~ 600 DEG C, before phase transformation, controlled cooling model speed is 10 ~ 18 DEG C/s, obtained described furniture spring steel wire rod after quality examination, inspection, wire rod finished diameter is 5.5mm and 6.5mm.