CN102796957A

CN102796957A - Steel plate for high toughness 15CrMoR pressure container

Info

Publication number: CN102796957A
Application number: CN2012103162634A
Authority: CN
Inventors: 孙卫华; 邵正伟; 成小龙; 孙风晓; 刘晓东; 刘金泉; 郑淑胜; 朱延山
Original assignee: Jinan Iron and Steel Group Co Ltd
Current assignee: Jinan Iron and Steel Group Co Ltd
Priority date: 2012-08-31
Filing date: 2012-08-31
Publication date: 2012-11-28
Anticipated expiration: 2032-08-31
Also published as: CN102796957B

Abstract

The invention relates to the manufacturing field of steel for a chrome-molybdenum heat resistant pressure container, in particular to a steel plate for a high toughness 15CrMoR pressure container. The steel plate is prepared by the following components in percentage by mass: 0.14-0.18% of C (Carbon), 0.15-0.40% of Si (Silicon), 0.45-0.70% of Mn (Manganese), no more than 0.020% of P (Phosphorus), no more than 0.005% of S (Sulfur), 0.90-1.10% of Cr (Chromium), 0.45-0.60% of Mo (Molybdenum) and the balance of Fe (Ferrum) and inevitable impurities. The steel plate for the high toughness 15CrMoR pressure container, provided by the invention, has the advantages as follows: (1) as impact toughness of 15CrMoR is high, low temperature impact performance is that transverse impact is not less than 80 J at -40 DEG C and far higher than the nationally specified transverse impact; (2) pure steel quality and low content of harmful elements such as S and the like; (3) as refined grain elements, such as Nb, V, Ti and the like, are not added, cost is greatly saved; and (4) when a requirement on low temperature toughness is satisfied, good conventional properties and good high-temperature tensile properties are obtained.

Description

A kind of H.T. 15CrMoR steel heavy plate for pressure vessels

Technical field

The present invention relates to chromium-molybdenum is that heat-resisting steels for pressure vessel use is made the field, specifically is meant a kind of H.T. 15CrMoR steel heavy plate for pressure vessels.

Background technology

The 15CrMoR steel is that a petrochemical equipment middle temperature and pressure force container commonly used is used steel grade; Because work under higher temperature and pressure; Therefore its service condition is abominable, requires material will have higher heat resistance, good toughness plasticity, erosion resistance and welding property.

Though 15CrMoR high temperature steel pressurized vessel great majority are at high temperature to work; But after pressurized vessel and pipeline manufacturing completion, will at normal temperatures even possibly under extreme climate, carry out the water test of pressure 1.25 multiplication of voltage power; And after installation has been overhauled; Also will experience the water test and cold start-up process, therefore, this steel grade also will have certain anti-brittle failure property on the basis that guarantees its fundamental property.In addition; The container that this steel grade is made is operation at high temperature for a long time, does not have during parking to prevent the too fast measure of lowering the temperature reliably, causes thermal fatigue and temperature stress big; So when this steel grade of design, also will consider its toughness deposit, the ability of its resistance to deformation and temperature variation is strengthened.Conventional 15CrMoR container steel is according to stipulating among the GB713-2008 that impelling strength requires to reach 20 ℃ of transverse impact >=31J and gets final product, and far can not satisfy certain user's particular requirement, makes the application of this steel grade receive certain restriction.

Summary of the invention

The object of the present invention is to provide a kind of H.T. 15CrMoR steel heavy plate for pressure vessels.

The present invention realizes through following technical scheme:

A kind of H.T. 15CrMoR steel heavy plate for pressure vessels is prepared from following component by mass percent: C:0.14～0.18%, Si:0.15～0.40%; Mn:0.45～0.70%; P≤0.020%, S≤0.005%, Cr:0.90～1.10%; Mo:0.45～0.60%, other are Fe and unavoidable impurities.

Above-mentioned steel plate thickness is 10～80mm, and the steel plate thickness of optimization is 20～60mm.

Above-mentioned H.T. 15CrMoR steel heavy plate for pressure vessels, they are transverse impact >=80J in the time of-40 ℃.

The preparation method of above-mentioned a kind of H.T. 15CrMoR steel heavy plate for pressure vessels, its concrete steps are:

1) smelt: raw material is reduced to below 0.003% the massfraction of sulphur through molten iron KR pretreatment desulfurizing, through the 120t top and bottom combined blown converter smelting; Send into the refining of LF refining furnace behind the ladle argon-blown again, carry out trimming, desulfurization makes massfraction≤0.005% of sulphur again, and temperature control to 1600～1650 ℃; In the VD stove, carry out vacuum outgas then and handle, reduce oxygen, nitrogen and hydrogen content, make [O]≤30PPM, [N]≤40PPM; [H]≤2PPM, and further even composition, the empty time of fidelity was not less than 15 minutes; Processing utilizes feeding wire machine to feed calcium iron wire 2m/t fast with 180～210m/min speed after finishing; After the line feeding molten steel is carried out stirring a little less than the soft blow argon, the soft blow argon time was not less than 10 minutes, argon gas stream 80～150L/min; Molten steel smelting component after the processing guarantees P≤0.020%, S≤0.005%.

2) casting: go up 270mm * 2100mm section slab caster cast behind the VD stove vacuum breaker, casting machine adopts fan-shaped section induction stirring and strand gently to depress technology in the casting process, and the stacking slow cooling time was not less than 48 hours after continuously cast bloom rolled off the production line;

3) heating: strand is at stove coefficient heat-up time 0.9～1.1min/mm; 1140～1200 ℃ of the tapping temperatures of steel billet;

4) rolling: in the operation of rolling, rolling employing is thick, finish rolling is rolling stage by stage, roughing mill start rolling temperature >=1100 ℃; Adopt low speed to depress rolling technology greatly, the intermediate blank thickness of assurance [10,50] mm specification is not less than 2.5 times of finished product thickness; (50; 80] the intermediate blank thickness of mm specification is not less than 2 times of finished product thickness, and the steel plate finish rolling below the thickness 12mm is temperature control not, 12mm with upper steel plate finish rolling start rolling temperature by 900～980 ℃ of controls; Finishing temperature is by 840～920 ℃ of controls, air cooling behind the steel plate rolling;

5) thermal treatment: the normalizing treatment temperature is 890～930 ℃, in-furnace time 1.4～1.8min/mm and the minimum 30min that is not less than; 600～700 ℃ of temper temperature, in-furnace time 2.0～3.0min/mm and the minimum 60min that is not less than, steel plate come out of the stove the back air cooling to room temperature, and this moment, steel plate thickness was 10～80mm.

H.T. 15CrMoR steel heavy plate for pressure vessels of the present invention through pure steel, optimization temperature-controlled rolling and thermal treatment process, obtains ideal perlite+ferritic structure; Its uniform crystal particles is tiny; On the basis of normal temperature stretching, high temperature tensile properties conformance with standard GB713-2008, improved its impelling strength greatly ,-40 ℃ of transverse impact merit >=80J; Impact test temperature is lower than 20 ℃ of GB regulation and reaches 60 ℃; And ballistic work reaches as high as 137J, can reach 3～4 times of GB prescribed value, has satisfied the processing and manufacturing of user under particular surroundings and the toughness reserve requirements aspect the use.

The present invention has the following advantages: (1) 15CrMoR impelling strength is high, and low temperature impact properties reaches-40 ℃ of transverse impact >=80J, stipulates far above GB.(2) steel of the present invention is pure, and harmful element content such as S are low; (3) do not add crystal grain thinning elements such as Nb, V, Ti, practiced thrift cost greatly; (4) under the requirement of satisfying low-temperature flexibility, traditional performance and high temperature tensile properties are good;

Embodiment

Further specify the present invention through following specific embodiment:

Embodiment one

The H.T. 15CrMoR steel heavy plate for pressure vessels of present embodiment is to be prepared from following component by mass percent: C:0.18%, Si:0.23%, Mn:0.55%; P:0.016%, S:0.002%, Cr:1.03%; Mo:0.46%, surplus is Fe and unavoidable impurities;

The preparation method of the H.T. 15CrMoR steel heavy plate for pressure vessels of present embodiment is following:

1) smelts: after the raw material molten iron KR pre-treatment,, send into the refining of LF refining furnace behind the ladle argon-blown again through top and bottom combined blown converter smelting; In the VD stove, carry out vacuum-treat then; The empty 17 minutes time of fidelity, processing finishes back feeding calcium iron wire 2m/t, and the soft blow argon is 10 minutes after the line feeding;

2) casting: go up the continuous caster cast behind the VD stove vacuum breaker, casting machine adopts fan-shaped section induction stirring and strand gently to depress technology in the casting process, and stacking slow cooling was 48 hours after continuously cast bloom rolled off the production line;

3) heating: strand time inside furnace 4 hours, 1150 ℃ of tapping temperatures;

4) rolling: employing is thick, finish rolling is rolling stage by stage, and rolling intermediate blank thickness is 100mm, 940 ℃ of finish rolling start rolling temperatures, and mill product steel plate specification is 36mm;

5) thermal treatment: the normalizing treatment temperature is 910 ℃, in-furnace time 55min; 650 ℃ of tempering temperatures, air cooling after in-furnace time 90min, steel plate come out of the stove.

Embodiment two

The H.T. 15CrMoR steel heavy plate for pressure vessels of present embodiment is to be prepared from following component by mass percent: C:0.17%, Si:0.25%, Mn:0.55%; P:0.012%, S:0.002%, Cr:1.03%; Mo:0.47%, surplus is Fe and unavoidable impurities.

The preparation method of the H.T. 15CrMoR steel heavy plate for pressure vessels of present embodiment is with embodiment one, and difference is that the empty time of VD stove fidelity is 15 minutes, and strand heat-up time in stove is 4.5 hours, 1180 ℃ of tapping temperatures.

Embodiment three

The H.T. 15CrMoR steel heavy plate for pressure vessels of present embodiment is to be prepared from following component by mass percent: C:0.17%, Si:0.27%, Mn:0.55%; P:0.017%, S:0.001%, Cr:0.94%; Mo:0.46%, surplus is Fe and unavoidable impurities.

The preparation method of the H.T. 15CrMoR steel heavy plate for pressure vessels of present embodiment is with embodiment one, and difference is that the empty time of VD stove fidelity is 15 minutes, and continuously cast bloom is 4.5 hours in process furnace heat-up time; 1180 ℃ of tapping temperatures, finishing mill start rolling temperature are 950 ℃, and mill product steel plate specification is 40mm; The normalizing treatment temperature is 920 ℃; In-furnace time is 60 minutes, and the temper temperature is 660 ℃, and in-furnace time is 100 minutes.

Embodiment four

The H.T. 15CrMoR steel heavy plate for pressure vessels of present embodiment is to be prepared from following component by mass percent: C:0.16%, Si:0.25%, Mn:0.53%; P:0.014%, S:0.001%, Cr:0.93%; Mo:0.46%, surplus is Fe and unavoidable impurities.

The preparation method of the H.T. 15CrMoR steel heavy plate for pressure vessels of present embodiment is with embodiment one, and difference is that the empty time of VD stove fidelity is 15 minutes, and continuously cast bloom is 4.5 hours in process furnace heat-up time; 1180 ℃ of tapping temperatures, rolling intermediate blank thickness is 130mm, the finishing mill start rolling temperature is 950 ℃; Mill product steel plate specification is 56mm, and the normalizing treatment temperature is 920 ℃, and in-furnace time is 85 minutes; The temper temperature is 660 ℃, and in-furnace time is 140 minutes.15CrMoR steel heavy plate for pressure vessels to preparation among the above embodiment one to four carries out Mechanics Performance Testing, like table 1,2, shown in 3.

Claims

1. a H.T. 15CrMoR steel heavy plate for pressure vessels is characterized in that: be prepared from following component by mass percent: C:0.14～0.18%, Si:0.15～0.40%; Mn:0.45～0.70%; P≤0.020%, S≤0.005%, Cr:0.90～1.10%; Mo:0.45～0.60%, other are Fe and unavoidable impurities.

2. a kind of H.T. 15CrMoR steel heavy plate for pressure vessels according to claim 1 is characterized in that: said steel plate thickness is 10～80mm.

3. a kind of H.T. 15CrMoR steel heavy plate for pressure vessels according to claim 2 is characterized in that: said steel plate thickness is 20～60mm.

4. H.T. 15CrMoR steel heavy plate for pressure vessels according to claim 1 is characterized in that: described H.T. 15CrMoR steel heavy plate for pressure vessels, they are transverse impact >=80J in the time of-40 ℃.

5. the preparation method of a kind of H.T. 15CrMoR steel heavy plate for pressure vessels according to claim 1, its concrete steps are:

Smelt: raw material is reduced to below 0.003% the massfraction of sulphur through molten iron KR pretreatment desulfurizing, through the 120t top and bottom combined blown converter smelting; Send into the refining of LF refining furnace behind the ladle argon-blown again, carry out trimming, desulfurization makes massfraction≤0.005% of sulphur again, and temperature control to 1600～1650 ℃; In the VD stove, carry out vacuum outgas then and handle, reduce oxygen, nitrogen and hydrogen content, make [O]≤30PPM, [N]≤40PPM; [H]≤2PPM, and further even composition, the empty time of fidelity was not less than 15 minutes; Processing utilizes feeding wire machine to feed calcium iron wire 2m/t fast with 180～210m/min speed after finishing; After the line feeding molten steel is carried out stirring a little less than the soft blow argon, the soft blow argon time was not less than 10 minutes, argon gas stream 80～150L/min; Molten steel smelting component after the processing guarantees P≤0.020%, S≤0.005%;

Casting: go up 270mm * 2100mm section slab caster cast behind the VD stove vacuum breaker, casting machine adopts fan-shaped section induction stirring and strand gently to depress technology in the casting process, and the stacking slow cooling time was not less than 48 hours after continuously cast bloom rolled off the production line;

Heating: strand is at stove coefficient heat-up time 0.9～1.1min/mm; 1140～1200 ℃ of the tapping temperatures of steel billet;

Rolling: in the operation of rolling, rolling employing is thick, finish rolling is rolling stage by stage, roughing mill start rolling temperature >=1100 ℃; Adopt low speed to depress rolling technology greatly, the intermediate blank thickness of assurance [10,50] mm specification is not less than 2.5 times of finished product thickness; (50; 80] the intermediate blank thickness of mm specification is not less than 2 times of finished product thickness, and the steel plate finish rolling below the thickness 12mm is temperature control not, 12mm with upper steel plate finish rolling start rolling temperature by 900～980 ℃ of controls; Finishing temperature is by 840～920 ℃ of controls, air cooling behind the steel plate rolling;

Thermal treatment: the normalizing treatment temperature is 890～930 ℃, in-furnace time 1.4～1.8min/mm and the minimum 30min that is not less than; 600～700 ℃ of temper temperature, in-furnace time 2.0～3.0min/mm and the minimum 60min that is not less than, steel plate come out of the stove the back air cooling to room temperature, and this moment, steel plate thickness was 10～80mm.