CN101215677B - Resource-saving high-nitrogen super diphase stainless steel alloy material and preparation method thereof - Google Patents

Abstract

The invention relates to a resource-saving high nitrogen super dual phase stainless steel alloy material with rare earth metal and a method for preparation. The compositions and the mass percentage of the alloy material are that carbon is bigger than 0 and is equal or less than 0.04 percent, sulfur is bigger than 0 and is equal or less than 0.01 percent, silicon is bigger than 0 and is equal or less than 1.0 percent, phosphorus is bigger than 0 and is equal or less than 0.015 percent, chromium is 24.0-26.0 percent, manganese is 9.0-11.0 percent, nitrogen is 1.0-3.0 percent, nitrogen is 0.45-0.55 percent, boron is 0.001-0.01 percent, rare earth cerium or yttrium is 0.005-0.20 percent, and other portion is ferric. Compared with the prior art, steel in the composition range of the resource-saving high nitrogen super dual phase stainless steel alloy material of the invention are all dual-phase regions in 1000-1300 DEG C, the austenite content changes between about 40 percent to 60 percent, tensile fracture strength is between 850 MPa to 950 MPa in room temperature, the yield strength is 650-750 MPa, and the fracture elongation is 25-50 percent.

Description

Resource-saving high-nitrogen super diphase stainless steel alloy material and preparation method thereof

Technical field

The present invention relates to a class and contain resource-saving high-nitrogen super diphase stainless steel alloy material of rare earth metal and preparation method thereof.

Background technology

Duplex stainless steel is made up of austenite and ferrite.The main component of duplex stainless steel is chromium, nickel, molybdenum, and wherein nickel is the most expensive; In order to reduce cost, reduce the content of nickel in the steel, can adopt the content that increases manganese and nitrogen.The reduction of nickel content can reduce the influence of prices of raw and semifnished materials fluctuation to stainless steel market.Therefore, along with the development of AOD, VOD refinery practice, especially can control the adding of nitrogen in the AOD stove, thereby promote the exploitation of nitrogen bearing duplex stainless steel, as its nitrogen content of 2205 steel about 0.15%.The adding of nitrogen has not only improved the anti-local corrosion performance of steel, and has solved stainless Welding Problems, makes duplex stainless steel become a kind of welding structured material, has expanded the range of application of duplex stainless steel greatly.Molybdenum element and constituent content height in the dual phase steel, thereby have good anti-local corrosion ability, this has just determined dual phase steel to have good application prospects in industries such as some special industrial circles such as petrochemical complex, papermaking, chemical fertilizer, shipbuilding.Because dual phase steel doubles than austenitic steel intensity, use the dual phase steel can weight reduction; Some developed countries have used dual phase steel as bridge structure and coastland building muscle at present.Along with the reduction with cost of further developing of metallurgical technology, also can accurately control the add-on of nitrogen, thereby new low nickel high-nitrogen super duplex stainless steel occur, as the UNS32750 steel, its nitrogen content is 0.25～0.35%, and nickel content is about 6～8%.

Summary of the invention

One of purpose of the present invention is to provide the resource-saving high-nitrogen super diphase stainless steel alloy material that a class is low-cost and have fine erosion resistance and hot workability.

Two of purpose of the present invention is to provide the preparation method of such alloy material.

For achieving the above object, mechanism of the present invention is as follows: can replace nickel and the rare earth action principle in steel according to nitrogen and manganese, a large amount of experimental studies development can be stablized austenite in the super dual phase steel with proper amount of cheap nitrogen and manganese, thereby reduce the consumption of valuable nickel; Simultaneously, the adding of B can reduce oxygen level, the adding of calcium can reduce sulphur content, after in this double phase stainless steel alloy, adding Rare-Earth Ce or Y more in addition, oxygen in the alloy and sulphur content reduce or form dystectic rare-earth oxide sulfate and sulfide disperse greatly in matrix, avoid low melting point sulfide to be present on the phase boundary, thereby improved the high temperature thermoplasticity of steel effectively.

According to above-mentioned mechanism, the present invention adopts following technical scheme:

A kind of resource-saving high-nitrogen super diphase stainless steel alloy material is characterized in that composition and mass percent thereof that this alloy material comprises are: (1) 0＜C≤0.04%, 0＜S≤0.01%, 0＜Si≤1.0%, 0＜P≤0.015%, Cr:24.0～26.0%, Mn:9.0～11.0%, Mo:2.0～4.0, Ni:1.0～3.0, N:0.45～0.55%, B:0.001～0.01%, Rare-Earth Ce or Y:0.005～0.20%, rest part are iron.

Above-mentioned alloy material also contains at least a among W, the Cu by percentage to the quality, and its content is 0.1～2.5% W, 0.1～2.5% Cu.

The preparation method of above-mentioned resource-saving high-nitrogen super diphase stainless steel alloy material is characterized in that the concrete steps of this method are:

A) adopt tradition conventional melting technology and pure iron seal of tube rare earth intermediate alloy throw-in play, iron and rare earth metal Ce or Y are made master alloy, it consists of: the quality percentage composition of Ce is 23.5% in the Fe-Ce master alloy; The quality percentage composition of Y is 15% in the Fe-Y master alloy;

B) according to above-mentioned ratio, with master alloy and remaining each composition of step a) preparation, after comprehensive batching was founded, casting finally made resource-conserving high nitrogen and low nickel super-duplex stainless steel alloy materials.

Compared with prior art, resource-conserving high nitrogen and low nickel super-duplex stainless steel alloy materials of the present invention, steel in this alloy material composition range is the two-phase region 1000～1300 ℃ of scopes, austenite content changes about 40～60%, the tensile break strength of room temperature is in 850～950Mpa scope, yield strength is in 650～750Mpa scope, and tension set is in 25～50% scopes.

Embodiment

Embodiment one: in the present embodiment, adopt the composition and the mass percent of duplex stainless steel as follows:

Cr 25.4％

Mo 3.2％

Ni 2.0％

N 0.50％

C 0.026％

Rare-Earth Ce 0.03%

Si 0.8％

Mn 10.0％

S 0.008％

P 0.01％

B 0.002％

The Fe surplus

Adopt the conventional smelting process of tradition, when feeding intake, adopt pure iron seal of tube master alloy throw-in play, i.e. the good master alloy of prepared beforehand.The alloy that consists of Fe and Ce of master alloy, the quality percentage composition of Ce is 23.5% in the Fe-Ce master alloy.Calculate and after batching founded, casting finally made the high-nitrogen, high-chromium, low-nickle super-duplex stainless steel alloy materials through comprehensive metering, its pitting drag equivalent value is 43.96.As cast condition is through forge hot, hot rolling, 1050 ℃ of solution treatment afterwards, and its room temperature tensile breaking tenacity is greater than 870MPa, and yield strength is greater than 650MPa, and tension set is greater than 32%.

Embodiment two: in the present embodiment, adopt the composition and the mass percent of duplex stainless steel as follows:

Cr 24.5％

Mo 2.9％

Ni 2.30％

N 0.48％

C 0.028％

Rare Earth Y 0.06%

Si 0.6％

Mn 9.8％

S 0.006％

P 0.015％

B 0.003％

Cu 0.8％

The Fe surplus

Adopt the conventional smelting process of tradition, when feeding intake, adopt pure iron seal of tube master alloy throw-in play.It is the good master alloy of prepared beforehand.The alloy that consists of Fe and Ce of master alloy, the quality percentage composition of Ce is 23.5% in the Fe-Ce master alloy.Calculate and after batching founded, casting finally made the high nitrogen and low nickel duplex stainless steel alloy material through comprehensive metering, its pitting drag equivalent value is 41.75.As cast condition is through forge hot, hot rolling, 1050 ℃ of solution treatment afterwards, and its room temperature tensile breaking tenacity is greater than 900MPa, and yield strength is greater than 650MPa, and tension set is greater than 32%.

Embodiment three: in the present embodiment, adopt the composition and the mass percent of duplex stainless steel as follows:

Cr 25.5％

Mo 3.5％

Ni 2.5％

N 0.52％

C 0.032％

Rare-Earth Ce 0.04%

Si 0.6％

Mn 10.5％

S 0.006％

P 0.015％

B 0.002％

Cu 0.8％

W 1.5％

The Fe surplus

Adopt the conventional smelting process of tradition, when feeding intake, adopt pure iron seal of tube master alloy throw-in play.It is the good master alloy of prepared beforehand.The alloy that consists of Fe and Ce of master alloy, the quality percentage composition of Ce is 23.5% in the Fe-Ce master alloy.Calculate and after batching founded, casting finally made the high nitrogen and low nickel duplex stainless steel alloy material through comprehensive metering, its pitting drag equivalent value is 45.37.As cast condition is through forge hot, hot rolling, 1050 ℃ of solution treatment afterwards, and its room temperature tensile breaking tenacity is greater than 900MPa, and yield strength is greater than 700MPa, and tension set is greater than 33%.

The resistance to corrosion of such material and UNS32750 are roughly suitable, and mechanical property is better than UNS32750, are the optimal candidate materials of replacing UNS32750, can reduce material cost significantly.In addition, has hot workability preferably in 1000～1300 ℃ of this materials.

Claims (3)

1. a resource-conserving high nitrogen biphase stainless steel alloy material is characterized in that composition and mass percent thereof that this alloy material comprises are: (1) 0＜C≤0.04%, 0＜S≤0.01%, 0＜Si≤1.0%, 0＜P≤0.015%, Cr:24.0～26.0%, Mn:9.0～11.0%, Mo:2.0～4.0, Ni:1.0～3.0, N:0.45～0.55%, B:0.001～0.01%, Rare-Earth Ce or Y:0.005～0.20%, rest part are iron.

2. resource-conserving high nitrogen biphase stainless steel alloy material according to claim 1 is characterized in that this alloy material by percentage to the quality, also contains at least a among W, the Cu, and its content is 0.1～2.5% W, 0.1～2.5% Cu.

3. the preparation method of a resource-conserving high nitrogen biphase stainless steel alloy material according to claim 1 and 2 is characterized in that the concrete steps of this method are:

A) adopt tradition conventional melting technology and pure iron seal of tube rare earth intermediate alloy throw-in play, iron and rare earth metal Ce or Y are made master alloy, it consists of: the quality percentage composition of Ce is 23.5% in the Fe-Ce master alloy; The quality percentage composition of Y is 15% in the Fe-Y master alloy;

B) according to above-mentioned ratio, with master alloy and remaining each composition of step a) preparation, after comprehensive batching was founded, casting finally made resource-conserving high nitrogen and low nickel super-duplex stainless steel alloy materials.