CN105842308A - Method for eliminating super 304H steel inter-granular corrosion sensitivity - Google Patents
Method for eliminating super 304H steel inter-granular corrosion sensitivity Download PDFInfo
- Publication number
- CN105842308A CN105842308A CN201610178397.2A CN201610178397A CN105842308A CN 105842308 A CN105842308 A CN 105842308A CN 201610178397 A CN201610178397 A CN 201610178397A CN 105842308 A CN105842308 A CN 105842308A
- Authority
- CN
- China
- Prior art keywords
- sample
- shot
- peening
- super304h
- steel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D7/00—Modifying the physical properties of iron or steel by deformation
- C21D7/02—Modifying the physical properties of iron or steel by deformation by cold working
- C21D7/04—Modifying the physical properties of iron or steel by deformation by cold working of the surface
- C21D7/06—Modifying the physical properties of iron or steel by deformation by cold working of the surface by shot-peening or the like
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/44—Sample treatment involving radiation, e.g. heat
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/22—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material
- G01N23/225—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by measuring secondary emission from the material using electron or ion
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
- G01N2001/2866—Grinding or homogeneising
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
- G01N2001/2873—Cutting or cleaving
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Physics & Mathematics (AREA)
- Pathology (AREA)
- Immunology (AREA)
- General Physics & Mathematics (AREA)
- General Health & Medical Sciences (AREA)
- Biochemistry (AREA)
- Analytical Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Metallurgy (AREA)
- Electrochemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Molecular Biology (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Crystallography & Structural Chemistry (AREA)
- Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)
- Investigating And Analyzing Materials By Characteristic Methods (AREA)
Abstract
The invention discloses a method for eliminating super 304H steel inter-granular corrosion sensitivity, which includes the following steps: (1) preparation of a solid solution sample: performing homogenization solid solution treatment to a super 304H steel pipe to obtain the solid solution sample having homogeneous tissue, and cutting a flat sheet sample, and grinding the surface of the sample until the surface is flat and smooth to obtain a pre-treated sample for shot blasting treatment; (2) preparation of a shot blasting sample: setting certain shot blasting process parameters, performing surface shot blasting to the solid solution sample with the surface being ground to form a plastic deformation layer, which has certain thickness and hardness, on the surface of the solid solution sample, thereby forming a shot-blasting sample; and (3) desensitization thermal treatment: performing desensitization treatment to the shot-blasting sample at certain temperature for certain time to finally obtain the super 304H steel desensitized sample which is insensitive to inter-granular corrosion. The method is almost free of limitation on shape and size of the sample, is convenient to operate and is low in cost, has high industrial application value, and can quickly and effectively eliminate the inter-granular corrosion sensitivity of the super 304H steel without scarification on high-temperature strength of the material.
Description
Technical field
The present invention relates to one and process+desensitize heat treatment to eliminate the corruption of Super304H steel intergranular through shot blasting on surface
The novel method of erosion sensitivity, belongs to ultra supercritical coal-fired unit New-type boiler heat-resistance stainless steel field.
Background technology
Thermal power generation accounting in China's secondary energy sources, more than 80%, brings huge problem of environmental pollution.
China " 12 " plan proposes energy-saving and emission-reduction key project, for reducing coal consumption, improving efficiency, minimizing ring
Environment pollution, the advanced efficient ultra supercritical coal-fired unit of development has become the certainty of thermal power generating technology development
Trend.In recent years, ultra supercritical coal-fired unit development is swift and violent, mainly has benefited from novel high-strength heat resisting steel
Development and application.
The heat-resisting austenitic stainless steel of Super304H of SUMITOMO CHEMICAL metal company exploitation is (hereinafter referred to as
Super304H steel) it is on the basis of ASME SA-213 TP304H, improve C content, and add
About 3%Cu, 0.45%Nb and trace N, is developed by the solid solution and dispersion-strengthened action playing each element
The novel high-strength heat resisting steel possessing higher elevated temperature strength, high-temp plastic and high temperature oxidation resistance come.
China installs and in the extra-supercritical unit that puts into operation in a large number in recent years, superheater and the system of reheater tube
Producing material material first-selection is all Super304H steel.
But, the superheater of extra-supercritical unit and the service temperature (about 600 DEG C) of reheater tube are just located
In the central area of the sensitizing temperature (450～825 DEG C) of Super304H steel, C high in Super304H steel
Content necessarily makes chromium-rich carbide (Cr23C6) be easier to separate out at crystal boundary and form Cr depletion zone, cause
Super304H steel has higher Susceptibility To Intergranular Corrosion.In recent years, domestic multiple ultra supercritical pot is being built
Stove there occurs serious Super304H pipe Susceptibility To Intergranular Corrosion induction stress corrosion in the water pressure testing stage
Pipe explosion accident.Therefore, develop a kind of method eliminating Super304H steel Susceptibility To Intergranular Corrosion, for
Reduce ultra-supercritical boiler superheater and the generation of reheater tube quick-fried leakage accident, improve ultra-supercritical boiler
Safety operation level has very important significance.
It is known that the reason of austenitic stainless steel generation intercrystalline corrosion be carbon under sensitizing temperature with chromium-rich
The form of carbide consumes the chromium near crystal boundary when crystal boundary separates out, and makes crystal boundary adjacent domain define lean
Chromium district, becomes sensitive to intercrystalline corrosion, and this process is referred to as " sensitization ".Prevent Super304H the most at present
The measure of steel intercrystalline corrosion mainly separates out consideration from containment carbide at crystal boundary, mainly has: reduce carbon
Content, optimization elemental composition proportioning, solution treatment etc..These measures can be alleviated to a certain extent
The Susceptibility To Intergranular Corrosion of Super304H steel, but there is certain limitation: and (1) reduces C content
Although the precipitation of chromium-rich carbide can be lowered, but solution strengthening and the precipitation strength effect of C will certainly be reduced
Really, the elevated temperature strength of the result material that has been partial sacrifice；(2) elemental composition proportioning is optimized, as Nb is contained
Measure the upper limit that is near the mark, for the Super304H steel limited use of high-carbon；(3) carry out at high temperature solid solution
Reason is M23C6Back dissolving enters matrix, during the military service of follow-up 600 DEG C, still suffers from M23C6At crystal boundary
Separate out, it is impossible to be inherently eliminated the Susceptibility To Intergranular Corrosion of Super304H steel.
Along with aging time extends (under sensitizing temperature), the chromium atom of intra-die can be gradually diffused into crystalline substance
Cr depletion zone near boundary, makes supplementing and spontaneous recovery of Cr depletion zone acquisition chromium atom, and this phenomenon is referred to as " desensitization "
Process.Using Rapid desensitization process is the recommendation technique that ferritic stainless steel eliminates Susceptibility To Intergranular Corrosion,
But owing to Cr diffusion velocity in tradition coarse grained austenite rustless steel is very slow, therefore use desensitization to process consumption
Shi Taichang and lose more than gain.Current research shows, shot blasting on surface grain refining can increase substantially Cr in Austria
Diffusion velocity in family name's body, therefore uses shot blasting on surface grain refining+Rapid desensitization to process and eliminates
Super304H steel Susceptibility To Intergranular Corrosion becomes possibility technically.Its ultimate principle is: material is through overspray
There is large plastometric set after processing in ball, crystal grain is refined to micron order even nanoscale, and crystal boundary ratio significantly carries
Height, intracrystalline produces the defects such as a large amount of deformation twins, dislocation simultaneously, and these tissue change can be in diffusion heat
Two results are brought: 1. a large amount of crystal boundaries and deformation defect make the speed of separating out of carbide faster during process；②
A large amount of crystal boundaries and deformation defect provide a large amount of diffusion " passage " to Cr atom, and Cr atom is greatly improved
Diffusion velocity so that Cr depletion zone can quickly obtain chromium supplement and eliminate.Above-mentioned two aspects are comprehensively made
With the Susceptibility To Intergranular Corrosion that can fast and effeciently eliminate Super304H steel.
Inner wall shot blasting surface grain refining be in Super304H steel moulding process frequently with one of strategy, mesh
Be by promoting that Cr diffusion improves the high-temperature oxidation resistance of austenitic stainless steel.The present invention utilizes this
One shot-blast process, processes by increasing desensitization, on the premise of not expendable material elevated temperature strength, quickly has
Effect ground eliminates the Susceptibility To Intergranular Corrosion of Super304H steel, is that high-carbon Super304H steel intercrystalline corrosion is quick
Perception preferably control method.
Summary of the invention
The technical problem to be solved, it is simply that on the basis of keeping the original elevated temperature strength of material,
A kind of method eliminating Super304H steel Susceptibility To Intergranular Corrosion is provided.The present invention uses following technology hands
Section:
A kind of method eliminating Super304H steel Susceptibility To Intergranular Corrosion, comprises the steps:
(1) prepared by solid solution state sample: Super304H steel pipe is carried out homogenization solution treatment, is organized
Uniform solid solution state sample；Then cut smooth plate tensile sample, carry out surface grinding to flat smooth,
Pretreating specimen as bead；
(2) prepared by shot-peening state sample: arrange certain shot-blast process parameter, the solid solution state to surface grinding
Sample carries out shot blasting on surface process, obtains the plasticity with certain thickness and hardness at solid solution state specimen surface
Deformation layer, obtains shot-peening state sample；
(3) desensitization heat treatment: shot-peening state sample is carried out under uniform temperature and time desensitization process, finally
Obtain the Super304H steel desensitization sample insensitive to intercrystalline corrosion.
Further, the solution treatment concrete operations of described step (1) are: resistance-type heat-treatment furnace is heated
To 1150 DEG C, putting into wherein by Super304H steel pipe, heat in atmosphere, temperature retention time is 30min,
The type of cooling is water-cooled.
Further, the sample of described step (1) cuts concrete operations and is: use WEDM from
Cutting smooth plate sample on Super304H steel pipe, in cutting process, holding coolant cools down.
Further, the surface grinding concrete operations of described step (1) are: depend on the plate tensile sample after cutting
Secondary employing 180, No. 360, the sand paper of No. 800 be ground, grind time often change a sand paper, examination
Sample grind direction will together with upper polishing scratch direction vertical, be milled to the disappearance of one polishing scratch and newly polishing scratch direction equal
Even consistent till.Bruting process is constantly water-cooled, finally with dehydrated alcohol rinse, dry up standby.
Further, the shot blasting on surface process technological parameter of described step (2) including:
Equipment choice: select pressure range to be to the maximum in the pneumatic type compressed air shotblasting machine of 1Mpa, nozzle distance
The operating distance of specimen surface is 50mm；
Bullet selects: use the rustless steel cannonball of a diameter of 0.5mm of shot-peening, when shot peening strength is higher
Generally using cast iron pellets and cast steel ball, cast steel ball toughness is preferable, and the most broken, service life is cast iron pellets
Several times, for improve shot-peening effect stability, use spherical cast steel ball to process；For ensureing
Bead blasted surfaces has less roughness, meets the material required kinetic energy of generation large plastometric set simultaneously, uses
The spherical cast steel bullet of a diameter of 0.5mm of shot-peening；
Pressure is arranged: pressure is 0.5Mpa～0.8Mpa, and pressure is to affect shot-peening energy
The direct factor of size, pressure is the biggest, and the strengthening degree of depth that bombarded surface produces is the deepest, surface peening
Effect is the best, for obtaining preferable surface peening effect, ensures less sample integral macroscopic deformation simultaneously,
Controlling pressure is 0.5Mpa～0.8Mpa；
Shot-peening set of time: the shot-peening time is 5min～30min, high energy shot bombardment material produces plasticity and becomes
Shape, after certain time, surface plastic deformation builds up and is formed one layer of uniform plastic deformation layer；
After plastic deformation layer is formed, continue excessive shot-peening and flow layer can be made to be limited by adjacent domain because radially extending
Make and cause lap to peel off；For preparing certain thickness uniform plastic deformation layer, do not send out simultaneously
Raw pull out type fracture, the control shot-peening time is 5min～30min.
Further, thickness >=70 μm of shot-peening state specimen surface plastic deformation layer in described step (2).
Further, the specific requirement of shot-peening state sample plastic deformation layer's hardness of described step (2) is: away from
Hardness number from μm depths, shot-peening state specimen surface 60 μm ± 10 improves than the hardness number of matrix of samples
More than 100HV.
Further, the shot-peening state sample desensitization process concrete operations of described step (3) are: resistance-type heat
Processing stove and be heated to 700 DEG C, put into wherein by shot-peening state sample, heat in atmosphere, temperature retention time is
120min, the type of cooling is water-cooled.
Compared with the existing measure improving Super304H steel Susceptibility To Intergranular Corrosion, the present invention have as
Lower advantage and beneficial effect:
1. the present invention is on the basis of Super304H steel shot blasting on surface grain refining processes, and uses at desensitization heat
Reason promotes that Cr atoms permeating eliminates the Cr depletion zone formed because of chromium-rich Carbide Precipitation, utilizes dicyclo electrification
Learn reactivation (DL-EPR) and its intercrystalline corrosion sensitivity (degree of can be detected
Sensitization-DOS) drop to insensitive degree, be inherently eliminated the crystalline substance of Super304H steel
Between corrosion susceptibility.
2. it is the step in the current moulding process of Super304H steel that the shot blasting on surface that the present invention uses processes；
The present invention is apt to as utilizing this shot-blast process, simply by increasing a desensitization Technology for Heating Processing, it is possible to
Fast and effeciently eliminate the Susceptibility To Intergranular Corrosion of Super304H steel, without reducing Super304H steel
Carbon content thus sacrifice its elevated temperature strength.Meanwhile, surface shot blasting strengthening can improve material surface mechanics
Performance and high-temperature oxidation resistance, therefore this process can realize Super304H steel in the corruption of anti-intergranular
Erosion performance, antioxygenic property and tripartite's win-win of elevated temperature strength.
Accompanying drawing explanation
Fig. 1 is shot-peening state sample cross displaing micro tissue topography after oxalic acid corrodes in embodiment 1～4
Fig. 2 is the DL-EPR test curve of solid solution state+sensitized treatment sample in embodiment 1～4
Fig. 3 is the DL-EPR test curve that shot-peening state in embodiment 1～4+desensitization processes sample
Fig. 4 is solid solution state+sensitized treatment in embodiment 1～4, shot-peening state+desensitization process sample DL-EPR
Displaing micro tissue topography after test
Detailed description of the invention
Below in conjunction with embodiment, the invention will be further described.
As a example by the supply of material state Super304H steel pipe that SUMITOMO CHEMICAL metal company produces, its composition such as table 1,
Specification is Φ 48 × 10mm, and the concrete operation step of the present invention is described.
The stainless chemical composition of table 1 embodiment Super304H (wt.%)
Embodiment 1:
A kind of method eliminating Super304H steel Susceptibility To Intergranular Corrosion, comprises the steps:
Step 1, prepared by solid solution state sample, specifically include:
Solution treatment: resistance-type heat-treatment furnace is heated to 1150 DEG C, puts into it by Super304H steel pipe
In, heating in atmosphere, temperature retention time is 30min, and the type of cooling is water-cooled；
Cut: use WEDM from Super304H steel pipe, cut a size of 50 × 30 ×
The plate sample of 4mm, in cutting process, holding coolant cools down；
Grind: to cutting after sample use successively No. 180, No. 360, the sand paper of No. 800 carry out fine lapping,
Grind time often change a sand paper, buck direction will together with upper polishing scratch direction vertical, be milled to one
Road polishing scratch disappears and till the uniformity of new polishing scratch direction, bruting process is constantly water-cooled；After grinding
Sample rinses with dehydrated alcohol after rinsing with tap water again, finally dries up, and solid solution state sample is prepared complete,
In being placed in drying baker stand-by.
Step 2, prepared by shot-peening state sample, specifically include:
Shot-blast process parameter is arranged: solid solution state sample is put into pressure range and is the pneumatic of 1Mpa to the maximum
In formula compressed air shotblasting machine, fix sample with steel base, the rustless steel Spherical Projectiles using shot-peening to be a diameter of 0.5mm
Ball, the operating distance of nozzle distance specimen surface is 50mm, keeps nozzle output by regulation pressure valve
Pressure 0.5Mpa, shower nozzle repeatedly swings shot-peening time 8min at specimen surface, obtains shot-peening state sample；
Plastic deformation layer's thickness measure: concrete operations are: 1. use 10% oxalic acid to shot-peening state sample vertical profile
Face carries out electrolytic etching, and electrolysis design parameter is: electric current density 0.1～0.3A/CM2, voltage 6V；2. adopt
With metallurgical microscope, the sample vertical section after electrolytic etching is observed, austenite crystal in plastic deformation layer
Grain is refined, and can calculate shot-peening state sample plastic deformation layer thickness is 125 μm, as it is shown in figure 1,
Meet thickness requirement.
Plastic deformation layer's hardness measurement: use microhardness testers to measure distance shot-peening state sample shot-peening end surfaces
The hardness number of 60 μm depths, microhardness value is 440HV (matrix hardness is 204HV), meets
Hardness requirement.
Step 3, desensitize heat treatment, specifically includes:
Heat treatment: resistance-type heat-treatment furnace is heated to 700 DEG C, puts solid solution state sample and shot-peening state sample
Entering wherein, heat in atmosphere, temperature retention time is 10min, and the type of cooling is water-cooled, respectively obtains solid solution
State+sensitized treatment sample and shot-peening state+desensitization process sample.
Use dicyclo electrochemistry reactivation (DL-EPR) to solid solution state+sensitized treatment sample,
Shot-peening state+desensitization processes sample and tests respectively, records the intercrystalline corrosion of solid solution state+sensitized treatment sample
Sensitivity was 0.1% (as shown in Figure 2), and the intercrystalline corrosion sensitivity that shot-peening state+desensitization processes sample is
31.5% (as shown in Figure 3).Erosion profile after testing in conjunction with sem observation DL-EPR,
From the erosion profile of solid solution state+sensitized treatment sample (as shown in fig. 4 a), it is seen that the crystal boundary of this sample
Clearly, illustrate that intercrystalline corrosion does not occurs in this sample, be consistent with the test result of DL-EPR；And shot-peening state+
Desensitization processes in sample (as shown in fig 4e) erosion profile, and crystal boundary, intracrystalline have been covered with etch pit, whole
Body intercrystalline corrosion is very serious, illustrates that the Susceptibility To Intergranular Corrosion of this sample is the highest, demonstrates DL-EPR
Test result.
Embodiment 2:
The present embodiment is with the difference of embodiment 1: step 3, and desensitize heat treatment, specifically includes:
Heat treatment: resistance-type heat-treatment furnace is heated to 700 DEG C, puts solid solution state sample and shot-peening state sample
Entering wherein, heat in atmosphere, temperature retention time is 20min, and the type of cooling is water-cooled, respectively obtains solid solution
State+sensitized treatment sample and shot-peening state+desensitization process sample.
Use dicyclo electrochemistry reactivation (DL-EPR) to solid solution state+sensitized treatment sample,
Shot-peening state+desensitization processes sample and tests respectively, and relative to embodiment 1, embodiment 2 is at 700 DEG C
Temperature retention time extend to 20min, the intercrystalline corrosion sensitivity of solid solution state+sensitized treatment sample from 10min
Brought up to for 1.4% (as shown in Figure 2) from 0.1%, and the intercrystalline corrosion that shot-peening state+desensitization processes sample is sensitive
Degree was but reduced to for 18.4% (as shown in Figure 3) from 31.5%.In conjunction with sem observation DL-EPR
Erosion profile after test, from the erosion profile of solid solution state+sensitized treatment sample (as shown in Figure 4 b),
The crystal boundary of this sample visible is more complete, clear, etch pit seldom occurs, illustrates that this sample does not occur
Intercrystalline corrosion, is consistent with the test result of DL-EPR；And shot-peening state+desensitization processes sample (such as Fig. 4 f
Shown in) in erosion profile, be locally covered with etch pit on crystal boundary, intracrystalline, compared solid solution state+sensitized treatment
Sample, this sample entirety intercrystalline corrosion ratio is more serious, but the intergranular comparing this sample in embodiment 1 is rotten
Degree of corrosion is little, is consistent with the test result variation tendency of DL-EPR.
Embodiment 3:
The present embodiment is with the difference of embodiment 1: step 3, and desensitize heat treatment, specifically includes:
Heat treatment: resistance-type heat-treatment furnace is heated to 700 DEG C, puts solid solution state sample and shot-peening state sample
Entering wherein, heat in atmosphere, temperature retention time is 120min, and the type of cooling is water-cooled, respectively obtains solid
Solvent+sensitized treatment sample and shot-peening state+desensitization process sample.
Use dicyclo electrochemistry reactivation (DL-EPR) to solid solution state+sensitized treatment sample,
Shot-peening state+desensitization processes sample and tests respectively, and relative to embodiment 1, embodiment 3 is at 700 DEG C
Temperature retention time extend to 120min, the intercrystalline corrosion sensitivity of solid solution state+sensitized treatment sample from 10min
Brought up to for 17.1% (as shown in Figure 2) from 0.1%, and the intercrystalline corrosion that shot-peening state+desensitization processes sample is quick
Sensitivity was but rapidly reduced to for 1.9% (as shown in Figure 3) from 31.5%.In conjunction with sem observation
Erosion profile after DL-EPR test, from the corrosion of solid solution state+sensitized treatment sample (as illustrated in fig. 4 c)
In pattern, it is seen that corrode ditch with the presence of continuous print on crystal boundary, illustrate that overall chromium depleted situation is more serious, brilliant
Between corrosion-susceptible degree relatively big, be consistent with the test result of DL-EPR；And shot-peening state+desensitization process sample (as
Shown in Fig. 4 g) in erosion profile, intracrystalline exists, near crystal boundary almost without corrosion pit or corrosion ditch
Cr depletion zone has been obtained for effectively repairing, and is consistent with the test result variation tendency of DL-EPR, and this shows
Shot-peening state sample has preferable intergranular corrosion resistance ability after 700 DEG C/120min desensitization processes.For
Solid solution aspect product, 700 DEG C/120min remains at the sensitization stage after processing；For shot-peening aspect product, 700 DEG C
Already at desensitization phase after/120min process.
Embodiment 4:
The present embodiment is with the difference of embodiment 1: step 3, and desensitize heat treatment, specifically includes:
Heat treatment: resistance-type heat-treatment furnace is heated to 700 DEG C, puts solid solution state sample and shot-peening state sample
Entering wherein, heat in atmosphere, temperature retention time is 480min, and the type of cooling is water-cooled, respectively obtains solid
Solvent+sensitized treatment sample and shot-peening state+sensitized treatment sample.
Use dicyclo electrochemistry reactivation (DL-EPR) to solid solution state+sensitized treatment sample,
Shot-peening state+desensitization processes sample and tests respectively, and relative to embodiment 1, the present embodiment 4 is at 700 DEG C
Under temperature retention time extend to 480min from 10min, the intercrystalline corrosion of solid solution state+sensitized treatment sample is sensitive
Spend and brought up to for 33.7% (as shown in Figure 2) from 0.1%, and shot-peening state+desensitization processes the intercrystalline corrosion of sample
Sensitivity was but rapidly reduced to for 1.2% (as shown in Figure 3) from 31.5%.In conjunction with sem observation
Erosion profile after DL-EPR test, from the corrosion of solid solution state+sensitized treatment sample (as shown in figure 4d)
In pattern, it is seen that occur on crystal boundary that continuous print etch pit forms the erosion profile of " ditch shape ", corrosion
Trench depth is relatively deep, the corrosion-free sign of intracrystalline, and this illustrates that this sample there occurs serious intercrystalline corrosion, with
The test result of DL-EPR is consistent；And shot-peening state+desensitization processes sample (as shown in figure 4h) erosion profile
In, intracrystalline is almost without evidence of corrosion, and this shows that near crystal boundary, Cr depletion zone has been obtained for effectively repairing,
It is consistent with the test result variation tendency of DL-EPR.For solid solution aspect product, 700 DEG C/480min process
After remain at the sensitization stage；For shot-peening aspect product, already at completely after 700 DEG C/480min process
Desensitization phase.
The intercrystalline corrosion sensitivity test result of the Super304H steel of the present embodiment 1～4 is as shown in table 2.
The test result of the Super304H steel of table 2 the present embodiment 1～4
From the point of view of DL-EPR test result (such as Fig. 2 and Fig. 3), along with the prolongation of temperature retention time, solid solution
The intercrystalline corrosion sensitivity of state Super304H steel is gradually increased, but the intergranular of shot-peening state Super304H steel
Corrosion-susceptible degree is then gradually reduced, and after 700 DEG C/120min, (embodiment 3) minimizes and tend towards stability,
Holding time is to after 480min, and the intercrystalline corrosion sensitivity of shot-peening state sample is low to being negligible
Degree.
Embodiment 1～4 shows: processes technique by controlling the shot blasting on surface of Super304H steel, makes sample
Surface grain refinement to micron order even nanoscale, crystal boundary ratio be greatly improved and produce a large amount of deformation twins,
The defects such as dislocation density, provide " passage " of the diffusion of a large amount of long-range for Cr atom.Desensitized by increase
Heat treatment, the long-range diffusion that Cr depletion zone can be made quickly to obtain matrix chromium supplements, thus quickly eliminates because of richness
The Cr depletion zone that chromium carbide separates out and formed, reduces the Susceptibility To Intergranular Corrosion of Super304H steel.Along with
The prolongation of sensitization temperature retention time, the intercrystalline corrosion sensitivity of shot-peening state Super304H steel is gradually reduced finally
Tend towards stability.In view of the work efficiency of commercial Application, on the premise of reaching desensitization purpose, select to protect
The Technology for Heating Processing that the temperature time is shorter.Therefore, above-described embodiment 3 is the present invention preferably embodiment.
Embodiments of the present invention are not limited to above-described embodiment.Use and patent above-described embodiment of the present invention
Identical or the method for approximation and other modes of obtaining, all within protection scope of the present invention.
Claims (9)
1. the method eliminating Super304H steel Susceptibility To Intergranular Corrosion, it is characterised in that include as
Lower step:
(1) prepared by solid solution state sample: Super304H steel pipe is carried out homogenization solution treatment, is organized
Uniform solid solution state sample；Then cut smooth plate tensile sample, carry out surface grinding to flat smooth,
Pretreating specimen as bead；
(2) prepared by shot-peening state sample: arrange certain shot-blast process parameter, the solid solution state to surface grinding
Sample carries out shot blasting on surface process, obtains the plasticity with certain thickness and hardness at solid solution state specimen surface
Deformation layer, obtains shot-peening state sample；
(3) desensitization heat treatment: shot-peening state sample is carried out under uniform temperature and time desensitization process, finally
Obtain the Super304H steel desensitization sample insensitive to intercrystalline corrosion.
The method of elimination Super304H steel Susceptibility To Intergranular Corrosion the most according to claim 1, its
It is characterised by: the described Super304H tube material in step (1) is the heat-resisting austenite of Super304H
Rustless steel.
The method of elimination Super304H steel Susceptibility To Intergranular Corrosion the most according to claim 1, its
It is characterised by: the homogenization solution treatment concrete operations of described step (1) are: resistance-type heat-treatment furnace is added
Super304H steel pipe, to 1150 DEG C, is put into wherein, is heated in atmosphere by heat, and temperature retention time is 30min,
The type of cooling is water-cooled.
The method of elimination Super304H steel Susceptibility To Intergranular Corrosion the most according to claim 1, its
Be characterised by: the concrete operations that the sample of described step (1) cuts are: use Wire EDM from
Cutting smooth plate sample on Super304H steel pipe, in cutting process, holding coolant cools down.
The method of elimination Super304H steel Susceptibility To Intergranular Corrosion the most according to claim 1, its
It is characterised by: the surface grinding concrete operations of described step (1) are: the plate tensile sample after cutting is adopted successively
With No. 180, No. 360, the sand paper of No. 800 be ground, grind time often change a sand paper, sample grinds
Mill direction will together with upper polishing scratch direction vertical, be milled to the disappearance of one polishing scratch and new polishing scratch direction uniform
Till cause, bruting process is constantly water-cooled, finally with dehydrated alcohol rinse, dry up standby.
The method of elimination Super304H steel Susceptibility To Intergranular Corrosion the most according to claim 1, its
It is characterised by: the shot blasting on surface of described step (2) processes technological parameter and includes:
Equipment choice: select pressure range to be to the maximum in the pneumatic type compressed air shotblasting machine of 1Mpa, nozzle distance
The operating distance of specimen surface is 50mm；
Bullet selects: use the rustless steel cannonball of a diameter of 0.5mm of shot-peening；
Pressure is arranged: pressure is 0.5Mpa～0.8Mpa；
Shot-peening set of time: the shot-peening time is 5min～30min.
The method of elimination Super304H steel Susceptibility To Intergranular Corrosion the most according to claim 1, its
It is characterised by: thickness >=70 μm of shot-peening state specimen surface plastic deformation layer in described step (2).
The method of elimination Super304H steel Susceptibility To Intergranular Corrosion the most according to claim 1, its
It is characterised by: the specific requirement of shot-peening state sample plastic deformation layer's hardness of described step (2) is: distance spray
The hardness number of μm depths, ball state specimen surface 60 μm ± 10 improves 100HV than the hardness number of matrix of samples
Above.
The method of elimination Super304H steel Susceptibility To Intergranular Corrosion the most according to claim 1, its
It is characterised by: the concrete operations that the shot-peening state sample desensitization of described step (3) processes are: at resistance-type heat
Reason stove is heated to 700 DEG C, puts into wherein by shot-peening state sample, heats in atmosphere, and temperature retention time is
120min, the type of cooling is water-cooled.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610178397.2A CN105842308A (en) | 2016-03-25 | 2016-03-25 | Method for eliminating super 304H steel inter-granular corrosion sensitivity |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610178397.2A CN105842308A (en) | 2016-03-25 | 2016-03-25 | Method for eliminating super 304H steel inter-granular corrosion sensitivity |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN105842308A true CN105842308A (en) | 2016-08-10 |
Family
ID=56583585
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610178397.2A Pending CN105842308A (en) | 2016-03-25 | 2016-03-25 | Method for eliminating super 304H steel inter-granular corrosion sensitivity |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105842308A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107502721A (en) * | 2017-07-12 | 2017-12-22 | 华南理工大学 | A kind of preparation method of high-strength, high-toughness stainless steel |
| CN108300844A (en) * | 2018-01-24 | 2018-07-20 | 中南大学 | A kind of anti-corrosion " sandwich " structure and its construction method |
| CN110195152A (en) * | 2019-06-11 | 2019-09-03 | 河南神州精工制造股份有限公司 | A method of improving austenitic stainless steel anti intercrystalline corrosion ability |
| CN110686955A (en) * | 2019-11-19 | 2020-01-14 | 南昌航空大学 | Method for reducing surface roughness of Ti-10V-2Fe-3Al alloy strengthened layer |
| CN111005020A (en) * | 2019-12-10 | 2020-04-14 | 清华大学 | Method for preventing liquefaction cracks |
| CN113637830A (en) * | 2021-07-21 | 2021-11-12 | 广州大学 | Method for accelerating sigma phase nucleation and growth of high-carbon austenitic heat-resistant steel |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4588440A (en) * | 1984-06-28 | 1986-05-13 | Hydro Quebec | Co containing austenitic stainless steel with high cavitation erosion resistance |
| CN103014277A (en) * | 2012-12-07 | 2013-04-03 | 南京理工大学 | Method for controlling austenitic stainless steel surface grain boundary structure |
| CN104593571A (en) * | 2015-01-16 | 2015-05-06 | 上海大学 | Grain boundary engineering process method for improving corrosion resistance of stainless steel 316 |
| CN105420472A (en) * | 2015-11-11 | 2016-03-23 | 上海大学 | Grain boundary engineering technique for improving corrosion resistance of 316Lmod stainless steel |
-
2016
- 2016-03-25 CN CN201610178397.2A patent/CN105842308A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4588440A (en) * | 1984-06-28 | 1986-05-13 | Hydro Quebec | Co containing austenitic stainless steel with high cavitation erosion resistance |
| CN103014277A (en) * | 2012-12-07 | 2013-04-03 | 南京理工大学 | Method for controlling austenitic stainless steel surface grain boundary structure |
| CN104593571A (en) * | 2015-01-16 | 2015-05-06 | 上海大学 | Grain boundary engineering process method for improving corrosion resistance of stainless steel 316 |
| CN105420472A (en) * | 2015-11-11 | 2016-03-23 | 上海大学 | Grain boundary engineering technique for improving corrosion resistance of 316Lmod stainless steel |
Non-Patent Citations (1)
| Title |
|---|
| RUI KUN WANG等: "Effect of Shot Peening on the Intergranular Corrosion Susceptibility of a Novel Super304H Austenitic Stainless Steel", 《JMEPEG》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107502721A (en) * | 2017-07-12 | 2017-12-22 | 华南理工大学 | A kind of preparation method of high-strength, high-toughness stainless steel |
| CN108300844A (en) * | 2018-01-24 | 2018-07-20 | 中南大学 | A kind of anti-corrosion " sandwich " structure and its construction method |
| CN110195152A (en) * | 2019-06-11 | 2019-09-03 | 河南神州精工制造股份有限公司 | A method of improving austenitic stainless steel anti intercrystalline corrosion ability |
| CN110686955A (en) * | 2019-11-19 | 2020-01-14 | 南昌航空大学 | Method for reducing surface roughness of Ti-10V-2Fe-3Al alloy strengthened layer |
| CN111005020A (en) * | 2019-12-10 | 2020-04-14 | 清华大学 | Method for preventing liquefaction cracks |
| CN113637830A (en) * | 2021-07-21 | 2021-11-12 | 广州大学 | Method for accelerating sigma phase nucleation and growth of high-carbon austenitic heat-resistant steel |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105842308A (en) | Method for eliminating super 304H steel inter-granular corrosion sensitivity | |
| CN101187441B (en) | Super-pressure hydrogen cylinder manufacture method | |
| Guo et al. | Corrosion resistance of candidate cladding materials for supercritical water reactor | |
| Meng et al. | The role of TiN inclusions in stress corrosion crack initiation for Alloy 690TT in high-temperature and high-pressure water | |
| US4077812A (en) | Method of working steel machine parts including machining during quench cooling | |
| CN104977299B (en) | A kind of method for showing P91, P92 ferritic heat-resistant steel original austenite crystal prevention | |
| Chen et al. | Investigation on the impact wear behavior of 2.25 Cr–1Mo steel at elevated temperature | |
| Yao et al. | A novel cold expansion process for improving the surface integrity and fatigue life of small-deep holes in Inconel 718 superalloys | |
| Frömert et al. | Investment Casting and Mechanical Properties of Open‐Cell Steel Foams | |
| CN112251666A (en) | Austenitic stainless steel forging for spent fuel post-treatment and manufacturing method thereof | |
| CN104227161A (en) | Process for combined machining of carburizing camshaft in electrolytic grinding mode | |
| Jung et al. | Enhanced resistance to delayed cracking in deep-drawn lean duplex stainless steel: the role of residual stress | |
| CN101551197A (en) | A pyrite-based sulphuric acid roaster cooling calandria repairing method | |
| Gou et al. | Effect of hydrogen on impact fracture of X80 steel weld: Various heat inputs and coarse grain heat-affected zone | |
| Toda et al. | Improvement in creep strength of precipitation strengthened 15Cr ferritic steel by controlling carbon and nitrogen contents | |
| CN113637830A (en) | Method for accelerating sigma phase nucleation and growth of high-carbon austenitic heat-resistant steel | |
| DK2761040T3 (en) | Process for producing a wear and corrosion resistant casing for a nuclear reactor from a low carbon content stainless steel austenitic blank, corresponding casing and corresponding control cluster | |
| HAN et al. | Austenite Grain Growth Behavior of Vanadium Microalloying Medium Manganese Martensitic Wear-Resistant Steel | |
| CN109352265A (en) | A kind of propeller processing technique | |
| Shichao et al. | Study on grinding strengthening and hardening mechanism under small depth of cut conditions | |
| CN103958721B (en) | Produce the method for the wear-resistant and corrosion resistant parts of stainless steel for nuclear reactor, corresponding part and control cluster accordingly | |
| Kikuchi et al. | Effect of fine particle peening on oxidation resistance of austenitic stainless steel | |
| Yanfei et al. | Effect of grain size on hydrogen embrittlement of 304L austenitic stainless steel | |
| Shen | Review of the Effect of Cold Work on Stress Corrosion Cracking | |
| Vasudevan et al. | Investigation of the Use of Laser Shock Peening for Enhancing Fatigue and Stress Corrosion Cracking Resistance of Nuclear Energy Materials |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20160810 |
|
| WD01 | Invention patent application deemed withdrawn after publication |