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Hydrojet Pretreatment to Accelerate Weathering Steel Producing a Rich Rust Patina

The Following Two Pictures are The Natural Rust of Weathering Steel and The Rust-pretreatment of Corten Steel.
   

Hydrojet Pretreatment to Accelerate Weathering Steel Producing a Rich Rust Patina

ABSTRACT

This invention involves a kind of handling solution about rust patina of Weathering Resistant Steel, belonging to Anti-corrosion technology fields. 0.6% NaCl, 0.9% FeS04, 0.6% CuS04 and 0.9% NaHS03 weight percentages in the invention are blended with water equably so that handling hydroject could be sprayed on the surface of Weathering Steel. Chemical components from liquor form a bed of even, compact and protective rust patina in chemical reaction with steel body, which makes Weather Resistant Steel more beautiful in use time, and prevent hydrojet from running to protect environment without contamination. This invention is easy to be operated and used in bridges, construction, transportation and other Wear Resistant Steel project structure widely because of its short period.

CLAIMS
A kind of handling solution of Pre-weathered Steel, its features are here. And following steps of the solution will be given:
First, oxide skin on steel body surface will be wiped through shot blasting or acid pickling. After wiping oil through acetone, and clean and dry under the function of absolute ethyl alcohol;
Second, confect surface handling hydrojet of Weathered Metal, and then pour it into bucket (0.6% NaCl, 0.9% FeSO4, 0.6% CuSO4 and 0.9% NaHSO3 weight percentages are blended with water) and whip equably when liquor shows azure, that’s handling hydrojet of Wear Resistant Steel;
Third, inject well hydrojet into spray, and spray it on steel surface for 3-5 seconds equably until the color turning brown. After once, let it dry naturally. At this time, absorb residual hydrojet on steel bottom through absorbent material in order to fix time overall. After dry, spray and dry twice to ensure a even and compact rust patina forming.

DESCRIPTION
Hydrojet handling solutions about accelerating stable rust patina of Atmospheric Corrosion Resistant Steel.

Technology
[0001]This invention belongs to steel Anti-corrosion Technology field, involving steel materials corrode in atmosphere environment, particularly surface handling technology of Atmospheric Weather Steel.

Background
[0002]Anti-corrosion Structural Steel decreases corrosion rate rapidly in virtue of surface protective rust patina, but in natural condition, forming the protective surface rust patina usually need several years. Before the protective rust patina, steel structure is in bad condition and produce iron solution contaminating environment.
[0003]Japanese scholars had begun to study stable handling technology of Weathering Resistant Steel rust patina since 1955. This technology was used before Weathering Steel. In order to sharpen stable rust patina process of Weather Resistant Steel. Not only could Wear Resistant Steel avoids yellow hanging phenomenon, but also can prevent contamination and forms a stable protective rust patina. Now, practical rust patina stable handling technology has:①weathering coating handle and oxide coating handle;③rust coating N handle(overall corrosion control [J],2006,20 (4): 5-9). Recently, mature stable handle technology has not been produced in our country. Pre-weathered Steel upkeep is coating, hot-dip galvanizing and aluminum mainly.
[0004]Although foreign stable rust solutions could reduce rust liquid pollution and accelerate rust patina steady, which will improve steel appearance. But these solutions costs are higher and technology is complex. And the steady rust patina need one year or so.

Invention contents
[0005]To overcome the disadvantages of stable rust patina technology, this invention comes up with a solution that spray the solution to naked steel to form stable rust patina, which could form protective rust patina faster. Preventing steel is polluted by rust liquid in use time reducing the complex degree and costs.
[0006]Thus, this invention aim at raising a kind of Weathered Metal rust stable handling solution, which features are here and contain these procedures.
[0007]First, wipe oxide skin on steel body surface through shot blasting and pickling.
[0008]Secondly, confect Corrosion Resistant Steel surface hydrojet, blend the weight percentage 0.1%〜3% NaCl, 0.3%〜3% FeS04, 0.1 %〜3 % CuS04 and 0.3 %〜3 % NaHS03 with water and pour into bucket. And then whip equably until solution turns azure.
[0009]Thirdly, inject Anti-corrosion Structural Steel product surface hydrojet into spray. Spray equably on steel surface for 3-5 seconds until surface turns brown. After once, let steel dry naturally. At this time, you’d better absorb residual liquid on steel bottom through absorbent material to fix dry time overall. After steel structure dry, spray again and dry twice to ensure a even and compact rust patina forming on the weathering resistant steel surface.
[0010]This solution is the first to handle naked Atmospheric Corrosion Resistant Steel surface directly using self-regulating hydrojet. Thereinto, hydrojet could increase and decrease its corrosion capacity to form thicker rust patina; Accelerate a -FeOOH forming; Add CuS04 could make Cu gather on rust patina; And add other chemical components making steel body be corroded equably and formed an even rust patina. Undergo the handle from this hydrojet, Atmospheric Weather Steel is more beautiful and prevent rust liquid away, without environment contamination. This technology is easy to operate and used in many situations widely for short period.
[0011]The additional respects and advantages of this invention will be given in following description. Partial items will be appeared obviously through it and others will be known through practice.
Picture Explanation



[0012] Picture 1 Fe element distribution of Weather Resistant Steel section undergo surface hydrojet handling.
[0013] Picture 2 O element distribution of Weather Resistant Steel section undergo surface hydrojet handling.
[0014] Picture 3 Cu element distribution of Weather Resistant Steel section undergo surface hydrojet handling.
[0015] Picture 4 Cr element distribution of Weather Resistant Steel section undergo surface hydrojet handling.



[0016] Picture 5 Weather Resistant Steel process picture undergo surface handling hydrojet.
[0017] Practice Case 1
[0018] This practice case contains following procedures based on Weathering Steel surface technology when it is used in speed-up experiment.
[0019] Procedure 1. Cut COR-TEN steel into 50mmX 50mm. After wiping oil with acetone, clean it through absolute ethyl alcohol and dry it.
[0020] Procedure 2. Confect 10g Wear Resistant Steel surface handling liquid(0.6% NaCl + 0.9% FeS04 + 0.6% CuS04 + 0.9% NaHS03). Utilize Pre-weathered Steel product handling hydrojet to spray Weathered Metal sample. After sample surface dry, spray handling hydrojet again twice. And then spray with running water to product samples to wipe rust. And observe rust section situation through scan electric mirror, and analyze elements distribution condition of rust patina through energy spectrum.
[0021] Procedure 3 Have sprayed 0.5% NaCl on steel including naked and surface handling hydrojet for 10 days. And time interval is 12 hours once to test Corrosion Resistant Steel could maintain good aspect preventing rust hydrojet away or not after handling. The whole process is shown in picture 5.
[0022] After handling, the rust patina on Atmospheric Corrosion Resistant Steel looks well equably.
[0023] Fe and O elements gather situations of Atmospheric Weather Steel undergoing handling are shown in picture 3 and 4 apart. The thickness of rust patina on the Anti-corrosion Structural Steel after handling is 20 um from the picture.
[0024] Cu and Cr elements gather situations of Weathering Resistant Steel undergoing handling are shown in picture 3 and 4 apart. These two elements gather in rust patina of Weathering Steel from the picture.
[0025] Naked Wear Resistant Steel has been corroded in 0.5% NaCl condition for 5 days. And the corrosion layer is not even. Most of areas could be covered by rust patina over 10 days, but the layer color is not still even. However, Pre-weathered Steel after handling has been corroded for 5 or 10 days. And its aspect is fixed and rust patina is even. The maximum of running rust of Weathered Metal after handling is lesser than that steel without handling distinctly.

Main Products Showing:
ASTM ASME EN JIS UNI NFA
Corten A SA588 Gr.A S235J2W SPA-H Fe 360 DK1 E24W4
Corten B SA588 Gr.B S355J2WP SMA490AW Fe 510 C1K1 E36WA3
A588 Gr.A SA588 Gr.C S355J0W SMA490BW Fe 510 D1K1 E36WA4
A588 Gr.B SA588 Gr.K S355J0WP SMA490CW Fe 510 C2K1 E36WB3
A588 Gr.C SA871 Type I Gr.60 S355J2G1W SMA400AW Fe 510 D2K1 E36WB4
A242 SA871 Type I Gr.65 S355J2G2W SMA400BW WR 50 A WT St37-3
A709 Gr.50W SA871 Type II Gr.60 S355K2G1W SMA50AW WR 50 B WT St52-3
  SA871 Type II Gr.65 S355K2G2W SMA50CP WR 50 C  
  SA871 Type III Gr.60        
  SA871 Type III Gr.65