Special anti-corrosion metal coatingNPS、Ni-P alloy cladding(HAILIN system )
Ni—P scope of cladding
1. Column tube, carbon-steel water cooler, air cooler ,re-boiler tube and other non-style heat exchanger.
2.Working temperature is within 700℃.
3.Protection of steel pipes, tubes, shell and impellers of mud pump, column pump and submersible pump.
Implementation standards
GB/T13913《rules and testing methods for metal layer by chemical Ni- P alloy paiting》
Ni—P suitable medium for cladding
1.Freshwater, salt water, ocean water, industrial cycling water, distilled water and vaor.
2.Chemical medium with acid-resistance, alkali-resistance , salt-resistance and sewage resistance.
3.All types of oil medium and benzene, hydrogen sulfide.
Ni—P technical index of cladding
1.ISO 2819 testing method and review on bonding strength of coating
2.Ni—P test and evaluate the coating of alloy coating according to international standard ISO 4527:
A.ISO 2819 testing method and review on bonding strength of coating
B.ISO 3768 neutral salt-spray test for coating(NNStest)
C.ISO 3700 copper accelerated salt-spray test for coating(CASS test)
D.ISO 4516 vickers hardness and knoop hardness test for coating
E.ISO 4527 thickness testing standard for coating
F.ISO 4527 porosity testing standard of coating
G.ISO 4527 phosphorus testing standard for coating
3.Ni—P physical performance of alloy coating:Chamfering the Column steel with 50μm, the coating no caving, no cracks, means good cohesion between coating and steel.( see list7, list 8)
Ni—P physical performance of alloy coatin
試驗項目
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結果
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試驗方法
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硬度 HV50
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鍍態550 熱處理后950
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ISO 4527 6.4
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內應力kgf/mm
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-3.7-4.1
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附著力 熱震,300℃
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1級
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ISO 4527 6.5
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Taber磨損試驗指數 磨輪CS-17
失重mg/1000CyCles
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鍍態、14.524
熱處理后3.34
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ISO 4527 6.9
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Not:Ni—P physical mechanical performance of coating
Ni—P testing results of coating hardness shows that the hardness of low Ni coating with 1~4Wt%P is around 700HV, the hardness can reach 1000HV after heat treatment, which is close to or even exceed the hard Cr. Coating, and it can substitute the hard Cr. Coating in some conditions.
Mechanical performance of Ni—P alloy coating
機械性能
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1-4Wt%p
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7-9Wt%p
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10-12Wt%p
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楊氏模數(GPa)
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50-52
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50-60 60-66(4-7Wt%p)
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50-60
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拉伸強度(Mpa)
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150-200
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800-1100
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750-900
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(鋼鐵上)內應力(KP/mm)
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-+10
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-±5
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--5
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延伸率
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<0.5
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-0.7
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-1.5
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鍍后硬度(HRC)
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650-700
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550-600
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500-550
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400℃熱處理1小時(HRC)
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-1000
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-1030
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-1050
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Corrosion rate of Chemical Ni—P(10%) alloy coating in all kinds of medium
介質分類
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介質名稱
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介質溫度℃
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腐蝕率mm/Y
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Ni-p
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Cr18Ni9不銹鋼
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水
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海水
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30
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0.0385
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>1.5
|
|
|
50
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0.253
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>1.5
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酸溶液
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30%HCl
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30
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0.407
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>1.5
|
|
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50
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1.001
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>1.5
|
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10%H2SO4
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30
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0.0424
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>1.5
|
|
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60
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0.185
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>1.5
|
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38%H3PO4
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60
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0.0632
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>1.5
|
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16%HNO3
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30
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72.45
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<0.05
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35%草酸
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沸騰
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0.0363
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>1.5G
|
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28%醋酸
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沸騰
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0.0779
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>1.5
|
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50%檸檬酸
|
60
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0.0350
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0.05-0.5G
|
|
40%氫氟酸
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30
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0.0141
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<1.5G.S
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堿溶液
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20%NaOH
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沸騰
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<0.048
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>1.5
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鹽溶液
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30%次氯酸鈉
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50
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<0.001
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>1.5P.G
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|
20%過氯酸鈉
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沸騰
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<0.001
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0.05-0.5
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20%重鉻酸鉀
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沸騰
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<0.001
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0.5-1.5
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20%氯化銨
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沸騰
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0.0874
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0.5-1.5
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Not:From this comparison, carbon-steel coatingNi—P spends lower cost than stainless steel , meanwhile the function of anti-corrosion and anti-abrasion is superior to 316 stainless steel ,glasses and fluorine plastics. Therefore it’s reasonable from all respects including anti-corrosion and useful life.
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