Passivation of Stainless Steel – ASTM A967, AMS 2700 & QQ-P-35
不锈钢的钝化是从不锈钢组分表面去除游离铁的过程，同时促进形成薄，致密的氧化物保护屏障的形成。电子游艺棋牌先进的电镀技术，威斯康星州密尔沃基公司，是一个行业领先的不锈钢钝化提供者ASTM A967, AMS 2700 and QQ-P-35 specifications, employing both citric and nitric acid methods. APT provides both competitive high-volume commercial stainless steel passivation as well asprecision medical passivation钛和其他医疗级合金包括钴铬，MP35N和316LVM，利用超声波系统来苛刻的医疗和牙科行业内的应用。APT提供各个部门的钝化，包括医疗，牙科，航空航天，电力传输/分配，重型设备和汽油化工行业。
Passivation of Stainless Steel Properties
Stainless steel or corrosion-resistant steel (CRES) is defined as a steel alloy with a minimum of 11% chromium content by weight. Many alloys of stainless steel include substantial nickel to further enhance the corrosion resistance. In general, stainless steel is broken down into three main groups based upon the alloying elements and
compositions as follows: 1) Austenitic Grades (all 200 & 300-series), 2) Ferritic Grades (part of the 400-series, low carbon alloys) and 3) Martensitic Grades (part of the 400-series, higher carbon alloys).
The reason for the stain-less nature of stainless steel is due to the formation of a thin, adherent and passive (nonreactive) film of nickel & chromium oxides that forms a barrier to prevent further surface corrosion of the product. This is in stark contrast to iron oxide (red rust) that forms on plain carbon steel products. Iron oxide is a loose, scaly oxide that easily falls away to allow the formation of additional iron oxide, thereby perpetuating the corrosion reaction.
当制造不锈钢产品时，自由铁从制造过程中使用的钢切割，冲压和成型工具转移到材料表面。通过抛光或爆破操作，在表面上也可以在表面上施加自由钢，其在温和钢和耐腐蚀钢等级之间使用相同的抛光或爆破介质。自由铁容易氧化，在产品表面上形成可见锈蚀。钝化是具有特定酸配方的化学处理，其除去不锈钢的自由 - 铁或其他表面污染，同时促进无源铬/氧化镍层的形成，以充当进一步腐蚀的屏障。
It is important to note that stainless steel is corrosion resistant but not corrosion proof. The degree of corrosion resistance of a stainless steel alloy is a function of the alloying composition, heat treatment, internal stresses and passivation treatment. An example of this phenomenon is 303 free-machining stainless steel which has notably less corrosion resistance than 304 stainless steel due to the higher concentration of sulfur and phosphorous that imparts the desired machinability of the 303 grade. As a general rule, the higher the nickel and chromium content in the alloy, the more corrosion resistance it will have.
Passivation of Stainless Steel – Advanced Plating Technologies’ Capabilities
Specifications:
ASTM A967
AMS 2700
QQ-P-35
ASTM 380.
ASTM F86.
AMS 2700
ISO 16048
Most Company Specifications
Types:
Precision Medical-Grade Passivation
商业钝化
A-A-A (Alkaline-Acid-Alkaline) Passivation
Stainless Steel Grades Passivated:
Austenitic Grades (All 200 & 300 series)
Ferritic Grades (Part of 400 series and low carbon alloys)
Martensitic Grades (Part of 400 series and higher carbon alloys)
Medical & Exotic Alloys: Titanium, MP35N, 316LVM, Cobalt-Chromium, Inconel, Nickel-Alloys (Nickel 200), Kovar, Invar
Part Size Limitations:24英寸x 28英寸x 10英寸
Heat Treatments Offered:
Hydrogen Embrittlement Bakes
压力缓解烘焙
高温烘烤高达750F
Methods:
Nitric Acid Passivation
柠檬酸钝化
CITRISURF钝化
A-A-A (Alkaline-Acid-Alkaline) Passivation (Citric or Nitric)
不锈钢规格的钝化
Advanced Plating Technologies, offers passivation all methods listed within ASTM A967, AMS 2700 and QQ-P-35. In addition, APT can meet the requirements of any company-specific nitric or citric acid stainless steel passivation methods. Our company also provides passivation of stainless steel to the木匠a-a-a-a process钝化难以使用的不锈钢合金，包括高硫加工303或416合金以及高铬合金，如440不锈钢（参考：A-A-A-A-A-A-A-A-A-A钝化方法制品）Metal Finishing White Papers部分）。可抑制钝化溶液可用于保持不锈钢组件的明亮表面，例如加工面和无心地303或416不锈钢轴。
Unfortunately, very few part prints indicate the specific method to be employed. This opens the door for finishing job shops to use any convenient method they have available resulting in a part that has been passivated but is not truly passive (reference:我所钝化的“不锈钢”钢产品正在展示腐蚀，如何防止这种情况？在我们的Plating Topics部分）。
APT在钝化方面的广泛经验确保将选择正确的钝化方法以匹配特定的不锈钢等级。电子游艺棋牌高级电镀技术提供完整的内部测试服务，以证明我们的不锈钢钝化性能，包括高湿度，每次ASTM B117，铁氰化钾钾
最常见的不锈钢钝化specifications certified by Advanced Plating Technologies are ASTM A967, AMS 2700 and QQ-P-35. APT can also certify passivation to ASTM A380, ASTM F86, AMS 2700C, ISO 16048 as well as most company-specific passivation specifications. A summary of stainless steel passivation techniques per the common ASTM, AMS and Mil specs is as follows:
钝化不锈钢至ASTM A967
Five nitric and citric methods are listed as follows:
Nitric 1: 20-25 v% Nitric Acid, 2.5 w% Sodium Dichromate, 120-130F, 20 Mins minimum
Nitric 2: 20-45 v% Nitric Acid, 70-90F, 30 Mins minimum
硝酸3：20-25 v％硝酸，120-140°F，最小20分钟
硝酸4：45-55 V％硝酸，120-130F，最小30分钟
Nitric 5: Other combinations of temperature, time, and acid with or without accelerants, inhibitors or proprietary solutions capable of producing parts that pass the specified test requirements
Citric 1: 4-10 w% Citric Acid, 140-160F, 4 Mins minimum
Citric 2: 4-10 w% Citric Acid, 120-140F, 10 Mins minimum
Citric 3: 4-10 w% Citric Acid, 70-120F, 20 Mins minimum
Citric 4: Other combinations of temperature time and concentration of citric acid with or without chemicals to enhance cleaning, accelerants or inhibitors capable of producing parts that pass the specified test requirements.
柠檬酸5：温度时间和柠檬酸浓度的其他组合，有或没有化学品，以增强能够产生通过规定的测试要求的零件的清洁，促进剂或抑制剂。浸渍浴以控制在1.8-2.2的pH下
Five testing methods to validate passivation services are provided as follows:
实践A - 水浸渍试验
Practice B – High Humidity Test
Practice C – Salt Spray Test
Practice D – Copper Sulfate Test
实践E - 铁氰化物 - 硝酸试验
在附录中提供了推荐的硝酸钝化方法表，其将硝酸1至5种方法与特定的不锈钢合金等级相关联。在CITRIC 1到5方法的规范中没有提供这种参考。
Passivation of Stainless Steel to AMS 2700
AMS 2700涵盖了对硝酸和柠檬酸方法的钝化
Method 1 – Passivation in Nitric Acid (see types below)
方法2-柠檬酸（4-10W％柠檬酸，提供各种温度/时间比，提供额外的润湿剂和抑制剂）
可以为方法1指定以下类型：
Type 1 – Low temperature nitric acid with sodium dichromate (20-25v% nitric, 2-3w% sodium dichromate, 70-90F, 30 mins min)
2 - 中等温度硝酸配二色素钠（20-25V％硝酸，2-3W％二聚值钠，120-130F，20分钟）
Type 3 – High temperature nitric acid with sodium dichromate (20-25v% nitric, 2-3w% sodium dichromate, 145-155F, 10 mins min)
Type 4 – 40v% nitric acid for free machining steels (38-42v% nitric, 2-3w% sodium dichromate, 70-120F, 30 mins min)
5型 - 阳极，用于高碳马氏体钢（20-25V％硝酸，2-3W％二聚值钠，70-90F，2分钟，在3-5伏特的部分阳极）
Type 6 – Low temperature nitric acid (25-45v% nitric, 70-90F, 30 mins min)
Type 7 – Medium temperature nitric acid (20-25v% nitric, 120-140F, 20 mins min)
Type 8 – Medium temperature, high nitric acid concentration (45-55v% nitric, 120-130F, 30 mins min)
3.1.3 Method 2 – Passivation in Citric Acid
3.1.3.1 Bath Composition
零件应浸入4至10％柠檬酸的水溶液中，具有额外的润湿剂和抑制剂，如适用。
3.1.3.2.1 Temperature
Bath temperature shall be 70 to 160F (21 to 71C) with an immersion time of not less than 4 minutes for baths operating over 140F (60C), not less than 10 minutes for baths operating in the 120 to 140F (49 to 60C) range, not less than 20 minutes for baths operating in the range of 100 to 119F (38 to 48C) or not less than 30 minutes for baths operating below 100F (38C).
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- 4-10w% Citric Acid, 140-160F, 4 Mins Min
- 4-10w% Citric Acid, 120-140F, 10 Mins Minimum
- 4-10W％柠檬酸，100-119F，最小20分钟
- 4-10w% Citric Acid, 70-100F, 30 Mins Minimum
Where no type is specified, the processor may use any of the listed types that meet the requirements given within AMS 2700.
在AMS 2700中提供以下类别进行测试（如果没有定义类，则适用第2级）：
1类 - 未定义或根据客户指定的测试，每4.3.1试验计划
2类 - 测试应为每批零件
Class 3 – Frequency of testing shall be on a periodic basis
Class 4 – Frequency of testing defined by 4.3.4 sampling plan (testing previously defined by QQ-P-35)
Various corrosion resistance tests are defined within AMS 2700. However, it is noted that certain alloys such as high carbon alloys with 0.85% carbon or more (such as 440C) are exempt from various testing requirements due to false positives that can result. Parts shall meet one or more of the following tests:
- 湿度测试
- Water Immersion
- Copper Sulfate Test
- Salt Spray Test
Table 4 within AMS 2700 provides a comprehensive summary of both nitric and citric acid methods that can be applied as a function of alloy. This table is more comprehensive than those listed in either ASTM A967 or QQ-P-35.
Passivation of Stainless Steel to QQ-P-35
QQ-P-35 does not cover citric acid passivation services. Four active nitric acid passivation services are covered as follows (four inactive methods have been withdrawn):
类型我 - 撤回
II型 - 20-25 V％硝酸，2-2.5W％二聚值钠，120-130F，最小20分钟
Type III – Withdrawn
IV型 - 撤回
Type V – Withdrawn
Type VI – 25-45 v% Nitric, 70-90F, 30 Mins minimum
Type VII – 20-25 v% Nitric, 120-150F, 20 Mins minimum
Type VIII – 45-55 v% Nitric, 120-130F, 30 Mins minimum
Four testing methods to validate passivation services are provided as follows:
4.4.1.1 – Water Immersion Test
4.4.1.2 – High Humidity Test
4.4.2.1 – Salt Spray Test
4.4.2.2硫酸铜试验
A table of recommended nitric acid passivation services is provided in the Appendix that correlate Type II, VI, VII & VIII methods to the specific stainless steel alloy grade.
