技術交流

1.2水處理不足的后果

 Consequences of inadequate water treatment

  對于滅菌蒸汽的給水，不完全或不充分的水處理的后果，有時可以在滅菌后立即在各個系統(tǒng)位置以視覺進行識別。因此，定期測試水質尤為重要。

     The consequences of incomplete or inade- quate water treatment in the case of feed water for sterilization steam can thus sometimes be visually recognised in various system locations immediately following sterilization. For this reason, it is particularly important to regularly test the water quality.

圖4：鹽殘留物   （Salt residues ）

2.不銹鋼-材料科學的簡短課程

Stainless steel – a brief lesson in materials science

    除主要的合金元素鐵（鐵含量通常為>50%)外，非腐蝕(耐腐蝕）鐵基不銹鋼合金還含有來自添加各種合金元素，如鉻、鎳、錳，在某些情況下，還有鉬等，出于以下目的：

?以獲得所需的性能特性（例如，耐腐蝕性）

?以確保所需的工作性能

?提供特定的物理性能，如強度和硬度

    In addition to the main alloying element iron (Fe content normally > 50%), non-corroding (rust-resistant) iron-based stainless steel alloys also contain additives from various alloying elements such as chromium, nickel, manganese and, in some cases, molybdenum, etc. for the following purposes:

? To obtain the desired performance characteristics (for example, corrosion-resistance) 

? To ensure the desired working properties 

? To provide specific physical properties，such as strength and hardness

  本領域的技術文獻描述了大量可用的鐵基不銹鋼合金，依據DINEN標準（如10020、10027-1和-2、10028和10088-1、-2和-3）規(guī)定的合金成分中的不同合金元素。

   The technical literature in this field describes a vast number of available iron-based stainless steel alloys along with the different alloying elements in the alloy composition specified by DIN EN standards such as 10020, 10027-1 and -2, 10028, and 10088-1, -2 and -3.

  術語“不銹鋼合金”將在下文中使用，一般指所有不受腐蝕的不銹鋼，如1.4301、1.4404和其他類似的鋼。一般來說，要區(qū)分奧氏體、鐵素體、馬氏體和鐵馬氏體雙相合金。在于他們不同等級的耐腐蝕性能。

    The term 'stainless steel alloy' will be used throughout the text below to generally denote all non-corroding stainless steel such as 1.4301, 1.4404 and other similar steels. Generally, a distinction is made between austenitic, ferritic, martensitic and ferriticmartensitic duplex alloys.

The alloys are distinguished, among other things, by their different levels of corrosion resistance.

  在醫(yī)療和生物醫(yī)藥領域，不同類型的不銹鋼合金的應用根據的是特定目的。例如，由于涉及到特殊的硬度要求，大多數(shù)外科手術和牙科器械都是由馬氏體不銹鋼合金制成的。

    In the medical and pharmaceutical fields, dif- ferent types of stainless steel alloys are used depending on the specific purpose. For example, because of the special hardness requirements involved, most surgical and dental instruments are made from martensitic stainless steel alloys.

  然而，與奧氏體不銹鋼合金相比，馬氏體合金在硬化過程中獲得了更高的硬度值，并且在進行正確的機械工作時，具有一致的銳度。

    However, compared to austenitic stainless steel alloys, martensitic alloys attain much higher hardness values following the hardening process and, when subjected to the right mechanical working, a consistent sharpness.

  例如，在使用期間受到顯著機械壓力載荷下的植入物和設備部件優(yōu)選用奧氏體不銹鋼范圍內的不同牌號來制造。從生產的角度來看，這些合金的加工成本通常比鐵素體或馬氏體不銹鋼合金更便宜。

    Implants and device components that are exposed to significant mechanical pressure loads during use, for example, are preferably manufactured from different variants across the range of available austenitic stainless steels. From a production standpoint, these alloys are usually less expensive to process than ferritic or martensitic stainless steel alloys.

  毫無疑問，全面的、同性能的、堅固附著的、無阻礙的不銹鋼合金的典型且可能是最重要的性能特征是其耐腐蝕性。這種化學性質可以歸因于富含鉻氧化物的相應鈍化層的存在。

    Without a doubt, the typical and probably most important performance characteristic of stainless steel alloys is their corrosion resistance. This chemical property can be attributed to the unimpeded presence of a full-area, homogeneous and firmly adhering passive layer that is rich in chromium oxide.

  從化學和熱力學的角度來看，鈍化層對于腐蝕保護和不銹鋼表面更大的化學惰性是負有責任的。

    From a chemical and thermodynamic perspective, the passive layer is what is responsible for corrosion-protected and chemically largely inert stainless steel surfaces.

  化學元素鉻對鈍化層的形成至關重要，因為鉻(III)氧化物氧化二鉻除了鐵和氧化鐵之外，是這個完整的鈍化層的主要組成部分。

    The chemical element chromium is critical to the formation of the passive layer, since chromium(III) oxide (Cr2O3) is the main constituent of an intact passive layer aside from Fe and Fe oxide.

  當元素鉻（作為不銹鋼表面的主要統(tǒng)計成分）與氧氣結合時，就會形成不銹鋼表面的保護性鈍化層，例如從空氣中，從含有物理溶解氧的水溶液中，或從其他提供氧的鈍化溶液中，并在不銹鋼表面形成一層始終富含氧化鉻的層。盡管這層的厚度只有13納米（相當于大約5-10個原子層)，但這一層能夠在金屬和周圍環(huán)境之間形成化學保護(惰性）屏障，同時允許電子而不允許離子通過，從而不斷地阻擋組件表面的電位腐蝕電流。

    The protective passive layer of a stainless steel surface forms when the element chromium (as a major statistical constituent of the stainless steel surface) combines with oxygen, e.g. from the air, from aqueous solutions with physically dissolved oxygen, or from other oxygen-providing passivation solutions, and creates on the stainless steel surface a layer that is consistently rich in chromium oxide. Despite an extremely low thickness of just 13 nm (equal to roughly 5– 10 atomic layers), this layer is capable of forming a chemically protective (inert) barrier between the metal and the surrounding environment whilst allowing electrons–but not ions—to pass, and thus constantly blocking potential corrosion currents at the component's surface.

圖5：一個完整的鈍化層[1]、[2]的模型描述（Model depiction of an intact passive layer [1], [2]）

  化學上，鈍化層主要由氧化鉻作為基質組成，包括鐵（Fe）、鐵氧化物（Fe）、鎳（Ni）、鎳氧化物（Ni）。對鈍化不銹鋼表面的俄歇分析和ESCA研究表明，Cr/Fe比>1，而基于根據合金內部成分，Cr/Fe比<0.3。

    Chemically, the passive layer is composed mainly of chromium oxide as a matrix with incorporations of iron (Fe) and iron (Fe) oxide and nickel (Ni) and nickel (Ni) oxide. Analytical AUGER and ESCA studies of passive stainless steel surfaces show Cr/Fe ratios > 1, whereas Cr/Fe ratios < 0.3 are usually found in the 'alloy interior' based on the alloy composition.

圖6：鈍化層厚度/鉻與鐵之比[5]（Passive layer thickness / Cr to Fe ratio [5]）

  不銹鋼合金的耐腐蝕材料性能通常是由于其能夠形成“富鉻-氧化物鈍化層”的結果，將組件的表面轉換為“鈍化”，抗腐蝕或極惰性的狀態(tài)。在每種獨立情況下，非腐蝕性不銹鋼合金的化學/熱力學鈍化屬性意味著，即使在主要腐蝕性的環(huán)境條件下，也可以避免材料的腐蝕（腐蝕）——每一種不銹鋼合金都具有不同的電位耐腐蝕性，特別是“更高等級或更高的合金含量”材料也能抵抗更嚴重的腐蝕攻擊，否則會導致更簡單的不銹鋼的腐蝕失效，另外——成功的鈍化需要不銹鋼表面也要經過預處理，以便完全能夠鈍化。

    The corrosion-resistant material behaviour of a stainless steel alloy is generally the result of its capability to form the 'chromium-oxiderich passive layer', which converts the component's surface into a 'passive',non-corroding or extremely inert state.In each individual case, the chemical/thermodynamic passivity of non-corroding stainless steel alloys means that material attack (corrosion) is avoided even under environmental conditions that are predominantly corrosive. To this, however, it must also be added that—each individual stainless steel alloy has a different potential corrosion resistance, and that 'higher grade or higher alloy' materials in particular are also resistant to more severe corrosion attacks that would otherwise cause corrosion failure in simpler stainless steel a lloys,and that—successful passivation requires, among other things, that the stainless steel surface in question also be pre-conditioned such that it is fully capable of being passivated.

來自：德國的錢伯斯工作組(德語縮寫：AKK)的手冊