在壓力容器設計中，一提到奧氏體不銹鋼的熱處理，人們總是說不。但需要注意的是GB150或ASME只是對焊后熱處理（PWHT）不作要求?；\統(tǒng)地說奧氏體不銹鋼不能進行熱處理，是不準確的。GB150要求奧氏體不銹鋼在經(jīng)過固溶處理后供貨，這就已經(jīng)是熱處理了。

ASM HANDBOOK VOLUMN4: HEATTREATING 第1682頁-第1703頁，摘錄如下：

一、傳統(tǒng)的奧氏體不銹鋼

Conventional austenitic cannot be hardenedby heat treatment but will harden as a result of cold working.

奧氏體不銹鋼無法通過熱處理強化，但可以通過冷加工變形強化。

These steels are usually purchased in an annealed orcold-worked state.

它們的供貨狀態(tài)通常是退火或冷加工

Following welding or thermal processing, a subsequent re-annealmay be required for optimum corrosion resistance, softness, and ductility.

在焊接或熱加工中，為了抗腐蝕性能、軟化及延展性，通常要求進行再退火。

During annealing, chromium carbides, which markedlydecrease resistance to intergranular corrosion, are dissolved.

在退火中，顯著損害抗晶間腐蝕能力的碳化鉻將會重新溶解。

Annealing temperatures, which vary somewhat with thecomposition of the steel（退火溫度與鋼材成分有關）, are given in Table 3 forwrought alloys（鍛造合金）and in Table 4 for thecorresponding cast alloys（鑄造合金）. Table 5 includescompositions and typical microstructures（金相組織） forselected austenitic corrosion-resistant cast steels

Because carbide precipitation can occur at temperaturesbetween 425 and 900 °C (800 and 1650 °F), it obviously is desirable that theannealing temperature should be safely above this limit.

在425至900°C會出現(xiàn)碳化物析出，退火溫度應高于這個范圍。

Moreover, because all carbides should be in solutionbefore cooling begins, and because the chromium carbide dissolves slowly, thehighest practical temperature consistent with limited grain growth is selected.This temperature is in the vicinity of 1095 °C (2000 °F).

碳化物應在冷卻前溶解，又因為碳化鉻溶解速度緩慢，實際的最高退火溫度通常在1095 °C左右。

Cooling from the annealing temperature must be rapid, butit must also be consistent with limitations of distortion. Wheneverconsiderations of distortion permit, water quenching is used, thus ensuringthat dissolved carbides remain in solution.

冷卻時，應當從退火溫度開始快速冷卻，若變形量允許可以采用水淬，以保證碳化物的固溶。

Because it precipitates carbides more rapidly, type 310invariably requires water quenching. Where practical considerations of distortionrule out such a fast cooling rate, cooling in an air blast is used.

因為碳化物析出較快，310不銹鋼通常要求水淬，考慮到變形量，可以采用空冷。

With some thin-section parts, even this intermediate rateof cooling（中等速率的冷卻） produces excessive distortion（超量變形）, andparts must be cooled in still air. If cooling in still air does not provide arate sufficient to prevent carbide precipitation（碳化鉻析出）,maximum corrosion resistance will not be obtained（無法獲得最大的抗腐蝕能力）. A solution to this dilemma is the use of a stabilized grade or thelow-carbon alloys.（應當改用穩(wěn)定化或超低碳不銹鋼。）

二、穩(wěn)定化不銹鋼

Stabilized austenitic alloys, namely types 321, 347, 348,and Carpenter 20Cb-3, contain controlled amounts of titanium or of niobium（含有一定量的鈦Ti和鈮Nb）, which render the steel nearly immune tointergranular precipitation of chromium carbide and its adverse effects oncorrosion resistance.（能夠防止晶間碳化鉻的析出，并抵抗晶間腐蝕）Nevertheless,these alloys may require annealing to relieve stresses, to increase softnessand ductility, or to provide additional stabilization.（若為了消除殘余應力，軟化金屬和增加延展性，或增強穩(wěn)定性，也可要求進行熱處理）

To obtain maximum softness and ductility, the stabilizedgrades are annealed at the temperatures shown in Table 3.

表3給出了穩(wěn)定化不銹鋼獲得最大軟化和延展性的退火溫度

Unlike the unstabilized grades, these steels do notrequire water quenching or other acceleration of cooling from the

annealing temperature to prevent subsequent intergranularcorrosion; air cooling is generally adequate.

穩(wěn)定化不銹鋼不要求水淬，或其他加速冷卻以防止晶間腐蝕的方法，空冷足矣。

When maximum corrosion resistance of the stabilized austeniticgrades is required, it may be necessary to employ a heat treatment known as astabilizing anneal.

如果要求有最大的抗腐蝕能力，通常要求進行穩(wěn)定化處理

The treatment consists of holding at 845 to 900 °C (1550to 1650 °F) for up to 5h, depending on section thickness.

熱處理制度取決于工件厚度，溫度范圍為845 to 900 °C，保溫最長5h。

It may be applied either prior to, or in the course of,fabrication, and it may be followed by short-time stress relieving at 705 °C(1300 °F) without danger of harmful carbide precipitation (see the section"Stress Relieving of Austenitic Stainless Steels" in this article).

穩(wěn)定化處理可以在制造加工之前或加工制造過程中進行，并可隨后在705°C進行短時的消除應力處理，若無需考慮碳化鉻的析出的危害。

Carpenter 20Cb-3 stainless steel is unlike theconventional stabilized austenitics (types 321, 347, and 348) because of its higheralloy content and improved corrosion resistance. This alloy normally isstabilized and annealed at 925 to 955 °C(1700 to 1750 °F).

與321,347及348等傳統(tǒng)的穩(wěn)定化不銹鋼不同，Carpenter合金 20Cb-3（即N08020）有更高的合金含量及更強抗腐蝕能力。20Cb-3合金在925~955°C這一更高的溫度范圍內穩(wěn)定化退火。

For special applications, the alloy can be annealed athigher temperatures (up to 1150 °C, or 2100 °F), but this is permissible onlyif the alloy will not be subject to welding or heating temperatures over 540 °C(1000 °F).

（這段不懂翻）

Certain restrictions on furnace atmosphere are mandatory（接下來是對熱處理爐膛氣氛的要求）.Furnace combustion（爐內燃燒） must be carefully controlledto eliminate carburizing （滲碳）or excessively oxidizing （氧）conditions. Because the properties of the stabilized steels arebased on their original carbon content, carbon absorption cannot be tolerated.（碳含量會影響穩(wěn)定化不銹鋼的性能） Excessively oxidizing conditions cause the formation of a scale thatis difficult to remove in subsequent descaling operations.（不利于隨后的除銹操作） Direct impingement of flame on the work must be prevented. （應避免火焰直接加熱）The sulfur content of the furnace atmosphere, particularly inoil-fired furnaces, must be kept low;（要控制燃油中的硫含量）naturalgas, not producer gas, should be used.（要用天然氣而不能用煤氣）

三、低碳奧氏體不銹鋼

Low-carbon austenitics are intermediate in tendency toprecipitate chromium carbides to the stabilized and unstabilized grades. Carboncontent (0.03% max) is low enough to reduce precipitation of intergranularcarbides. This characteristic of limited sensitization is of particular valuein welding, flame cutting, and other hot-working operations.

碳化鉻析出的傾向性介于穩(wěn)定化不銹鋼和非穩(wěn)定化不銹鋼之間。最多0.3%的碳含量能夠減少晶間碳化物的析出。這種特性對于防止焊接、火焰切割及其他熱加工中的敏化具有重要的意義。

They do not require the quenching treatment（淬火處理）that unstabilized grades requireto retain carbon in solid solution.（非穩(wěn)定化不銹鋼要求重新固碳）

Nevertheless, the low-carbon alloys are not satisfactory for long-timeservice in the sensitizing temperature range of 540 to 760 °C (1000 to 1400 °F)because they are not completely immune to the formation of carbides deleteriousto corrosion resistance.

低碳不銹鋼不宜在540 to 760 °C這一敏感的溫度區(qū)間長時間使用，因為它不能完全避免有損抗腐蝕性能的碳化物的形成。

Recommended annealing temperatures for the low-carbon alloys are given inTable 3.

表3給出了退火溫度。

The effects of sensitization and susceptibility to general corrosion varyamong the low-carbon alloys, depending on their chemical composition. Becausethey contain molybdenum, types 316L and 317L are susceptible to σ-phase formation as aresult of long-time exposure at 650 to 870 °C (1200 to 1600 °F).

化學成分影響抗腐蝕能力。長時間暴露于650 to 870 °C，鉬能促進σ相的形成。

However, the corrosion resistance of these grades can be improved byemploying a stabilizing treatment (ASTM A 262C), consisting of holding at 885°C (1625 °F) for 2 h, prior to stress relieving at 675 °C (1250 °F). Afterreceiving the stabilizing heat treatment, these alloys pass the copper-copper sulfate16% sulfuric acid test (ASTM A 262, Practice E) for freedom from intergranularcarbide precipitation.

在675°C消除應力處理之前，進行885 °C，2h保溫的熱處理，能夠提高抗腐蝕性能。（能夠通過ASTM A 262,方法E的晶間腐蝕試驗。）

四、高氮奧氏體不銹鋼

High-nitrogen austenitic stainless steels are heattreated in the same manner and are subject to the same problems (carbideprecipitation and distortion) as conventional austenitics. They cannot behardened by heat treatment but

will harden by cold working.

高氮奧氏體不銹鋼與傳統(tǒng)奧氏體不銹鋼一樣同樣有碳化物析出和變形的問題。熱處理無法強化，但冷加工會出現(xiàn)硬化。

High-nitrogen austenitics are annealed to ensure maximumcorrosion resistance, softness, and ductility. Rapid cooling is preferred.Annealing temperature ranges are listed in Table 3.

要求快冷。

五、高合金奧氏體不銹鋼

Highly alloyed austenitic stainless steels contain largeamounts of molybdenum to provide very good resistance

to chloride corrosion. （高鉬，抗氯化物腐蝕）They usually are producedwith low carbon to avoid sensitization （低碳，避免敏化）and maycontain copper for increased acid resistance（銅，抗酸腐蝕）.These alloys are austenitic in the mill-annealed condition but may form σ or δferrite phases under certain conditions of heat treatment or service. Thosephases may be detrimental to corrosion resistance and mechanical properties.

軋制退火時是奧氏體，但在特定的熱處理或使用過程中也會出現(xiàn)σ或δ鐵素體，這些相有損抗腐蝕性能和機械性能。

Annealing temperatures are confined to a narrow range toavoid σ-phase formation at lower temperature, or δ ferrite at highertemperature. 熱處理溫度選擇范圍有限，應采用較低溫度以避免σ相的形成，或采用較高溫度以避免δ鐵素體的形成。

Recommended annealing temperatures are given in Table 1.

Rapid cooling（快速冷卻）following annealing is usuallyadvisable, especially in heavy sections.

Stress-relief treatments may be used below the annealingtemperature range, but holding times should be held to a minimum to avoid ωphase and sensitization problems.

消除應力熱處理溫度應低于退火溫度，熱處理時間應考慮避免ω相的形成和敏化問題。

六、奧氏體不銹鋼的光亮退火（看不懂，略）