ASTM A350 specification covers several grades of carbon and low alloy steel forged or ring-rolled flanges, forged fittings and valves for low-temperature service. The steel specimens shall be melt processed using open-hearth, basic oxygen, electric furnace or vacuum-induction melting. A sufficient discard shall be made to secure freedom from injurious piping and undue segregation. The materials shall be forged and shall undergo heat treatment such as normalizing, tempering, quenching and precipitation heat treatment. Heat analysis and product analysis shall be performed wherein the steel materials shall conform to the required chemical compositions of carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, copper, columbium, vanadium, and nitrogen. The materials shall also undergo tension tests and shall conform to the required values of tensile strength, yield strength and elongation. Impact tests shall also be performed and the steel materials shall conform to the required values of minimum impact energy, temperature, and minimum equivalent absorbed energy. Hardness and hydrostatic tests shall also be performed.

ASTM A350規(guī)范涵蓋了用于低溫環(huán)境的幾種等級的碳鋼和低合金鋼鍛造或環(huán)軋法蘭、鍛造配件和閥門。鋼試樣應(yīng)使用平爐、堿性氧氣、電爐或真空感應(yīng)熔煉進(jìn)行熔融處理。應(yīng)進(jìn)行充分的丟棄，以確保沒有有害的管道和不當(dāng)?shù)母綦x。材料應(yīng)鍛造，并應(yīng)進(jìn)行正火、回火、淬火和沉淀熱處理等熱處理。應(yīng)進(jìn)行熱分析和產(chǎn)品分析，其中鋼材應(yīng)符合碳、錳、磷、硫、硅、鎳、鉻、鉬、銅、鈮、釩和氮的所需化學(xué)成分。材料還應(yīng)進(jìn)行拉伸試驗(yàn)，并應(yīng)符合抗拉強(qiáng)度、屈服強(qiáng)度和伸長率的要求值。還應(yīng)進(jìn)行沖擊試驗(yàn)，鋼材應(yīng)符合最小沖擊能量、溫度和最小等效吸收能量的要求值。還應(yīng)進(jìn)行硬度和靜水壓試驗(yàn)。

ASTM A350 (ASME SA350) is the standard specification for carbon steel and low alloy steel forged flanges and flanged fittings for low temperature services.

Common use grade is ASTM A350 LF2 Class 1, corresponding material for piping in ASTM A333 Grade 6 and pipe fittings in ASTM A420 WPL6. With yield strength minimum 240 Mpa, and tensile strength in 480 Mpa to 655 Mpa, impact test temperature at -45℃.

ASTM A350（ASME SA350）是低溫環(huán)境下碳鋼和低合金鋼鍛造法蘭和法蘭配件的標(biāo)準(zhǔn)規(guī)范。

常用等級為ASTM A350 LF2 1級，相應(yīng)的管道材料為ASTM A333 6級，管件材料為ASTM A420 WPL6。屈服強(qiáng)度最低為240 Mpa，抗拉強(qiáng)度為480 Mpa至655 Mpa，沖擊試驗(yàn)溫度為-45℃。

Scope

ASTM A350 covers several grades of carbon and low-alloy steel forged or ring-rolled flanges, forged fittings and valves intended primarily for low-temperature service and requiring notch toughness testing. They are made to specified dimensions, or to dimensional standards, such as the ASME and API Specifications referenced in Section 2. Although this specification covers some piping components machined from rolled bar and seamless tubular materials, it does not cover raw material produced in these product forms.

Product furnished in ASTM A350/ ASME SA350 shall conform to the requirements of Specification A961/A961M, including any supplementary requirements that are indicated in the purchase order. Failure to comply with A961/A961M will be considered nonconformance with A350. And in case of conflict between ASTM A350 and A961/A961M, this specification shall prevail.

ASTM A350涵蓋了幾種等級的碳鋼和低合金鋼鍛造或環(huán)軋法蘭、鍛造配件和閥門，主要用于低溫環(huán)境，需要進(jìn)行缺口韌性測試。它們是按照規(guī)定的尺寸或尺寸標(biāo)準(zhǔn)制作的，如第2節(jié)中引用的ASME和API規(guī)范。雖然本規(guī)范涵蓋了一些由軋制棒材和無縫管材加工而成的管道部件，但不包括以這些產(chǎn)品形式生產(chǎn)的原材料。

ASTM A350/ASME SA350中提供的產(chǎn)品應(yīng)符合規(guī)范A961/A961M的要求，包括采購訂單中指出的任何補(bǔ)充要求。不符合A961/A961M將被視為不符合A350。如果ASTM A350和A961/A961M之間存在沖突，應(yīng)以本規(guī)范為準(zhǔn)。

ASTM A350 Chemical composition requirements

*1. When vacuum carbon-deoxidation is required, the silicon content shall be 0.12% maximum.
*2. For grades LF1, LF2 & LF6, the sum of Cu, Ni, Cr, V and Mo shall not exceed 1.00 % on heat analysis.
*3. For all grades except grade LF787, the sum of Cr and Mo shall not exceed 0.32 % on heat analysis.
*4. For grades LF1 & LF2, the limit for Cb may be increased up to 0.05 % on heat analysis and 0.06 % on product analysis.
*5. The carbon equivalent C.E = [C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15] shall not exceed 0.45%.

*1.當(dāng)需要真空碳脫氧時，硅含量最大為0.12%。

*2.對于LF1、LF2和LF6級，熱分析中Cu、Ni、Cr、V和Mo的總和不得超過1.00%。

*3.對于除LF787以外的所有牌號，熱分析中Cr和Mo的總和不得超過0.32%。

*4.對于LF1和LF2級，Cb的限值在熱分析中可提高到0.05%，在產(chǎn)品分析中可增加到0.06%。

*5.碳當(dāng)量C.E=[C+Mn/6+（Cr+Mo+V）/5+（Ni+Cu）/15]不得超過0.45%。

ASTM A350 mechanical properties

*1. The elongation values are on the basis of standard round specimen, or small proportional specimen, min % in 4D gauge length.
*2. The yield strength shall be determined by either the 0.2 % offset method or the 0.5 % extension under load method.

*1.伸長率值基于標(biāo)準(zhǔn)圓形試樣或小比例試樣，4D標(biāo)距長度中的最小百分比。

*2.屈服強(qiáng)度應(yīng)通過0.2%偏移法或0.5%負(fù)載延伸法確定。

Mechanical Properties

Tension Tests Requirements—The material shall conform to requirements for tensile properties in below table.

Heat Analysis and Product Analysis

A chemical heat analysis and product analysis in accordance with Specification A961/A961M shall be made and conform to the requirements as to chemical composition prescribed in this table. Leaded steels shall not be permitted. Product analysis

Heat Treatment & Welding Process

As specified by ASTM A350, after hot working and before reheating for heat treatment, the forging shall be allowed to cool substantially below the transformation range. Forgings of grades other than Grade LF787 shall be furnished in the normalized, or normalized and tempered, or quenched and tempered condition. All quenched forgings shall be then tempered at 1100 °F [590 °C], minimum, holding at temperature a minimum of 30 min/in. [30 min/25 mm] of maximum thickness, but in no case less than 30 min. Grade LF787 forgings shall be furnished in either the normalized-and-precipitation heat treated condition or in the quenched-and-precipitation heat treated condition.

For Grade LF1 and LF2 forgings, the weld metal shall be deposited using carbon steel electrodes E 7015, E 7016, or E 7018, complying with AWS A 5.1. For Grade LF2 forgings, the weld metal shall be deposited using low-alloy steel electrodes E 7015-A1; E 7016-A1, or E 7018-A1 complying with AWS 5.5; for Grade LF3 forgings, the weld metal shall be deposited using low-alloy steel electrodes E 8016-C2 or E 8018-C2 complying with AWS A 5.5; for Grades LF5, LF9, and LF787 forgings, the weld metal shall be deposited using low-alloy steel electrodes E 8016-C1 or E 8018-C1 complying withAWS A 5.5. For Grade LF6, the electrodes shall be low-hydrogen, E-XX15, E-XX16, or E-XX18 complying with AWS A 5.1 or A 5.5, as applicable.

機(jī)械性能

拉伸試驗(yàn)要求——材料應(yīng)符合下表中的拉伸性能要求。

熱分析和產(chǎn)品分析

應(yīng)按照規(guī)范A961/A961M進(jìn)行化學(xué)熱分析和產(chǎn)品分析，并符合本表規(guī)定的化學(xué)成分要求。不允許使用含鉛鋼。產(chǎn)品分析

熱處理和焊接工藝

根據(jù)ASTM A350的規(guī)定，在熱加工后和重新加熱進(jìn)行熱處理之前，應(yīng)允許鍛件冷卻到相變范圍以下。LF787級以外的鍛件應(yīng)在正火、正火和回火或淬火和回火狀態(tài)下提供。然后，所有淬火鍛件應(yīng)在最低1100°F[590°C]的溫度下回火，保持最小30分鐘/英寸[30分鐘/25毫米]的最大厚度，但在任何情況下不得低于30分鐘。LF787級鍛件應(yīng)在正火和沉淀熱處理?xiàng)l件下或淬火和沉淀熱處理?xiàng)l件下提供。

對于LF1和LF2級鍛件，應(yīng)使用符合AWS A 5.1的碳鋼焊條E 7015、E 7016或E 7018沉積焊接金屬。對于LF2級鍛件，應(yīng)使用低合金鋼焊條E 7015-A1沉積焊縫金屬；符合AWS 5.5的E 7016-A1或E 7018-A1；對于LF3級鍛件，應(yīng)使用符合AWS A 5.5的低合金鋼焊條E 8016-C2或E 8018-C2沉積焊接金屬；對于LF5、LF9和LF787級鍛件，應(yīng)使用符合AWS A 5.5的低合金鋼焊條E 8016-C1或E 8018-C1沉積焊接金屬。對于LF6級，電極應(yīng)為符合AWS A 5.1或A 5.5（如適用）的低氫、E-XX15、E-XX16或E-XX18。

The dimensional standards for ASTM A350 forgings

Referenced Documents

ASTM Standards:

• A788/A788M Specification for Steel Forgings, General Requirements鋼鍛件規(guī)范，一般要求
• A961/A961M Specification for Common Requirements for Steel Flanges, Forged Fittings, Valves, and Parts for Piping Applications管道用鋼法蘭、鍛造配件、閥門和零件的通用要求規(guī)范

ASME Standards:

• B 16.5 Steel Pipe Flanges and Flanged Fittings鋼管法蘭和法蘭配件
• B 16.9 Factory-Made Wrought Steel Butt-Welding Fittings工廠制造的鍛鋼對接焊接配件
• B 16.10 Face-to-Face and End-to-End Dimensions of Ferrous Valves鐵質(zhì)閥門的面對面和端到端尺寸
• B 16.11 Forged Steel Fittings, Socket-Welding and Threaded承插焊和螺紋鍛鋼配件
• B 16.30 Unfired Pressure Vessel Flange Dimensions非受火壓力容器法蘭尺寸
• B 16.34 Valves-Flanged, Threaded, and Welding End法蘭、螺紋和焊接端的閥門
• B 16.47 Large Diameter Steel Flanges大直徑鋼法蘭
• ASME Boiler and Pressure Vessel Code鍋爐和壓力容器規(guī)范

AWS Standards:

• A 5.1 Mild Steel Covered Arc-Welding Electrodes低碳鋼焊條
• A 5.5 Low-Alloy Steel Covered Arc-Welding Electrodes低合金鋼焊條

API Standards:API標(biāo)準(zhǔn)

• 600 Steel Gate Valves with Flanged or Butt-Welding Ends法蘭或?qū)付虽撝崎l閥
• 602 Compact Design Carbon Steel Gate Valves for Refinery Use煉油廠用緊湊型碳鋼閘閥
• 605 Large Diameter Carbon Steel Flanges大直徑碳鋼法蘭

Manufacture – Melting and Forging制造-熔化和鍛造

Melting Process – The steel shall be produced by any of the following primary processes: open-hearth, basic oxygen, electric-furnace, or vacuum-induction melting (VIM). The primary melting may incorporate separate degassing or refining, and may be followed by secondary melting using electroslag remelting (ESR), or vacuum-arc remelting (VAR).

Discard – A sufficient discard shall be made to secure freedom from injurious piping and undue segregation.

Forging Process

Material for forgings shall consist of ingots, or forged, rolled, or strand cast blooms, billets, slabs, or bars.

制造-熔化和鍛造

熔煉工藝——鋼材應(yīng)通過以下任何一種主要工藝生產(chǎn)：平爐、堿性氧氣、電爐或真空感應(yīng)熔煉（VIM）。一次熔化可以包括單獨(dú)的脫氣或精煉，然后可以使用電渣重熔（ESR）或真空電弧重熔（VAR）進(jìn)行二次熔化。

丟棄——應(yīng)進(jìn)行充分的丟棄，以確保沒有有害的管道和不當(dāng)?shù)母綦x。

鍛造工藝

鍛件材料應(yīng)由鑄錠、鍛造、軋制或鑄坯、鋼坯、板坯或棒材組成。

Heat Treatment熱處理

After hot working and before reheating for heat treatment, the forging shall be allowed to cool substantially below the transformation range.

Forgings grades except Grade LF787, should be heat treated in normalized, or normalized and tempered, or quenched and tempered. By manufacturer’s option, material that performed in quenched and tempered could be normalized prior to the austenitize/quenched operation.

No limitation on size is intended beyond the ability of the manufacturer to obtain the specified requirements. However, Class 3 of Grade LF787 is only available in the quenched-and-precipitation heat treated condition.

熱加工后，在重新加熱進(jìn)行熱處理之前，應(yīng)允許鍛件冷卻到相變范圍以下。

除LF787級外的鍛件等級應(yīng)進(jìn)行正火、正火和回火或淬火和回火熱處理。根據(jù)制造商的選擇，在奧氏體化/淬火操作之前，可以對淬火和回火的材料進(jìn)行正火處理。

制造商獲得規(guī)定要求的能力之外，不打算對尺寸進(jìn)行任何限制。然而，LF787級的3級僅在淬火和沉淀熱處理?xiàng)l件下可用。

Hydro-static Test水壓試驗(yàn)

Forgings manufactured under ASTM A350/ ASME SA350 shall be performed with a hydro-static test compatible with the rating of the finished item. Such tests shall be conducted by the manufacturer only when Supplementary Requirement S57 of Specification A961/A961M is specified.

根據(jù)ASTM A350/ASME SA350制造的鍛件應(yīng)進(jìn)行與成品額定值兼容的靜水壓試驗(yàn)。只有在規(guī)定了規(guī)范A961/A961M的補(bǔ)充要求S57時，制造商才能進(jìn)行此類測試。