1, carbon steel

碳素钢适用于非腐蚀性介质，在某些特定的条件下，例如某些有腐蚀性的介质在一定范围内的温度浓度条件下也可采用碳素钢。

Carbon steels are suitable for non corrosive media, and carbon steels can be used under certain conditions, such as some corrosive media, in a certain range of temperature concentration.

碳素钢的适用温度范围：-29~425℃。中石化标准SH 3064《石油化工钢制通用阀门选用、检验及验收》规定碳素钢制阀门的适用温度范围为-20~425℃，其下限定为-20℃的依据是GB 150《钢制压力容器》。但当以WCB、WCC这两种钢作阀体、阀盖、闸板（阀瓣）、支架时，这两种钢的适用温度下限为-29℃。

Applicable temperature range of carbon steel: -29~425 C. The standard of Sinopec SH 3064 "steel valves used in petrochemical industry selection, inspection and acceptance of" the provisions applicable temperature range for carbon steel valves is -20~425 Deg. C, which is defined as -20 C is based on the GB 150 "steel pressure vessel". However, when the two steel WCB and WCC are used as valve body, valve cover, gate valve (valve clack) and bracket, the applicable temperature limit of the two steels is -29 degrees centigrade.

2、不锈钢

2, stainless steel

2.1奥氏体不锈钢

2.1 austenitic stainless steel

阀门中常用的不锈钢是奥氏体不锈钢，适用温度范围很广，低温可用于-296℃（液氦），高温可达到816℃，常用的温度范围为-196℃（液氮）至700℃。

The commonly used stainless steel valves in austenitic stainless steel, suitable temperature range is very wide, can be used for low temperature -296 C (liquid helium), high temperature can reach 816 DEG C, the temperature range of commonly used -196 DEG C to 700 DEG C (Ye Dan).

奥氏体不锈钢具有良好的耐腐蚀性、高温抗氧化性和耐低温性能。因此，奥氏体不锈钢广泛用于制作耐腐蚀阀门、高温阀门和低温阀门。

Austenitic stainless steel has good corrosion resistance, high temperature oxidation resistance and low temperature resistance. Therefore, austenitic stainless steel is widely used to make corrosion-resistant valves, high temperature valves and cryogenic valves.

奥氏体不锈钢的耐腐蚀性是相对的，不是什么样的腐蚀介质它都能承受。金属的腐蚀现象或所谓的耐腐蚀性是根据腐蚀性介质的种类、浓度、温度、压力、流速等环境条件，以及金属本身的性质，即含有成分、加工性、热处理等诸因素的差异而分别有不同的腐蚀状态和腐蚀速度。例如不锈钢具有优良的耐腐蚀性能，可是因为腐蚀环境或使用条件的不同，也可能发生意想不到的腐蚀破坏事故。因此，应充分地了解腐蚀介质和耐腐蚀材料，才能选择合适的耐腐蚀材料。

Austenitic stainless steel corrosion resistance is relative, not what kind of corrosive medium, it can withstand. The phenomenon of corrosion or corrosion resistance is based on the type and the concentration of corrosive media, temperature, pressure, flow rate and other environmental conditions, and the nature of the metal itself, which contains the factors of differences in composition, processing, heat treatment and corrosion and corrosion rate were different. For example, stainless steel has excellent corrosion resistance, but because of the corrosive environment or the use of different conditions, but also may occur unexpected corrosion damage accident. Therefore, it is necessary to fully understand the corrosion medium and corrosion resistant material, in order to select the appropriate corrosion resistant material.

2.2马氏体不锈钢

2.2 martensitic stainless steel

马氏体不锈钢是一种铬不锈钢，其金相组织为马氏体，可通过热处理进行强化，具有良好的力学性能和高温抗氧化性。该钢种在大气、水和弱腐蚀介质如加盐水溶液、稀硝酸及某些浓度不高的有机酸，在温度不高的情况下均有良好的耐腐蚀性。但该钢种不耐强酸如硫酸、盐酸、浓硝酸等的腐蚀，常用于水、蒸汽、油品等弱腐蚀性介质。由于铬不锈钢可通过热处理强化，因此为了避免强度过高产生脆性，应采用正确的热处理工艺。如ASTM A 217 CA15规定其最低回火温度为595℃。

Martensitic stainless steel is a kind of chromium stainless steel. Its microstructure is martensite, which can be strengthened by heat treatment. It has good mechanical properties and high temperature oxidation resistance. The steel has good corrosion resistance in the atmosphere, water and weak corrosive media such as saline solution, dilute nitric acid and some organic acids with low concentration. But the steel is not resistant to strong acid, such as sulfuric acid, hydrochloric acid, concentrated nitric acid corrosion, often used in water, steam, oil and other weak corrosive medium. Since chromium stainless steel can be strengthened by heat treatment, the correct heat treatment process should be adopted to avoid brittleness due to excessive strength. For example, ASTM A 217 CA15 specifies that the minimum tempering temperature is 595 C.

常用马氏体不锈钢铸件、锻件材料见表1-5。

The commonly used martensitic stainless steel castings and forgings are shown in table 1-5.

2.3奥氏体——铁素体双相不锈钢

2.3 austenite ferrite duplex stainless steel

双相不锈钢耐应力腐蚀破坏性好，适用于含氯离子环境的腐蚀，并具有较高的强度，常用于化肥、炼油、海上采油、海水淡化等工况条件。

Duplex stainless steel has good corrosion resistance and corrosion resistance, which is suitable for the corrosion of chloride ion environment, and has high strength. It is commonly used in chemical fertilizer, refining, offshore oil production, desalination and other working conditions.

目前制造阀门主体（承压件）的双相不锈钢材料大多采用美国材料，常用的奥氏体—铁素体双相不锈钢铸件、锻件材料见表1-6。

At present, most of the duplex stainless steels that make the main body of the valve (pressure parts) are made of American materials, and the commonly used austenitic ferrite duplex stainless steel castings and forgings are shown in table 1-6.

3、铬—钼钢和铬—钼—钒钢

3, chromium - molybdenum steel and chromium - molybdenum - vanadium steel

铬—钼钢和铬—钼—钒钢主要用在高温、高压的场合，要求钢在高温下具有较好的抗蠕变强度和抗高温氧化性，适用温度-29~650℃，主要用于火力发电的高温、高压蒸汽，炼油企业的石油裂解、催化裂化、加氢等含有硫化物、氢腐蚀的石油介质。例如催化系统采用5Cr—0.5Mo钢，加氢系统温度较低的采用1Cr—0.5Mo钢，温度较高的加氢裂化、加氢脱硫煤液化等装置中采用2.25Cr—1Mo钢。

Chromium - molybdenum steel and chromium - molybdenum - vanadium steel is mainly used in high temperature and high pressure situations, requirements of steel has better creep strength and oxidation resistance at high temperature, suitable temperature is -29~650 DEG C, mainly used in high temperature and high pressure steam power, oil refining enterprises medium oil cracking and catalytic cracking, hydrogenation, etc. containing sulfide, hydrogen corrosion. For example, 5Cr 0.5Mo steel is used in catalytic system, 1Cr 0.5Mo steel is used at lower temperature of hydrogenation system, 2.25Cr 1Mo steel is used in high temperature hydrocracking, hydrodesulfurization, coal liquefaction and other devices.

在Cr—Mo钢中需要说明的是ZG1Cr5Mo，过去称铸钢铬5钼（ZGCr5Mo）用该钢制作的阀门习惯上都称铬5钼阀，可是铸钢铬5钼这个牌号在1999年以前即无国家标准也无专业标准，长期以来各制造厂均参照前苏联标准来制订自己的工厂标准其牌号为ZGCr5Mo，其含碳量为0.15~0.25%，因此实际牌号应定为ZG2Cr5Mo。中石化在制订SH 3064-94《石油化工钢制通用阀门选用、检验及验收》标准时参照JIS G 5151中的SCPH61、BS 3100中的B5、ASTM A 217中的C5及我国GB/T 1221中的1Cr5Mo的化学成分将这种材料定为ZG1Cr5Mo，但同样只有牌号并无相关标准规定它的化学成分、力学性能、热处理规范等。70年代末引进装置中这类阀门的材料为ASTM A 217 C5，从化学成分上看相当铸钢1铬5钼，故建议用ASTM A 217 C5来制造这类阀门，一直到1999年在制订JB/T 9625《锅炉管道附件承压铸钢件 技术条件》时才将ZG1Cr5Mo纳入该标准中。

In Cr - Mo steel that is ZG1Cr5Mo, said the past 5 chromium molybdenum steel (ZGCr5Mo) with the steel valves used are called CR 5 mo cast steel valves, but the grade of Cr 5 mo before 1999 that no national standards nor professional standards, long-term since the factory according to the former Soviet Union the standard to set their own factory standard grades for the ZGCr5Mo, the carbon content is 0.15~0.25%, so the actual number should be ZG2Cr5Mo. Sinopec in the chemical composition of the formulation of SH 3064-94 "steel valves used in petrochemical industry selection, inspection and acceptance standard" when referring to JIS G 5151 SCPH61, BS 3100 B5, ASTM A 217 in C5 and China's GB/T 1221 1Cr5Mo in this material is ZG1Cr5Mo, but also have no brand relevant provisions of the standard of its chemical composition, mechanical properties, heat treatment specification etc.. At the end of 70s the introduction of this type of valve device made of ASTM A 217 C5, 5 mo 1 chromium cast steel is from the chemical composition, so it is recommended to use ASTM A 217 C5 to create this type of valve, until 1999, in the development of the JB/T 9625 "boiler pipe accessories bearing cast steel technical conditions" is included in the ZG1Cr5Mo standard.

ZG1Cr5Mo称5Cr—0.5Mo钢，这种钢具有良好的抗石油裂化过程介质腐蚀的性能，对含有硫化物的热石油介质耐蚀性良好，具有抗氢腐蚀的能力，并有良好的热强性。

ZG1Cr5Mo 5Cr - 0.5Mo steel, medium corrosion resistance property of this steel has good petroleum cracking process, the corrosion resistance of hot oil medium containing sulfide, good anti hydrogen corrosion, and has good heat resistance.

ZG1Cr5Mo制造工艺性较差，易产生铸造裂纹，焊接时热影响区会出现马氏体组织而产生明显的脆化，所以要制订正确的焊接工艺，焊前需进行预热，焊后需进行热处理，一般预热温度300~400℃，焊后热处理温度740~760℃。

The ZG1Cr5Mo manufacturing process is poor, easy to produce casting crack, welding heat affected zone will appear martensite embrittlement caused obvious, so to make the correct welding process, welding before preheating, postweld heat treatment should be carried out, the general preheating temperature of 300~400 DEG C, postweld heat treatment temperature 740~760.

4、低温钢

4, low temperature steel

一般低温指小于-29～-196℃范围内，小于-196～-269℃为超低温范围。石化企业规定低于-20℃就算低温。一般碳素钢、低合金钢、铁素体钢在低温下韧性急剧下降，脆性上

Generally, low temperature refers to less than -29 ~ -196 centigrade range, less than -196 ~ -269 degrees centigrade is ultra low temperature range. Petrochemical enterprises lower than -20 degrees even low temperature. The toughness of general carbon steel, low alloy steel and ferritic steel decreases sharply at low temperature