| 规格 | ASME SB338，ASTM B338 | 年级 | GR7 |
|---|---|---|---|
| 类型 | 无缝/焊接 | 尺寸标准： | ASTM B16.10 & B16.19 & 定制 |
| 强光 | Titanium Alloy Heat Exchanger Tube， Condenser Ti Alloy Tube， UNS R52400 Ti Alloy Tube | ||
ASME SB338 GR7 UNS R52400 Ti Alloy Tube for Condenser Heat Exchanger
ASME SB338 is the standard specification for seamless and welded titanium and titanium alloy tubes or tubing which are intended for surface condensers， evaporators， and heat exchangers. It is identical with ASTM B338 except for some minor difference in product marking. There are 28 grades of titanium and titanium alloys for tubing purpose， among which Titanium Grade 2， Grade 7 and Grade 12 are most often seen in tubing applications.
钛合金 七年级 has outstanding corrosion resistance and useful strength at low density. A small addition of palladium has been made to this alloy for a substantial increase in corrosion resistance.
What is the titanium alloy?
Titanium alloy refers to a variety of alloy metals made of titanium and other metals. Titanium is an important structural metal developed in the 1950s， titanium alloy has high strength， good corrosion resistance and high heat resistance. In the 1950s to 1960s， it was mainly the development of high-temperature titanium alloys for aeroengines and structural titanium alloys for the body.
A number of corrosion-resistant titanium alloys were developed in the 1970s， and since the 1980s， corrosion-resistant titanium alloys and high-strength titanium alloys have been further developed. Titanium alloy is mainly used in the production of aircraft engine compressor components， followed by rockets， missiles and high-speed aircraft structural parts
History of titanium development
Titanium is an important structural metal developed in the 1950s， and titanium alloy is widely used in various fields because of its high strength， good corrosion resistance and high heat resistance. Many countries in the world have realized the importance of titanium alloy materials， have carried out research and development on it， and have been practical applications.
According to relevant statistics， in 2012， the amount of titanium used in China's chemical industry reached 25，000 tons， which was reduced from 2011. This is the first time since 2009 that China's chemical titanium market has experienced negative growth. In recent years， the chemical industry has been the largest user of titanium processing materials， and its proportion in the total consumption of titanium materials has been maintained at more than 50%， accounting for as high as 55% in 2011. However， with the economic downturn， the chemical industry will not only significantly reduce the number of new projects， but also face industrial restructuring， the new production capacity of some products is controlled， and backward production capacity will be phased out. Affected by this， the shrinkage of the amount of titanium processing materials has become natural. Prior to this， some industry insiders predicted that the amount of titanium used in the chemical industry would peak between 2013 and 2015. According to the current market performance， the weakness of the overall economy in 2012 May make the decline period of chemical titanium earlier.
GR7 的化学成分
| 要素 | 化学成分 % |
| 七年级 | |
| 氮，最大 | 0.03 |
| 碳，最大值 | 0.08 |
| 氢，最大值 | 0.015 |
| 铁，最大 | 0.30 |
| 氧气，最大值 | 0.25 |
| 铝质 | ... |
| 钒 | ... |
| 锡 | ... |
| 钌 | ... |
| 钯金 | 0.12-0.25 |
| 钼 | ... |
| 铬 | ... |
| 镍 | ... |
| 铌 | ... |
| Ziconium | ... |
| 硅 | ... |
| 残差，每个最大 | 0.1 |
| 残差，最大总数 | 0.4 |
| 钛 | 平衡 |
7 级钛管的机械性能
| 等级 | Gr7 钛合金 |
| 密度 | 0.163 磅/英寸3 |
| 拉伸强度 | 50 |
| 屈服强度（0.2%Offset） | 40/65 |
| 伸长率 | 20% |
7 级钛管 物理特性
| Beta Transus (F ± 25) | 1675 | ||||
| 热膨胀系数（10-6 英寸/英寸/华氏度） | 32-212 | 4.8 | |||
| 32-600 | 5.1 | ||||
| 32-1000 | 5.4 | ||||
| 32-1200 | 5.6 | ||||
| 32-1500 | 5.6 | ||||
| 密度（磅/立方英寸） | 0.163 | ||||
| 熔点，约（华氏） | 3020 | ||||
| 室温下的电阻率（微欧厘米） | 56 | ||||
| Modulus Elasticity – Tension (106 psi) | 14.9 | ||||
| Modulus Elasticity – Torsion (106 psi) | 6.5 | ||||
| 导热性 （英制热量/小时/平方英尺/华氏度/英尺） | 室温下为 9.5 | ||||
| 室温下的比热（Btu/lb./F）。 | 0.124 | ||||
| 焊接性 | 良好 | ||||
| 退火温度 (F) | 全部 | 1300°/30 Min. – 2 Hrs，; Air Cool | |||
| 缓解压力 | 1000-1100°/30 分钟；空气冷却 | ||||
| 锻造* 温度 (F) | 封锁 | 1600-1700° | |||
| 加工 | 1500-1600° | ||||
| 现有磨机产品 | 管材，油管 | ||||
| 典型应用 | 用于化工行业中介质具有轻度还原性的耐腐蚀领域 或在氧化性和还原性之间变化。 | ||||
GR7 材料当量
| 标准 | WERKSTOFF NR. | UNS |
| 7 级钛 | 3.7235 | R52400 |
应用
-氯化系统
-烟气洗涤器
-Outlet ducting and stack liners for power plants， pulp and paper bleach plants， sulfur dioxide scrubbers， and weld overlay of less corrosion resistant metals
-制酸和酸洗系统
-Pharmaceutical industries use alloy fittings and tubing to avoid contamination caused by corrosion related failures
-玻璃纸制造
-氯化系统
