317L不锈钢

317L is a molybdenum bearing austenitic chromium nickel steel similar to type 316, except the alloy content in 317L is somewhat higher.

不锈钢317 L在温度升高时具有较高的拉伸力和蠕变强度。由于其出色的耐腐蚀性，它已用于处理化学工艺行业使用的许多化学物质。

它具有在特殊应用中具有晚餐腐蚀性的，需要将污染降至最低。317L的开发主要是为了更有效地抵抗硫酸化合物的攻击。霍弗（Howerver），其可靠的对抗腐蚀能力已大大扩大了其使用，现在正在用于许多其他工业应用。

317L的低碳含量可免疫在焊接后无法退火或需要减轻低温应力治疗的应用中，在晶间腐蚀中提供了免疫力。

Specifications - Stainless Steel 317L

317L (00Cr19Ni13Mo3, SUS317L) alloy is based on molybdenum and austenitic stainless steel. It is more resistant to chemical corrosion than normal chrome-nickel austenitic stainless steel, such as 304 alloys. In addition, compared with conventional stainless steel, 317L alloys have higher ductility, anti-stress corrosion, compressive strength and high temperature resistance. It is a low carbon grade or L rating, which has the ability to resist sensitization during welding and heat treatment.

ASTM: A312, A403, A182
ASME：SA312，SA403，SA182

Chemical Composition - Stainless Steel 317/317L

Grade	317	317L
UNS Designation	S31700	S31703
Carbon (C) Max.	0.08	0.035*
Manganese (Mn) Max.	2.00	2.00
Phosphorous (P) Max.	0.040	0.04
硫	0.03	0.03
Silicon (Si) Max.	1.00	1.00
Chromium (Cr)	18.0–20.0	18.0–20.0
镍（NI）	11.0–14.0	11.0–15.0
Molybdenum (Mo)	3.0–4.0	3.0–4.0
Nitrogen (N)	—	—
铁（铁）	Bal.	Bal.
Other Elements	—	—

Typical Mechanical Properties- Stainless Steel 317L

材料	Ultimate Tensile Strength (Mpa)	0.2％的屈服强度（MPA）	% Elongation in 2"	Rockwell B Hardness
合金317	515	205	35	95
合金317L	515	205	40	95
Minimum Mechanical Properties by ASTM A240 and ASME SA 240

Design Features - Stainless Steel 317L

具有合金含量的甲基化铬镍钢的钼含量略高于316年级。
Superior corrosion resistance in difficult environments.
Higher creep, stress-to-rupture and tensile strengths than other stainless steels.
Reduced intergranular precipitation of chromium carbides during welding and stress relieving as well as minimized possibility of corrosion failure from intergranular attack due to low carbon content.
Resistance to pitting and crevice corrosion making 317L a successful life-cost product in a variety of highly corrosive environments.

Typical Applications - Stainless Steel 317L

Flue gas desulfurization scrubber systems
Chemical and petro-chemical processing equipment
Pulp and paper plants
Food processing equipment
Textile equipment

Tensile Requirements - Stainless Steel 317L

Tensile Strength（KSI）：75
产量强度（KSI）：30

317L（1.4438）一般财产

合金317LMN and 317L are molybdenum-bearing austenitic stainless steel tube with greatly increased resistance to chemical attack as compared to the conventional chromium-nickel austenitic stainless steel pipe such as Alloy 304. In addition, 317LMN and 317L alloys offer higher creep, stress-to-rupture, and tensile strengths at elevated temperatures than conventional stainless steels. All are low carbon or "L" grades to provide resistance to sensitization during welding and other thermal processes.

The "M" and "N" designations indicate that the compositions contain increased levels of molybdenum and nitrogen respectively. The combination of molybdenum and nitrogen is particularly effective in enhancing resistance to pitting and crevice corrosion, especially in process streams containing acids, chlorides, and sulfur compounds at elevated temperatures. Nitrogen also serves to increase the strength of these alloys. Both alloys are intended for severe service conditions such as flue gas desulfurization (FGD) systems.

除了出色的耐腐蚀性和强度特性外，合金316、316L和317L CR-NI-MO合金还提供了极好的纤维性和外形能力，这是奥氏体不锈钢管的典型特征。

317L (1.4438) Heat Treatment

Annealing

奥氏体不锈钢管在磨坊退火状态中提供，准备使用。在制造过程中或之后，可能需要进行热处理以去除冷形成或溶解由热暴露导致的沉淀碳化物的作用。对于合金316和317L，溶液退火是通过在1900至2150°F（1040至1175°C）的温度范围内加热来完成的，然后取决于空气冷却或水淬火，具体取决于截面的厚度。在1500至800°F（816至427°C）范围内，冷却应足够快地快速，以避免重新沉淀碳化物并提供最佳的耐腐蚀性。在每种情况下，金属都应在不到三分钟的时间内将金属从退火温度冷却到黑热。

Forging

The recommended initial temperature range is 2100-2200°F (1150-1205°C) with a finishing range of 1700-1750°F (927-955°C).

Annealing

317LMN和合金317L不锈钢可以在1975-2150°F（1080-1175°C）的温度范围内退火，然后取决于厚度，然后进行空气冷却或水淬火。应在2100°F（1150°C）和2150°F（1175°C）之间退火。金属应在不到三分钟的时间内从退火温度（从红色/白色到黑色）冷却。

Hardenability

这些等级不能通过热处理能加固。
合金s 316 and 317L stainless steel tube cannot be hardened by heat treatment.

Is Grade 317 Stainless Steel Worth the Cost Over 316 & 304?

With hundreds of different types of steel alloys on the market, it can be tough to find the perfect metal for your application. In many buying processes, the first consideration is the cost of the metal rather than the performance of the metal—which can be a serious mistake.

There are some cases where paying extra for a different, higher-performing alloy is necessary.

What Makes Grade 317 SS Different from 304 & 316 SS?

304、316和317级不锈钢均被视为奥氏体不锈钢合金。这些合金都具有一些相似的特性，例如高强度，耐腐蚀性以及高浓度的铬和镍。

What separates 316 and 317 SS from 304 SS is that these higher-numbered alloys have added molybdenum in their formulation—grade 316 has about 2-3% molybdenum, and grade 317 has more than 3% molybdenum.

这增加了钼可以极大地提高钢铁的抵抗力，这就是为什么316级SS经常用于化学加工和海洋工业的原因。

However, this added molybdenum content also influences the cost of these two alloys. Grade 317 SS is generally more expensive than grade 316 SS. 316 SS, in turn, is more expensive than grade 304 SS. The exact extra cost varies based on the market at the time.

When is 317 SS Worth the Extra Cost Over 316 SS?

For most strongly corrosive applications, grade 316 should be more than enough to resist frequent exposure.

但是，317的确比304或316具有更好的特定腐蚀性耐药性。如ATI金属出版物所述，在1％盐酸的沸腾测试溶液中，317 SS的腐蚀速率为542 Mils/年，316 SS以226密耳/年的腐蚀。317 SS在硫酸和氢氧化钠测试中也显着优于316 SS。

因此，如果您的过程涉及使用非常稀释（小于3-4％）的盐酸，轻度浓度（10％）硫酸或氢氧化钠（aka苛性钠苏打钠），那么317级无钢钢可能值得多余费用超过316或304 Ss。

重要的是要注意，以上5％以上的任何浓度中的盐酸都会轻松侵蚀任何奥氏体不锈钢合金。

Also, in the previously-cited chemical corrosion tests, 317 performed worse against some corrosives than 316, such as phosphoric acid (0.72 mils/year vs 0.2 mils/year) and acetic acid (0.48 mils/year vs 0.12 mils/year).

物质不锈钢等级

Also known as "marine grade" stainless steel due to its increased ability to resist saltwater corrosion compared to type 304. SS316 is often used for building nuclear reprocessing plants.