17-4PH stainless steel (630 stainless steel)
17-4PH stainless steel is a martensitic precipitation hardening stainless steel, equivalent to the Chinese brand: 0Cr17Ni4Cu4Nb. 17-4PH precipitation hardening steel with copper added. 17-4PH is used to manufacture shafts and steam turbine parts.
Chinese name 17-4PH stainless steel standard AISI, ASTM type number 17-4PH (SUS630) UNS number S17400
●17-4PH characteristics and applications:
●17-4PH chemical composition①:
| C |
Mn |
Si |
Cr |
Ni② |
P |
S |
Cu |
Niobium+tantalum Nb+Ta |
| ≤0.07 |
≤1.00 |
≤1.00 |
15.5~17.5 |
3.0~5.0 |
≤0.04 |
≤0.03 |
3.0~5.0 |
0.15~0.45 |
●17-4PH mechanical properties:
Tensile strength σb (MPa): aging at 480°C, ≥1310; aging at 550°C, ≥1060; aging at 580°C, ≥1000; aging at 620°C, ≥930
Conditional yield strength σ0.2 (MPa): aging at 480°C, ≥1180; aging at 550°C, ≥1000; aging at 580°C, ≥865; aging at 620°C, ≥725
Elongation δ5 (%): aging at 480°C, ≥10; aging at 550°C, ≥12; aging at 580°C, ≥13; aging at 620°C, ≥16
Reduction of area ψ (%): aging at 480℃, ≥40; aging at 550℃, ≥45; aging at 580℃, ≥45; aging at 620℃, ≥50
Hardness: solid solution, ≤363HB and ≤38HRC; aging at 480℃, ≥375HB and ≥40HRC; aging at 550℃, ≥331HB and ≥35HRC; aging at 580℃, ≥302HB and ≥31HRC; aging at 620℃, ≥277HB and ≥28HRC
●17-4PH heat treatment specification and metallographic structure:
Heat treatment specifications: 1) rapid cooling at 1020～1060℃; 2) aging at 480℃, after solution treatment, air cooling at 470～490℃; 3) aging at 550℃, after solution treatment, air cooling at 540～560℃; 4) Aging at 580℃, after solution treatment, air cooling at 570～590℃; 5) Aging at 620℃, after solution treatment, air cooling at 610～630℃.
Metallographic structure: The structure is characterized by precipitation hardening.
●17-4PH delivery status: generally delivered in the heat treatment state, the type of heat treatment is indicated in the contract; if it is not specified, it will be delivered in the non-heat treatment state.
Note: ①A single value is the highest value unless otherwise specified; ②When used in certain pipe making processes, the nickel content of some types of austenitic stainless steel must be slightly higher than the value shown in the table; ③ Random; ④The highest TA content is 0.10%; ⑤The highest content is 0.75%; ⑥The highest content is 0.70%
17-4PH alloy is precipitation, hardening, martensitic stainless steel.
17-4PH alloy is a precipitation, hardening, martensitic stainless steel composed of copper and niobium/columb.
This grade has high strength, hardness (up to 300°C/572°F) and corrosion resistance.
After heat treatment, the mechanical properties of the product are more perfect, and can reach a compressive strength of up to 1100-1300 mpa (160-190 ksi).
This grade cannot be used at temperatures higher than 300°C (572°F) or very low temperatures. It has good corrosion resistance to the atmosphere and diluted acids or salts. Its corrosion resistance is the same as 304 and 430.
17-4PH application field:
· Offshore platforms, helicopter decks, other platforms
· food industry
· Pulp and Paper Industry
· Aerospace (turbine blades)
· machinery parts
· Nuclear Waste Barrel
