{"id":4093,"date":"2025-06-11T22:26:16","date_gmt":"2025-06-11T19:26:16","guid":{"rendered":"https:\/\/www.defencemetal.com\/?p=4093"},"modified":"2026-09-17T23:08:02","modified_gmt":"2026-09-17T20:08:02","slug":"17-4-ph-1-4542-aisi-630-ams-5604-ams-5622-ams-5643-stainless-steel","status":"publish","type":"post","link":"https:\/\/www.defencemetal.com\/index.php\/2025\/06\/11\/17-4-ph-1-4542-aisi-630-ams-5604-ams-5622-ams-5643-stainless-steel\/","title":{"rendered":"17-4 PH (1.4542 \/ AISI 630) \u2014 AMS 5604 \/ AMS 5622 \/ AMS 5643 Stainless Steel"},"content":{"rendered":"

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We supply 17-4 PH.<\/strong> For sizes, standard equivalents, stock and quotations, take a look at the 17-4 PH product page<\/strong><\/a>.<\/div>\n

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17-4 PH<\/b><\/h3>\n

<\/b>17-4 PH Stainless Steel: The Optimum Balance of High Mechanical Strength and Corrosion Resistance<\/b><\/b><\/h3>\n

17-4 PH stainless steel is a versatile engineering material in the precipitation hardening<\/a> martensitic stainless steel class, standing out for its high mechanical strength, good toughness and satisfactory corrosion resistance. Regarded as the forerunner of advanced variants such as 15-5 PH and 13-8<\/a> Mo, 17-4 PH has been used for some 70 years across a wide industrial field, from aerospace to petrochemicals. Thanks to the copper and niobium it contains, its mechanical properties can be raised by heat treatment. That property makes it one of the most popular choices among the \u201cage-hardening stainless steels\u201d.<\/p>\n

17-4 PH Chemical Structure and Microstructural Properties<\/b><\/b><\/h3>\n

The name 17-4 PH indicates that the alloy contains roughly 17% chromium and 4% nickel. This basic composition gives the alloy both its stainless character and a structure suitable for precipitation hardening. The alloy typically contains 3\u20135% copper and between 0.15 and 0.45% niobium. Copper causes intermetallic precipitates to form during the ageing heat treatment, and high hardness values are reached in this way. Niobium, in turn, forms carbides with carbon and provides stability at the grain boundaries.<\/p>\n

After solution annealing the alloy has an austenitic structure. Rapid cooling transforms it to a martensitic structure. Ageing treatments are applied at various heat treatment grades such as H900, H1025, H1075, H1100 and H1150. After H900 ageing in particular, a tensile strength of over 1300 MPa and a hardness of roughly 44 HRC can be obtained. This hardening mechanism relies on the spread of copper-rich precipitates in the microstructure.<\/p>\n

Standardisation and Quality Control for 17-4 PH<\/b><\/b><\/h3>\n

17-4 PH is regulated by various internationally recognised standards. The most important standards are:<\/p>\n