{"id":3567,"date":"2026-05-22T06:33:39","date_gmt":"2026-05-22T06:33:39","guid":{"rendered":"https:\/\/asiabolt.om\/?post_type=product&#038;p=3567"},"modified":"2026-06-27T10:34:31","modified_gmt":"2026-06-27T10:34:31","slug":"passivation-stainless-steel","status":"publish","type":"product","link":"https:\/\/asiabolt.om\/ar\/product\/passivation-stainless-steel\/","title":{"rendered":"Passivation (Stainless Steel)"},"content":{"rendered":"<p>Passivation is a post-machining or post-fabrication chemical treatment applied to stainless steel fasteners to maximise their natural corrosion resistance. Stainless steel derives its corrosion resistance from a thin, self-regenerating chromium oxide (Cr\u2082O\u2083) passive layer on its surface. However, machining, forming, and handling operations can introduce free iron contamination that compromises this layer \u2014 making passivation a critical quality step.<\/p>\n<p>Asia Bolts Industries performs passivation on all stainless steel fasteners (304, 316, 316L, 316Ti, 317L, 904L, Duplex 2205, Super Duplex 2507) per ASTM A967 and AMS 2700.<\/p>\n<p>Passivation Process: 1. Pre-clean: Alkaline cleaning to remove oils, cutting fluids, and organic contamination 2. Acid Treatment: Immersion in nitric acid (HNO\u2083) or citric acid solution to dissolve free iron\u00a0\u00a0\u00a0 \u2022 Method 1: Nitric acid (20\u201345% concentration, 20\u201360 min at 21\u201349\u00b0C)\u00a0\u00a0\u00a0 \u2022 Method 2: Citric acid (4\u201310% concentration) \u2014 preferred eco-friendly alternative 3. Water rinse and dry 4. Verification: ASTM A967 copper sulphate test or high humidity test to confirm passive layer integrity<\/p>\n<p>ASTM A967 Practice Classifications: \u2022 Nitric 1: 20\u201325% HNO\u2083 at 21\u201332\u00b0C \u2022 Nitric 2: 20\u201345% HNO\u2083 at 49\u201360\u00b0C \u2022 Citric 1\u20134: Varying citric acid concentrations and temperatures<\/p>\n<p>Key Outcomes: \u2022 Removal of all free iron from surface \u2022 Restoration of chromium oxide passive layer \u2022 Significantly improved resistance to pitting corrosion in chloride environments \u2022 Compliance documentation for critical oil &amp; gas, food, pharma applications<\/p>\n<p>All passivated stainless fasteners from Asia Bolts are supplied with passivation practice designation, test method used, and material certification per heat\/lot.<\/p>","protected":false},"excerpt":{"rendered":"<p>Passivation is a chemical treatment applied to stainless steel fasteners to remove free iron contamination and restore the natural chromium oxide passive layer. Applied per ASTM A967 and AMS 2700. Essential for stainless steel fasteners used in food, pharmaceutical, offshore, and chemical process environments where maximum corrosion resistance is required.<\/p>\n<table width=\"624\">\n<tbody>\n<tr>\n<td width=\"120\"><strong>Standard<\/strong><\/td>\n<td width=\"504\">ASTM A967 \/ AMS 2700 (referenced)<\/td>\n<\/tr>\n<tr>\n<td width=\"120\"><strong>Base Material<\/strong><\/td>\n<td width=\"504\">Stainless Steel (304, 316, 316L, Duplex 2205, Super Duplex 2507)<\/td>\n<\/tr>\n<tr>\n<td width=\"120\"><strong>Salt Spray<\/strong><\/td>\n<td width=\"504\">1,000+ hours (316L after passivation)<\/td>\n<\/tr>\n<tr>\n<td width=\"120\"><strong>Thickness<\/strong><\/td>\n<td width=\"504\">2\u20135 nm (molecular passive layer \u2014 not measurable conventionally)<\/td>\n<\/tr>\n<tr>\n<td width=\"120\"><strong>Applications<\/strong><\/td>\n<td width=\"504\">Food grade, pharmaceutical, offshore marine, chemical process, desalination<\/td>\n<\/tr>\n<\/tbody>\n<\/table>","protected":false},"featured_media":3571,"template":"","meta":{"_kadence_starter_templates_imported_post":false},"product_brand":[],"product_cat":[212],"product_tag":[],"class_list":["post-3567","product","type-product","status-publish","has-post-thumbnail","product_cat-fastener-coatings-surface-treatments","first","instock","shipping-taxable","product-type-simple"],"_links":{"self":[{"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product\/3567","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/media\/3571"}],"wp:attachment":[{"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/media?parent=3567"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product_brand?post=3567"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product_cat?post=3567"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/asiabolt.om\/ar\/wp-json\/wp\/v2\/product_tag?post=3567"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}