{"id":1831,"date":"2026-05-08T00:41:08","date_gmt":"2026-05-08T07:41:08","guid":{"rendered":"https:\/\/www.songhaiflanges.com\/?p=1831"},"modified":"2026-05-12T17:58:49","modified_gmt":"2026-05-13T00:58:49","slug":"cb-3380-1991-macro-etching-test-method-for-marine-steel-weld-joints","status":"publish","type":"post","link":"https:\/\/www.songhaiflanges.com\/ru\/cb-3380-1991-macro-etching-test-method-for-marine-steel-weld-joints\/","title":{"rendered":"CB 3380-1991: Macro Etching Test Method for Marine Steel Weld Joints"},"content":{"rendered":"

Standard Overview<\/h2>\n

Standard Number:<\/strong> CB 3380-1991<\/p>\n

Title:<\/strong> Macro Etching Test Method for Macrostructural Defects in Marine Steel Weld Joints<\/p>\n

Industry:<\/strong> Marine Engineering \/ Shipbuilding<\/p>\n

Status:<\/strong> Chinese Shipbuilding Industry Standard<\/p>\n

Scope<\/h2>\n

This standard specifies the macro etching test method for examining macrostructural defects in welded joints of marine steel structures. The method is used to reveal defects such as:<\/p>\n

    \n
  • Incomplete penetration<\/li>\n
  • Cracks and fissures<\/li>\n
  • Porosity and gas pockets<\/li>\n
  • Slag inclusions<\/li>\n
  • Weld bead profile irregularities<\/li>\n
  • Heat-affected zone characteristics<\/li>\n<\/ul>\n

    Test Principle<\/h2>\n

    The macro etching test involves cutting a cross-section of the weld joint, polishing the surface, and then etching it with an appropriate chemical reagent to reveal the macrostructure. The etched surface is then visually examined or photographed for defect analysis.<\/p>\n

    Key Test Parameters<\/h2>\n\n\n\n\n\n\n\n
    Parameter<\/th>\nSpecification<\/th>\n<\/tr>\n
    Sample Preparation<\/td>\nCross-section perpendicular to weld direction<\/td>\n<\/tr>\n
    Surface Finish<\/td>\nPolished to mirror finish before etching<\/td>\n<\/tr>\n
    Etching Reagent<\/td>\nAcid solution (typically 4% Nital or similar)<\/td>\n<\/tr>\n
    Etching Time<\/td>\nAs specified in standard procedure<\/td>\n<\/tr>\n
    Examination Method<\/td>\nVisual inspection with magnification (5-10x)<\/td>\n<\/tr>\n<\/table>\n

    Applications<\/h2>\n

    This test method is widely used in:<\/p>\n

      \n
    • Ship hull construction quality control<\/li>\n
    • Marine pipeline weld inspection<\/li>\n
    • Offshore structure fabrication<\/li>\n
    • Welding procedure qualification<\/li>\n
    • Failure analysis of welded components<\/li>\n<\/ul>\n

      Download Original Standard<\/h2>\n
      \n

      \ud83d\udcc4 Original PDF Document (Chinese)<\/h3>\n

      Download the complete CB 3380-1991 standard document:<\/p>\n

      \ud83d\udce5 Download CB 3380-1991 PDF<\/a><\/p>\n

      File size: 228.0 KB | Format: PDF<\/p>\n<\/div>\n