30 칠월 2026

단조 합금강 플랜지의 NDT 검사 방법

기술 가이드검토됨: 30 칠월 2026작성자: SASA FLANGE 기술콘텐츠팀

직접적인 답변

Forged alloy steel flange inspection can combine visual testing (VT), magnetic-particle testing (MT), liquid-penetrant testing (PT) and ultrasonic testing (유타). Each method finds different discontinuity types. The correct method, 정도, timing and acceptance criteria must be specified by the governing standard, code and purchase order.

주요 시사점

  • No single NDT method proves total flange integrity.
  • MT suits ferromagnetic alloy steel surfaces; PT is useful for surface-breaking flaws on many nonporous materials.
  • UT technique and calibration must account for flange geometry and the required examination volume.

What each NDT method contributes

방법 Best suited to Key limitation
VT Surface condition, laps, cracks, damage, workmanship and marking Only visible conditions
MT Surface and near-surface discontinuities in ferromagnetic steel Not applicable to austenitic stainless grades
PT Surface-breaking discontinuities on nonporous surfaces Does not find buried flaws
유타 Internal discontinuities within an examinable forging volume 기하학, grain structure and scan access affect coverage

Inspection stage matters

Examination before final machining may provide access to the forging volume, while final-surface examination can detect machining or finishing damage. Heat treatment should occur before the specified final NDT stage when the procedure requires examination of the delivered condition.

Repairs, re-heat treatment or weld build-up can trigger re-examination. The purchase order should state hold and witness points.

Acceptance criteria must be written

A report that says “UT OK” is weak evidence unless it identifies the procedure, 구경 측정, coverage, sensitivity, acceptance standard, operator qualification and item traceability. Different projects can apply different allowable indications.

Define the code paragraph, ASTM practice, owner specification or approved procedure that governs acceptance.

What a useful NDT report includes

  • Flange description, heat number and item identification
  • 방법, written procedure and acceptance criteria
  • 장비, probe or consumable details and calibration
  • Examination surfaces, coverage and stage
  • Indication records and disposition
  • Operator name, certification level, date and authorization

자주 묻는 질문

Is MT better than PT for F22 flanges?

MT is often efficient for ferromagnetic F22 surfaces and can detect near-surface indications, but the project procedure determines the required method and sensitivity.

Does UT replace mechanical testing?

아니요. UT examines internal discontinuities; 인장, impact and hardness tests address material properties.

Should finished sealing faces receive NDT?

Final visual inspection is essential, and surface NDT may be specified. The method must avoid damaging or contaminating the finished face.

관련 합금 플랜지 가이드

플랜지 PMI 테스트 Flange Hardness Testing F11 F22 F91

참조된 기본 표준

항상 구매 주문서에 명시된 버전을 확인하고 설계 및 승인에 대한 완전한 통제 표준을 확보하십시오..

합금강 플랜지 견적 요청

재료 등급 보내기, 기준, NPS, 압력 등급, 플랜지형, 깃 달기, 파이프 일정, 수량 및 검사 요구 사항. SASA FLANGE 견적 전에 기술 설명을 검토합니다..

견적 요청 보내기플랜지 제품 보기

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