CWI 공부하기2

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미국 용접검사원 CWI 라는 자격증을 소개하고자 한다.
국내 대기업에서도 용접분야의 경력 사원을 뽑는데 이 자격증 소지자를 뽑는 것을 보았다.
국내 용접 자격증의 최상위 등급인 용접기술사와 견줄 수 있는, 국내및 해외에서도 인정을 받은 용접 자격증이라 할 수 있다.
한번 도전해보려고 했지만, 영어로 된 책때문에 도전을 포기해서, 대학원에 진학을 하게 된 계기가 된 자격증이라 할수있다.
용접에 관심 있으신분 들에게 추천 해주고 싶은 자격증 이라고 할 수있다.

*CWI 공부하기2*

 

1. CWI공부해보기2

세계 최고수준의 용접 기술, 우크라이나 `빠튼 전기용접연구소` 한국 온다 - 디지털데일리

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  1. 5.6.4.1 Root and Face-bend test preparation.

The root- xxxxxxxxx xxxxxxx transveres to the weld. 의 내용을 보기에서 주고 맞는 것(틀린 것) 찾는 문제

 

  1. 9.3.1 Inadequate penetration without High-low

Inadequate xxx xxx 내용 후 맞는 것(틀린 것) 찾는 문제

 

 

  1. 6.4 Visual examination

For a qualification test weld to xxxx xxxx xxx testing.

Undercut 에 대한 사항을 보기에 주어놓고 맞는 것(틀린 것) 찾는 문제

 

  1. A.5.1.5 Transverse planar imperfections.

The height of the stacked imperfections from weld starts and stops shall not exceed 50% of the wall thickness.(문제를 응용해서 푸는 문제 기출문제에 있음.)

When using the alternative girth welding what is the max height of stacked imperfection from weld starting ans stop in a weld on pipe 1/2″ thickness

  1. a) 1/16 b)1/8 c) 3/16 d)1/4 5) 5/16

 

  1. 4.2.3.1 Shielding Gases Types 문제

The purity and dryness of these atmospheres have great influence on welding and should be of values suitable for the process and the materials to be welded.

 

  1. 5.6.3.3 Nick break test requirements.

Fisheyes, as defined in AWS A3.0, are not cause for rejection.

 

  1. A.4 Qualification of Welders.

Welders shall be qualified in accordance with Section 6. for mechanized welding, each operator shall be qualified in accordance with 12.6

 

  1. 7.1 General

The surfaces to be welded shall be smooth, uniform, and free from laminations, tears, scale, slag, grease, paint, and other deleterious material that might adversely affect the welding.

 

  1. 7.2 Alignment

For pipe ends of the same nominal thickness, the offset should not exceed 1/8in(3 mm)

2.CWI 공부해보기2

2.1 미국용접검사원에 도전해보세요

  1. 5.3.2 Procedure specification information

Specification에 포함되는 사항들을 열거하고 고르는 문제,

 

  1. B.1 General

For hydrogen cracking to occur, three conditions must be satisfied simultaneously. These conditions are : hydrogen in the weld, the development of a crack-ssusceptible weld microstructure, and tensile stress acting on the weld.

 

  1. 5.6.3.3 Nick-break test requirements(Destructive test 관련 가장 많은 문제가 제출됨)

The exposed….xxxxx…..xxxxx…between adjacent slag inclusions.사항에 대해서 보기를 주고 맞는 것(틀린 것) 찾는 문제

 

  1. 9.3.3 Inadequate cross penetration

Inadequate cross penetration(ICP) is defined as a subsurface imperfection between the first inside pass and the first outside pass that is caused by inadequately penetrating the vertical land faces. 문제에서는 Both of each side(??) 이런식으로 표현하였음. 지문과 보기가 일치하지 않아서 내용을 읽어보아야 답을 구할 수 있음.

 

 

 

  1. 4.2.3.2 Shielding Gases Storage and Handling

Gases of questionable purity and those in containers that show signs of damage shall not be used.

 

  1. 11.1.8

Whenever mor than one image is used to inspect a weld, identification markers shall appear on each image, and adjacent images shall overlap.

 

  1. A.2.2.2 Environmental efffects on fatigue.

The enlargement of weld imperfections 엳 새 fatigue is a function of stress intensity, cycles of loading, imperfection size, and the enviroonment at the crack tip.

 

  1. A.2.4 Dynamic loading

The stress analysis shall include consideration of potential dynamic loading on girth welds, such as loads from closure of check valves.

 

  1. 5.8.1 Fillet welds preparation

At least four specimens shall be taken and prepared as shownn in Figure 11.

 

3.CWI 공부해보기3

3.1 미국용접 검사원 자격증을 따보자

  1. 12.1 Acceptable processes.

SAW, GMAW, GTAW, FCAW with or without Gases, PAW 외 하나 항목을 주고 찾는 문제

 

  1. A.3.2.2.1

For each of these positions, three specimens shall have the V-notch placed in the weld centerline; and the other three shall have the V-notch placed in the HAZ such that the V-notch intersects the fusion boundary.

 

  1. A.2.2.2.Environmental efffects on fatigue

In the absence of contaminating elements, oil and hydrocarbons are considered no worse than air. Water, brine, and aqueous solution that contain CO2 or H2S may, however, increase the growth rate. 내용을 해석해서 이해해야지 보기에서 답을 찾을 수 있게 문제가 나왔음. 주요 키 포인트는 oil and hydrocarbons are considered no worse than air

 

  1. 11.1.2.2 Film radiography
  2. Radiation source.
  3. Intensifying screens.
  4. Film
  5. Exposure geometry
  6. Exposure conditions.
  7. Processing.
  8. Materials.. 등. 항목에 대한 문제

 

  1. A.3.2.2 Charpy impact energy.

시험 방법의 종류를 묻는 문제, Charpy V-notch impact test, CTOD Toughness testing

 

  1. 12.4.2 Specification information.

Specification 항목에 대한 이해문제

 

  1. 10.3.1 Repair acceptance criteria

Repaired areas shall be inspected by the same means previously used.

 

  1. 7.7 Cleaning between beads.

When semiautomatic or mechanized welding is used, surface porosity clusters, bead starts, and high points shall be removed by grinding before weld metal is deposited over them.

차폐 금속 아크 용접 - 위키백과, 우리 모두의 백과사전

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4.CWI공부하기2

4.1 미국용접검사원 열심히 공부하자!!

  1. 9.5.2 Acceptance standards(PT)

결함의 평가에 대한 문제가 나옴. PT는 최초로 나온걸로 알고 있습니다.

문제는 평가에서 a. Linear indications are evaluated as crater cracks or star cracks and exceed 5/32 in.(4mm) in length(Crater Cracks or Star Cracks로 평가된 선형지시가 길이 5/32 inch(4mm) 초과 시). 부분인데 보기에서는 5/32in(4mm)가 불합격이다라는 보기와 6mm가 불합격이다 라는 보기 2개가 나왔습니다. 자세히 읽어보지 않으면 자칫 실수로 4mm가 불합격이다에 답을 하는 실수를 범할 수 있을 것 같습니다.

 

  1. A.5.3 Arc burns.

Arc burns that contain cracks visible to the eye or on conventional radiographs are not covered by this appendix and shall be repaired or removed.

 

  1. B.2.1.1.1 pipe and fitting materials.

The carbon equivalent, 성분 문제

 

  1. B.4.2 Welding sequence

the longitudinal seams should be completed before beginning the circumferential welds.

 

  1. 6.1 Qualification of welders general 부분

A welder shall qualify for welding by performing a test on segments of pipe nipples or on full-size pipe nipples, as specified in 6.2.1. When segments of pipe nipples are used, they shall be supported so that typical flat, vertical, and overhead welds are produced.

 

  1. 5.6.4.3 bend requirements.

The bend test shall xxx xxxx xxxx meet these requirements. 내용 나열 후 맞는 것(틀린 것) 찾는 문제

 

  1. 7.2 Alignment

Larger variations are permissible provided the variation is caused by variations of the pipe end dimensions within the pipe purchase specification tolerances. and such variations have been distributed essentially uniformly around the circumference of the pipe.

 

  1. 7.4.2 Field bevel

Pipe ends should be field beveled by machine tool or machine oxygen cutting. If authorized by the company, manual oxygen cutting may also be used.

 

  1. 7.3 Use of lineup clamp for butt welds.

When it is permissible to remove the lineup clamp before the root bead is completed.

5. 프리랜서로도 활동할수있는 용접검사원(CWI)자격증

5.1 CWI열심히 공부해보기 5

 

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