Author: Thanh ( QC ) Nguyen Le

-M&P QC ( Quality control ) -Worked at Hyundai Vinashin -Working at Triyards
CSWIP 3.0/3.1/3.2, WELDING2 Comments

CSWIP 3.1: Part 2 – Typical Duties Of Welding Inspectors

Thanh ( QC ) Nguyen Le

Duties and Responsibilities: 1) Give the three main responsibilities of a Welding Inspector: Code compliance Workmanship control Documentation control 2) Give the main attributes, which all Welding Inspectors must possess: Honesty Integrity Knowledge Good communicator Physical fitness 3) A Welding Inspector should refer to What documents and records: Welding Inspection Personnel should: be familiar with relevant standards, rules and specifications applicable to the fabrication work to be undertaken. For ex: BS EN 970 – Non-destructive examination of fusion welds – Visual examination be informed about the welding procedures to be used have good vision (which should be checked every 12 months) 4) Give main … Continue reading CSWIP 3.1: Part 2 – Typical Duties Of Welding Inspectors

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Stainless Steel Material: what is pickling / passivation?

Thanh ( QC ) Nguyen Le

Stainless Steel material: ( refer to other topic: what is stainless steel? ) A metallic alloy (i.e., metal made of multiple elements such as chromium, nickel, and molybdenum) is generally considered to be “stainless” when its chromium content is greater than about 12 percent by weight ( some document mention it is about 10.5% chromium ), with the balance being iron, higher alloyed stainless steels have higher levels of chromium. Chromium provides corrosion resistance to these alloys by forming a thin, adherent, corrosion-resistant oxide film on a clean (e.g., pickled, wire/rotary brushed, or ground) surface (of the alloy). The main … Continue reading Stainless Steel Material: what is pickling / passivation?

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CSWIP 3.1 ( Welding Inspection ): Part 1 – What is it?

Thanh ( QC ) Nguyen Le

Dear all, With this topic, we will talk about CSWIP with a series as much as possible. Part 1: CSWIP – What is it? CSWIP is Certification Scheme for Welding & Inspection Personnel. The CSWIP 3.1 Welding Inspector course provides an introduction to a wide range of topics related to Welding Inspection and Quality. Course Contents: Roles and duties of a Welding Inspector Welding Defects Mechanical Testing Main Welding Processes Welding Symbols Non-Destructive Testing Inspection Reporting Welding Terminology Welding Safety Heat Treatments Weldability of Steels Joint Design Welding Procedures Welder Qualification Stress and Distortion Macro Examination Codes and Standards Welding Consumables … Continue reading CSWIP 3.1 ( Welding Inspection ): Part 1 – What is it?

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Why Stainless steel rust / corrosion? – Part 2 – Other corrosion.

Thanh ( QC ) Nguyen Le

In Part 1, we know about Pitting corrosion. We will continue with remain one: 2) Crevice ( gap ) corrosion– Stainless steel requires a supply of oxygen to make sure that the passive layer can form on the surface. In very tight crevices, it is not always possible for the oxygen to gain access to the stainless steel surface thereby causing it to be vulnerable to attack. Crevice Corrosion refers to the localized attack on a metal surface at, or immediately adjacent to, the gap or crevice between two joining surfaces. The gap or crevice can be formed between two metals or a … Continue reading Why Stainless steel rust / corrosion? – Part 2 – Other corrosion.

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Why Stainless Steel Rust / Corrosion? – Part 1 – Pitting Corrosion!

Thanh ( QC ) Nguyen Le

Although stainless steel is much more resistant to corrosion than ordinary carbon or alloy steels, sometime we see rust on Stainless steel. It is ‘stain-less’ not ‘stain impossible’. Sometime we see rust on Stainless steel.  It means it can corrode. Why??? It has some common forms of corrosion in Stainless steel: Pitting corrosion: (pitting corrosion of stainless steel in a chloride-containing environment) Pitting corrosion is an electrochemical oxidation-reduction (redox) process, which occurs within localized holes (cells) on the surface of metals coated with a passive film. The passive layer on stainless steel can be attacked by certain chemical species. The chloride ion Cl- is the most … Continue reading Why Stainless Steel Rust / Corrosion? – Part 1 – Pitting Corrosion!

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Stainless steel material: what difference between stainless steel and carbon steel?

Thanh ( QC ) Nguyen Le

Selecting an appropriate type of steel for a project is one of the most important decisions to make. However, before deciding between individual grades, you first have to decide what type of steel to use, such as carbon steel or stainless steel. In general, steel is an alloy with Iron being the main element. An alloy is a material made of a mixture of metals or a metal with other elements. These types of alloys are often cheaper and have improved properties. In the case of steel, iron is primarily mixed with carbon and few other elements. Mixing with carbon makes steel stronger, … Continue reading Stainless steel material: what difference between stainless steel and carbon steel?

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Stainless Steel Material: How is stainless steel made?

Thanh ( QC ) Nguyen Le

Stainless steel is known for excellent corrosion resistance. It is an integral part of modern life and is used in a range of applications, including heavy industry, architecture, automotive manufacture, surgery and dentistry. Stainless steel is an iron alloy with added elements such as chromium, nickel, silicon, manganese, nitrogen and carbon. The properties of the final alloy can be fine-tuned by altering the amounts of the various elements. Now we will know How Stainless steel is made? Raw materials:  Stainless steel is the most recycled material in the world and it is estimated that 82% of the stainless steel in use today will be recycled … Continue reading Stainless Steel Material: How is stainless steel made?

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Propeller System: Bolt Tightening for Propeller Blade!

Thanh ( QC ) Nguyen Le

We will talk about How to tight for bolts of blades after assembly! Have some method to do it. But in this topic we will say a simple way to do it & not need modern equipment or tools to do. We will use chain locker! We will take an example for easy understand! 1.Mounting propeller blades: Blades marked according to above figure , Aft view. Mounting sequence: 1-3-2-4. 2. Bolt tightening for blade: – Both pre-tighten and final tighten of the blade bolts with can be done by using socket adapter and ring spanner (a chain block suspended wrench) … Continue reading Propeller System: Bolt Tightening for Propeller Blade!

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Stainless Steel Material: what is stainless steel?

Thanh ( QC ) Nguyen Le

For this topic, we will have a seri about this material type: Stainless steel material. 1.  What is Stainless Steel? 2.  Corrosion Mechanisms 3.  Environmental Factors That Influence Corrosion in Water 4.  Construction and Fabrication Influences on Stainless Steel Corrosion 5.  Material Handling After Fabrication and During Installation /  Stock Materials and Fabrication of Stainless Steel Parts 6. CORROSION RESISTANCE TESTING METHODS 7.  UTILITY AND FABRICATOR EXPERIENCES WITH STAINLESS STEEL CORROSION 8.  GUIDELINES FOR STAINLESS STEEL USE 9. Other… Okay! Now we start. Are you ready? I. What is Stainless Steel? A metallic alloy (i.e., metal made of multiple elements such as chromium, … Continue reading Stainless Steel Material: what is stainless steel?