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

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!

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

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?

Stainless Steel Material: How is stainless steel made?

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?

Stainless Steel Material: what is stainless steel?

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?

Stainless Steel Pipe Inspection Notes!- Part 2

Continue:        7. Non Destructive Test: base on rule, % welding joint need to do NDT will be choosen. For ex: (1)  Apply at least 10% of random RT to butt joint based on the class rule. (Choose RT point upon the decision of QM) (2)  Apply 100% of random RT to stern cargo line 8. Pipe Covering / Protection (1)  After the inspection of pipe at shop and before the coating process, do the covering to the tip of the pipe based on sealing rule. This can protect the pipe from foreign substance influx. (2)  After the coating … Continue reading Stainless Steel Pipe Inspection Notes!- Part 2

Stainless Steel Pipe Inspection Notes!- Part 1

Range of Application This guideline applies to stainless steel piping work during the fabricate & installation on board. Purpose Stainless steel pipe is widely used for its strength against low temperature and corrosion, and it is mainly used for low-temperature and chemical products. To maintain these characteristics, special management is required in the process of storage, assembly, welding, and post-processing. The purpose of this guideline is to offer standardized working methods to maintain the proper quality of piping system. Definition Sus pipe is composed of austenite and it is extremely durable against low / cryogenic temperature. Cr₂O₃ is formed on … Continue reading Stainless Steel Pipe Inspection Notes!- Part 1

How to view the material certificate? – Part 3 ( Final part )

Continue:  PART 3  – Fake certificate: Why have the FAKE CERT? The Certified Mill Test Report is a tool used to ensure that received raw material matches the engineering and purchase order requirements. There are clear requirements for what should go on the certificate but every so often someone tries to produce a fake mill certificate to sell steel plates fraudulently. 2. How to identify a FAKE STEEL MTCS? A fake mill certificate is normally fairly easy to spot if you know what you are looking for. You can sent them an email asking to vendor to clarify this certificate. … Continue reading How to view the material certificate? – Part 3 ( Final part )

How to view the material certificate? – Part 2

Continue:  PART 2 – How to view the certificate??? We will take example for Mill cert’, other cert’ is same procedure. Mill cert:  A Certified Mill Test Report (CMTR) is a quality assurance document generated by the raw material manufacturer and provided with the material to intermediate suppliers and ultimately to a finished goods manufacturer. Whether it’s called a CMTR, Mill Test Report (MTR), Mill Certification, Metallurgical Test Report, or similar name, this document provides the end user of the raw material verification that the material received matches the requirements of their order. CMTRs are also used to maintain traceability … Continue reading How to view the material certificate? – Part 2

TACK WELDER

Tack welding is a major part of welding which are used as a temporary means to hold the components in the proper location, alignment, and distance apart, while welding. The engineers use high heat input process for the welding and the tack is applied by the shielded metal arc welding process. The tack is a very rapid quench application and a brittle, crack sensitive micro structure results usually at the root of the weld. There’re two type of tack-welds as defined in below attached file ( Temporary & Incorporated ) TACK WELDS For saving the qualification cost, some yard make … Continue reading TACK WELDER