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What’s the difference between high strength bolt and common bolt?

High strength bolt is the most common construction content in steel structure construction. All steel structure engineers will feel that they are too familiar with it. However, this may not be the case. Today, we start with the most basic concepts and take you to re understand the high-strength bolt, which may overturn your most basic understanding. Contents: What is high strength bolt Specification of high strength bolt Bolt axis tension axial deformation curve Comparison between high strength bolt and common bolt Bolt tightening method Conclusion 01. What is high strength bolt High strength friction grip bolt (HSFG for short). […]

2019-10-27

Development of duplex stainless steel in China

Based on the development history of duplex stainless steel in the world, the development of duplex stainless steel in research, production, application and standards in China in recent years is described. The investigation shows that in recent years, the output of duplex stainless steel in China has increased considerably, and its steel composition has gradually evolved into a structure with 2205 (SAF 2205, also known as Sandvik SAF 2205, is a Sandvik-owned trademark for a 22Cr duplex (ferritic-austenitic) stainless steel.) as the main component and multi-steel series as the cooperative development. Especially after 2019, the economical duplex stainless steel and […]

2019-10-12

Failure Analysis of Surface Stellite Alloy Overlayer on Disc of Wedge Gate Val……

Stellite alloy, commonly known as cobalt-based alloy, is a kind of cemented carbide with Co, Cr and W as the main elements. It can be sprayed on the surface of vulnerable parts by various welding processes, and can also be made into castings [1_4]. Due to its characteristics of wear resistance, corrosion resistance, oxidation resistance and high temperature resistance, it is widely used in various hard coatings or contact sealing surfaces [5 7]. Visual inspection in a nuclear power plant found that the surfacing layer of Stellite alloy on the sealing surface of both sides of a wedge gate valve […]

2019-09-30

Research Progress of Nickel-based Corrosion Resistant Alloys

Nickel-based alloys not only have unique corrosion resistance and even high temperature corrosion resistance in many industrial corrosive environments, but also have high strength, good plasticity and toughness. They can be smelted, cast, cold and hot deformation, processing and welding, and are widely used in petrochemical, energy, marine, aerospace and other fields. 1. Composition and Classification Nickel is completely stable in alkali solution and has excellent corrosion resistance to active gases (such as fluorine, chlorine, bromine and their hydrides), hydroxides (such as NaOH, KOH) and some organic compounds. The main role of alloying elements in resisting corrosion in aqueous solution […]

2019-08-12

Corrosion Behavior of 316LN Welded Joints in High Temperature and High Pressur……

The primary circuit main pipeline, known as the “aorta” of nuclear power plants, is one of the seven key equipment in the nuclear island. It connects the reactor pressure vessel, steam generator and reactor coolant pump to form a closed loop. The main pipe consists of two loops, and there are 12 welded joints [1,2]. In the operation environment of nuclear power plant, these stainless steel welded joints will inevitably be corroded by high temperature and high pressure boron water in the primary circuit of nuclear power plant. The stability of the welded joints is related to the safety of […]

2019-07-27

Identification Method of Seamless Steel Pipe and Welded Steel Pipe

Today, a client sent me some pictures to help him see if the carbon steel pipe is seamless or welded. The size of the steel pipe is 133 *4.5mm, and the outside diameter of the pipe is 133mm and the thickness is 4.5mm. The contract he signed with the supplier is 133 *4.5mm seamless steel pipe, but he suspected that he met a traitor and gave him welded steel pipe (possibly seamless steel pipe, that is, seamless treatment of welded pipe in the relevant treatment industry, used to impersonate seamless steel pipe, called seamless steel pipe, in fact, it is […]

2019-07-16

What is a SSAW pipe?

What is a SSAW pipe? Spiral submerged arc welded steel pipe is a kind of metal pipe with spiral seam welded by submerged arc welding technology. SSAW pipe is made of hot rolled coiled steel by automatic submerged arc weld under normal atmospheric temperature. All the pipes are produced according to API Spec 5L, GB/T9711.1, GB/T9711.2, ASTM A252-89 standard. These pipes mainly used in petroleum and natural gas industry to transport flammable and non-flammable liquid and steel construction. Classfication of SSAW Steel Pipe Chemical Analysis and Mechanical Properties of SSAW pipe Tolerance of OD and WT of SSAW Steel Pipe […]

2019-04-14

Difference between 304, 304L, 316 and 316L in the valves field

What is Stainless Steel? Stainless steel is a type of steel. Steel refers to steel containing less than 2% carbon (C) and iron is more than 2%. The addition of chromium (Cr), nickel (Ni), manganese (Mn), silicon (Si), titanium (Ti), molybdenum (Mo) and other alloying elements in the smelting process improves the properties of the steel and makes the steel resistant to corrosion. (that is, not rust) is the stainless steel we often say. What is the meaning of “steel” and “iron”, what are the characteristics, and what is the relationship between us, 304, 304L, 316, 316L, which we usually […]

2019-03-09

Forged valve installation and maintenance methods

The quality of the forged valve installation directly affects its use, so the forged valve installation must be treated carefully. 1. The direction and position Many forged valves should be installed in a specific direction. If they are installed in a reversed direction, the operation effect and service life will be affected, or the forged valves will not work at all, and even cause danger. Generally, the forged valve has a direction mark on the forged valve body; if not, it should be correctly identified according to the working principle of the forged valve. The valve chamber of the globe […]

2019-02-14

Valve sealing

1, the principle of valve sealing Sealing is to prevent leakage, so the principle of valve sealing is also studied from leak prevention. There are two main factors that cause leakage. One is the most important factor affecting the sealing performance, that is, there is a gap between the sealing pairs, and the other is the pressure difference between the two sides of the sealing pair. The principle of valve sealing is also analyzed from four aspects: liquid sealing, gas sealing, leakage channel sealing principle and valve sealing pair. [1] Liquid tightness The tightness of the liquid is carried out by the […]

2019-01-20

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What’s the difference between high strength bolt and common bolt?

Development of duplex stainless steel in China

Failure Analysis of Surface Stellite Alloy Overlayer on Disc of Wedge Gate Val……

Research Progress of Nickel-based Corrosion Resistant Alloys

Corrosion Behavior of 316LN Welded Joints in High Temperature and High Pressur……

Identification Method of Seamless Steel Pipe and Welded Steel Pipe

What is a SSAW pipe?

Difference between 304, 304L, 316 and 316L in the valves field

Forged valve installation and maintenance methods

Valve sealing