Order---ERW Steel Pipe shipped to Vietnam

Product: ERW Steel Pipe, Electric Resistance Welded, Carbon Steel
Standard: ASTM A53 GR.B/API 5L GR.B/ASTM A106 GR.B
Specification: 609.6mm*9.53mm*5800mm
Surface: Black Painted
Ends: Bevelled
Quantity: 264 Tons
Production Time: 30 days info@primesteeltube.com

 

Order---Rectangular Pipe shipped to Kuwait

Product: Rectangular Pipe, Electric Resistance Welded, Carbon Steel
Standard: ASTM A500 GR.B
Specification: 500mm*300mm*20mm
Surface: Bared
Ends: Plain End
Quantity: 119 Tons
Production Time: 25 days
Destination: Kuwait info@primesteeltube.com 

Order---SSAW Steel Pipe shipped to Nigeria

Product: SSAW steel pipe, Spiral Submerged Arc Welded, Carbon Steel
Standard: API 5L PSL1 GR.B
Specification: 1000mm*20mm*29.2meters
Surface: 3PE anti-corrosion coated
Ends: Plain End
Quantity: 896 Tons
Production Time: 35 days
Destination: Nigeria info@primesteeltube.com

 

Order---Hot Dipped Glavanized Steel Pipe Shipped to Oman

Product: Hot Dipped Galvanized Steel Pipe
Standard: BS 1387
Specification:
88.9mm*3mm*6.1meters
88.9mm*3.2mm*6.1meters
Surface: zinc coating 210g
Ends: Plain End
Quantity: 66 Tons
Production Time: 25 days
Destination: Oman info@primesteeltube.com

​

Order---SSAW Steel Pipe with 3PE coating shipped to Saudi Arabia

Product: SSAW Steel Pipe, Submerged Arc Welded, Carbon Steel Pipe
Standard: API 5L X52
Specification:
508mm*7.92mm*1200mm
610mm*6.4mm*1200mm
1067mm*9.35mm*1200mm
1219mm*7.92mm*1200mm
Surface: 3PE anti-corrosive Coating (2mm coating thicnkness)
Ends: Bevelled Ends
Quantity: 1228 Tons
Destination: Saudi Arabia

For more finished SSAW Steel Pipe order, please read Order---SSAW Steel Pipe shipped to Nigeria

  

  

Developing Steel Construction can Resolve the Overcapacity

On Januaray 8th and 9th, The Committee of Steel Structure Experts in China has hold the annual meeting in Wuhan, Hubei Province. More than 200 steel structure experts get together and discussion the current steel industry in China. They proposed to develop steel construction so as to defuse the current serious excess steel production capacity. The characteristic ofsteel construction is light, fast ,better and cheaper to use, the experts believes that structural steel is the most suitable for building industrial steel building construction.

During the meeting, the multi-site large-span grid structure is strongely suggested. Also, in order to facilitate the production of prefabrication, a six tetrahedral units of reticulated spherical shell is brough up. According to the latest reportes, eighty percent of steel building components can be processed in the factory, at the same time it is easy to dismantled. Moreover, some products and materials can be reused and recycled. Compared to the traditional concrete construction, steel construction can reduce 40% of weight, increase four times of construction efficiency, shortened 1/3 construction period, reduce 35% of carbon emissions, and also increase 5% of room rate. Therefore, steel structure is more popular in the developed countries.
​
Statistics showed that in the last five years, the amount of steel construction in China is 30 to 50 million tons which is accounting for 5% of steel production totally in Chinese Steel Industry. However, compared with other developed countries, it is very obvious that in China the steel construction application is still in a very low level. The steel construction proportion is over 45% in United State, 28% in Japan, 22% in Germany. Academicians in this meeting believe that developing steel construction can resolve the overcapacity in the Chinese Steel Industry, also it cvan promote the construction of industrialization, to achieve the transformation and upgrading of traditional industries.

Using the Market to Solve the Overcapacity in the Steel Industry

In Januaray, the senior leaders, Li Keqiang has stressed that, under the current overcapacity prescriptions in China, the government will forced to give full play role to the market mechanism. The government will takeing advantage of the market oriented approach to resolve the overcapacity in the Chinese Steel Industry. Specifically, Li Keqiang clearly summarized into three tasks. Including strict control of incremental, proactive reduction, inventory optimization. Besides, Li Keqiang also proposed to highlight production process to solve the "money", "debt", "people" these three key issues. The news reporters has learned that the National Development and Reform Commission, the Ministry and other major ministries have excess capacity on a number of issues to resolve research and deployment policies are expected to be introduced soon.

Li pointed out that the current overcapacity in the two most prominent industry, one steel, one coal. Surplus in these industries has not the industry cycle issues. In the new situation, the government should take " hard measures" to resove the overcapacity. In order to strictly control the incremental, Li Keqiang has stressed that first of all new production has to stopped. Especially, it will not be acceptable to exapnd production capacity under the name of technological innovation.

Finally, Li Keqiang also stressed the need to optimize inventory production capacity, companies want to resolve the overcapacity in the process of the "quantity" cut down, the "quality" to go up, and promote product upgrading, speed up to high-end, smart, green aspects of the transition converting.info@primesteeltube.com

Order---LSAW Steel Pipe shipped to Nigeria

Product: LSAW Steel Pipe, Submerged Aar Welded, Carbon Steel
Standard: API 5L GR.B/ASTM A53 GR.B
Specification:
1928mm*11.5mm*12.01mm
Surface: Balck Painted before shipping
Ends: Bevelled Ends
Quantity: 395 Tons
Destination Port: Nigeria Lagos
​
For more finished LSAW Steel Pipe order, Please read Order---LSAW Steel Pipe shipped to Mexico

Order---Seamless Steel Pipe shipped to UAE

Product: Cold Drawn Seamless Steel Pipe
Standard: API 5L GR.B/ASTM A106 GR.B
Specification:
3'' SCH40 6000mm
4''SCH 40 6000mm
Surface: Balck Painted
Ends: Bevelled Ends
Quantity: 128 Tons
Production Time: 25 days
Destination: UAE

For more Seamless Steel Pipe Order, Please Read Order---Seamless Steel Pipe shipped to Brazil

API Line Pipe Standard Introduction

LINE PIPE:

Line Pipe is one of the transportation method used for transporting oil, natural gas and water through pipeline to the oil and gas industry. 

Line Pipe Type: Seamless Steel Pipe, Welded Steel PipesLine Pipe Ends Type: Plain Ends, Threaded Ends, Socket EndsLine Pipe Connection Type: Welding Connection, Coupling Connection, Socket ConnectionAPI 5L Line Pipe Steel Grade: GR.B, X42, X52, X60, X65, X70, L245, L290, L320, L360, L450, L485
API 5L Line Pipe Specification: 

               -Seamless Steel Pipe Specification: Outside Diameter: 10.3mm ~ 1016mm, Wall Thickness: 1.7mm ~ 52mm;
              - ERW Steel Pipe Specification:  Outside Diameter: 21.3mm ~ 660mm, Wall Thickness: 1mm ~ 20mm;
              - LSAW Steel Pipe Specification: Outside Diameter: 406mm ~ 1626mm, Wall Thickness: 6.0mm ~ 75mm;
              - SSAW Steel Pipe Specification: Outside Diameter: 219mm ~ 4060mm, Wall Thickness: 3.2mm ~ 40mm;

   

API 5L LINE PIPE STANDARD:

ISO 3183 / API 5L Line Pipe Standard is one of the most significant international standards in the oil and gas pipeline industry. Nowadays, API 5L Line Pipe Standard is widely applied all over
the world. Jointly completed by ISO and American Petroleum Institution, the 44th Edition ISO 3187:2007 / API Spec 5L Line Pipe Standard has caused widespread impact internationally. The revision was launched in April 2010, collected and processed more than 400 comments all over the world. At the end of 2012, the edition API 5L Line Pipe Standard was formally approved,
and it was formally released on February 18, 2013. Compared with the previous edition, ISO 3183:2012 / API Spec 5L Line Pipe (45 edition) has added two technical appendices which are
Appendix M: European Onshore Natural Gas Pipeline PSL2 Steel Pipe Order and Appendix P: Threaded and Coupled Calculation Formula, Guide Bending and Charpy Impact Calculation
Background. Besides, in the new edition of API 5L Line Pipe Standard, there are few technological changes such as manufacturing processes, performance indicators, test methods.
The new API 5L Line Pipe Standard is more perfect and science after a lot of editorial changes and textual representation of adjustment. 

API 5L LINE PIPE PSL1 & PSL2:

API 5L Line Pipe Standard has put forward specific requirements on the manufacturing of seamless and welded steel pipe including two steel pipe specification level (PSL1 and PSL2). API 5L
Line Pipe is widely used for petroleum and natural gas industry pipeline transportation systems, but this API 5L Line Pipe criterion is not suitable for the cast iron pipe. PSL is the abbreviation
of Product Specification Level which is the quality level of API 5L Line Pipe. API 5L Line Pipe has two standards which are PSL1 and PSL2. Although these two standard only have one word
difference, the content is very different. PSL2 is a higher quality level than PSL1. Both standard level have different levels of inspection requirements, chemical composition requirements,
mechanical properties requirements, mechanical properties requirements. When making order follow the API 5L Line Pipe Standard, the purchaser need to indicate the level of standard
(PSL1 or PSL2) regard of the basic contract terms such as product specification, steel grades, order quantity etc. In general condition, if the contracts do not mention the standard level,
the manufacturer will produce in accordance with the standard of PSL1. To be more specify, the differences are including:

        1. Pipeline Hydro-static Test should be done piece by piece, and the API 5L Line Pipe Standard does not specify to allow non-destructive alternative hydro-static testing.
        2. Impact performance test is necessary for PSL2 standard, while PSL1 is not necessary for this type of test.         3. Non-destructive Test should be applied for PSL 2 standard pipe piece by piece, while for PSL1 standard is not required. 

API 5L Line Pipe Standard is similar to the Chinese Standard GB/T9711. API 5L Line Pipe PSL1 is equivalent to the GB/T9711.1. Compared with API 5L Line Pipe PLS1, API 5L Line Pipe
PSL2 standard level requires more impact energy experiments, so the production time and production cost for the manufacturers will increase. Besides, API 5L Line Pipe PSL2 standard
requires a higher quality level of raw materials for producing steel pipes, the raw materials ordering time will be longer than the PSL1 standard steel pipe raw materials. Moreover, in order
the reach the quality standard of PSL2 and also control the production cost of the factory, the manufacturer will set up a higher level of minimum order quantity for the purchasers. For
API 5L Line Pipe PSL2, some time purchasers will request for following NACE standard which means during the production the manufacturers have to add hardness and acid resistance test
for the pipes to reach a even higher quality level of steel pipes. 

Tolerance of Outside Diameter

Standard	Out Diameter	Tolerance of Pipe End	Tolerance of Pipe Body
API 5L	219.1～273.1	+1.6mm, -0.4mm	±0.75%
	274.0～320	+2.4mm, -0.8mm	±0.75%
	323.9～457	+2.4mm, -0.8mm	±0.75%
	508	+2.4mm, -0.8mm	±0.75%
	559～610	+2.4mm, -0.8mm	±0.75%

Tolerance of Wall Thickness

Standard	Grade	Out Diameter	Wall Thickness
API 5L	A	219.1～457	+15%, -12.5%
	B	508～610	+17.5%, -12.5%
	X42-X80	508～610	+19.5%, -8%

 Chemical Analysis & Mechanical Properties

Standard	Class	Grade	Chemical Analysis(%)				Mechanical Properties(min)(Mpa)
			C	Mn	P	S	Tensile Strength	Yield Strength
API 5L	PSL1	B	0.26	1.20	0.030	0.030	414	241
		X42	0.26	1.30	0.030	0.030	414	290
		X46	0.26	1.40	0.030	0.030	434	317
		X52	0.26	1.40	0.030	0.030	455	359
		X56	0.26	1.40	0.030	0.030	490	386
		X60	0.26	1.40	0.030	0.030	517	414
		X65	0.26	1.45	0.030	0.030	531	448
		X70	0.26	1.65	0.030	0.030	565	483
	PSL2	B	0.22	1.20	0.025	0.015	414	241
		X42	0.22	1.30	0.025	0.015	414	290
		X46	0.22	1.40	0.025	0.015	434	317
		X52	0.22	1.40	0.025	0.015	455	359
		X56	0.22	1.40	0.025	0.015	490	386
		X60	0.22	1.40	0.025	0.015	517	414
		X65	0.22	1.45	0.025	0.015	531	448
		X70	0.22	1.65	0.025	0.015	565	483
		X80	0.22	1.85	0.025	0.015	621	552

Structural Steel Pipe Introduction

Structural Steel Pipe can accommodate many different applications including bollards and bumper posts, structural columns, shoring, fencing, piling, racks and rollers. Structural Steel Pipe mainly used for factories, bridges, ships and other structures. Structure Steel Pipe includes various seamless steel pipe or welded steel pipe for structure, pile pipe, large diameter seamless steel pipe, large diameter submerged arc welded steel pipe, large diameter seamless steel pipe, large diameter thick wall thickness steel pipe etc. 

STANDARD:

Chinese National Standard: GB/T8162 

American Society for Testing and Materials Standard: ASTM A53

American Boiler and Pressure Vessel Code: ASME SA53

STEEL GRADE: 10 ,20 ,35, 45, Q345, 15CrMo, 12Cr1MoV, A53A, A53B, SA53A, SA53B

Seamless Steel Pipe for Structure:

Seamless Steel Pipe for Structure is used seamless steel pipes or seamless steel tubes for general structure and mechanical structure. For the manufacturer of pipes, containers, 

equipment, fittings and mechanical structure seamless steel pipe. 

Specification: 

Outside Diameter: 10.3mm ~ 1013mm

Wall Thickness: 1.7mm ~ 52mm

Welded Steel Pipe for Structure:

Welded steel pipe used in steel structures, bridges, support, building structure pipe, pile pipe. Since the structure steel pipe or structure steel tube requires a lot of pressure. 

Structural steel pipe requires high pressure capabilities which means only the steel pipes has greater wall thickness (> 8mm) can be applied as structure steel pipe. 

Type of Pipes:

1. LSAW Steel Pipe - Logitudinal Submerged Arc Welded Steel Pipe

2. SSAW Steel Pipe - Spiral Submerged Arc Welded Steel Pipe

3. SAWH Steel Pipe - Submerged Arc Welded Helical Steel Pipe

Specification:

LSAW Steel Pipe: Outside Diameter: 406mm ~ 1625mm, Wall Thickness: 6.0mm ~ 75mm

SSAW Steel Pipe/SAWH Steel Pipe: Outside Diameter: 219mm ~ 4064mm, Wall Thickness: 3.2mm ~ 40mm

Galvanized Steel Pipe Production Process

Galvanized Steel PipeIn order to improve the corrosion resistance of the steel pipe, in general people will coated the steel pipe with zinc. Galvanized steel pipe is mainly used for transporting gas and heating.
If use galvanized steel pipe as water pipes for drinkable water, after many years of application, it turns out there are many rust inside the steel pipe which will influence the quality of the
drinking water.


Galvanized Steel Pipe Weight Formula: ( Outside Diameter - Wall Thickness) x Wall Thickness x 0.02466 * 1.0599 = Weight per Meter (kg / m)

There are two types of galvanized steel pipe in the market which is divided by the production processes.

Hot-dipped Galvanized Steel Pipe:

Hot-dipped zinc coating is the molten metal to react with the iron matrix alloy layer. So the substrate and the zinc coating combined well. The first production step is pickling the steel pipe.
In order to remove the surface of the iron oxide, cleaning bath by mixing an aqueous solution of ammonium chloride or zinc chloride aqueous solution for the after pickling steel pipe is
needed. And then the steel pipe is allowed to put in the hot dip tank. The using advantage for hot dipped galvanized steel pipe is the coating has strong adhesion and long using life.
Applying hot-dipped galvanizing process, the zinc coating will be combined with the surface of the steel pipe evenly.

Production Process:

Material Inspection (Steel Pipe) --- Hanging --- De-greasing --- Rinsing --- Pickling --- Washing --- Dipping Fluxing --- Hot Air Drying --- Inside and Outside Hot-dipped Galvanizing Blow
--- Cooling --- Passivation and Rising --- Unloading --- Inspection and Trimming --- Type Identification --- Packaging and Storing and Transportation.



Cold Galvanized Steel Pipe:

Cold Galvanizing process is also named as electro-galvanizing process which is using cold plates as raw material. Cold Galvanized Steel Pipe has very few zinc coating which is only around
10 ~ 50 g/m2. Compared with hot-dipped galvanized steel pipe, the corrosion resistance of cold galvanized steel pipe is not as good as hot-dipped galvanized steel pipe.
In order to ensure the quality of the galvanized steel pipe, most of the galvanized steel pipe manufacturers will not apply the electro galvanizing producing process. Only those small and
outdated manufacturers still use electro-galvanizing producing process to offer relatively cheaper galvanized steel pipe. Since the zinc layer for cold galvanized steel pipe is electroplated layer,
it is the individual layered zinc coating on the steel pipe, so the coating layer will be peel off easily. Overall, the producing cost for cold galvanized steel pipe is lower than hot-dipped
galvanized steel pipe, and the manufacturer can offer the purchaser a very competitive market price. However, the surface of the coating is uneven which influence the corrosion resistance
of the galvanized steel pipe.

Production Process:

Uncoiling (Galvanized Steel Strips/Plates) --- Leveling --- Welding --- Scraping the Scar --- Passivation and Rinsing --- Zinc adding --- Setting/Forming --- Type Identification --- Cutting
--- Packing --- Drying --- Weighed

Anti-corrosion Steel Pipe

Anti-corrosion Steel Pipe apply anti-corrosion processing technology to prevent or mitigate the steel pipe corrosion phenomena during the transport and use of the pipes. Anti-corrosion steel pipe mainly used in pipeline projects in petroleum, chemical, natural gas, heating, sewage treatment, water, bridges area. These type of pipes is widely applied to anti-corrosive steel marine facilities, petrochemical, industrial and mining enterprises in the construction industry, various types of tanks, transport pipeline.

Anti-corrosion Coating
There are many categories of corrosion media for bare steel pipe, such as acid, alkali, salt, oxidants and water vapor. The coating of steel pipe must be chemically inert, acid salt corrosion, structure compact, waterproof permeability, adhesion, tough fullness.

FBE Anti-corrosive Coating
Apply electrostatic spraying technology to coat epoxy powder at the surface of steel pipe. This technology will be applied once and finish a complete coating at the surface of the steel pipe. The coating operation process is simple, environment friendly, good coating impact resistance and flexural properties, temperature resistance advantages. FBE anti-corrosion coating is a new type of coating developed in the last 30 years.

Specification: Outside Diameters: 89mm~1820mm, Wall Thickness: 6mm~20mm
Material: Q235B, Q345B, 10#STEEL, 20#STEEL, X42~X80 etc.
Application: Widely used in oil pipelines, gas pipelines, heating pipes, water pipes.
Executive Standard: API 5L, GB / T9711-2011, DIN30670, DIN30671, SY / T0413-2002, SY / T0315-97, GB / T23257-2009, SY / T0447-96, SY / T0457-2008, CECS10: 89, CJ / T114-2000, CJ / T115-2001, CJ / T200-2004, GB / T29047-2012, SY / T4054-2003, CJ / T120-2008, etc.

2PE/3PE Anti-corrosion Coating
2/3PE anti-corrosion coating steel pipe is the type of steel pipe coated with three layered structure of polyolefin coating (MAPEC). 2/3 PE anti-corrosion coated steel pipe is commonly used as a preservative pipeline. Applying electrostatic spraying epoxy power at the surface of the steel pipe first, then apply lateral wound adhesive and lateral wound polyethylene coating at the steel pipe. Combined with three excellent performance to improves the overall quality of pipeline corrosion. The advantage of the coating is resistant to chemical corrosion, cathodic stripping, resistance to mechanical damage performance.

3PE anti-corrosive coating is generally consists of three layers.
1) the first layer of mixed epoxy powder (FBE >100um).
2) the second layer of adhesive (AD: 170um ~ 250um).
3) the third layer of polyethylene (PE: 2.5mm ~ 3.7mm).
In actual operation, these three kinds of materials will combined after the processing and formed a solid excellent anti-corrosion layer. The processing methods are generally divided in two and wound sheathed round mold.

Domestic implementation standard for 3PE anti-corrosion coated steel pipe is SY/T0413-2002 which is effect implementation from August 1, 2002. This standard mainly specify polyethylene and high-density polyethylene-based. The thickness of the outer coating is specified under the German Standards DIN 30670-1991. This standard is greatly improved the impact strength of 3PE anti-corrosion coating. Under this standard, the peel strength and impact indicators will significantly improved and clearly defined for 3PE anti-corrosion coated steel pipe. Also, this standard has defined the carbon black content for some special materials which is increased the mending peel strength ( ie. thermal units, the peel strength of the primer steel thermal band) frequency sampling tests.

Why Need Tempering for Producing Pipeline?

Pipeline
API SPEC 5L-2011 (Pipeline Specification) is the American Petroleum Institute published pipeline standard used allover the world. Pipeline is used to extract oil, gas or water to the ground and transport to the oil and gas industry. Pipeline include seamless line pipe and welded line pipe, the pipe end can be threaded end, socket end, plain end, beveled end. The connection type for the pipe can be tip welding, coupling connection, socket connection.

Tempering Process for Producing Pipeline
According to different performance requirements for pipeline, there are three different types of tempering temperature categories:
​
1)Low Temperature Tempering (150 to 250 degrees)
The result of Low Temperature Tempering is Tempered Martensite. The goal is to keep the high hardness and high ware resistance of the steel, and at the same time to reduce the quenching stress and fragility. This producing process can avoid cracking or premature failure when apply the pipeline. After Low Temperature Tempering, the hardness is generally HRC58-64.

2)Medium Temperature Tempering
The result of Medium Temperature Tempering is Tempered Troostite. The goal is to obtain high yield strength, high toughness, and high elastic limit. It is mainly used for various pipes, after the Medium Temperature Tempering, the tempering hardness is generally HRC35-50.

3)High Temperature Tempering
The result of High Temperature Tempering is Tempered Sorbite. In general, High Temperature Tempering will be applied together with Heat Treatment, and we call these two processing technology as Quenching. The goal for High Temperature Tempering is to obtain high strength, hardness and ductility. These improving will increase the overall mechanical properties of pipeline. This technology is widely used for manufacturing automotive, pipeline, machine tools and other important structural parts. After the High Temperature Tempering, the hardness is generally HB200-330.

What is the technical advantages of tempering?

Tempering is a metal treatment process. After hardening, the meal piece need to re-heating to an appropriate temperature, hold this temperature degree for a while, and then slowly or rapidly cooled. Generally, tempering is used to reduce or eliminate the stress of hardened steel, or to reduce its hardness and strength, to improve ductility or toughness. According to different requirements for the meal piece, there are three different types of tempering which are Low Temperature Tempering, Medium Temperature Tempering, High Temperature Tempering. When increasing the temperature of tempering, the hardness and strength decreased, the ductility or toughness increased gradually.

The characteristic after tempering including:
1.Got martensite, bainite, residual austenite unbalanced ( ie instability) organization.
2.Bigger internal stress
3.After quenching, the mechanical properties of the metal piece can not meet the requirements. Therefore, tempering is necessary to improve the organizational stability and enhance the mechanical properties.

Do you know The difference between Annealing and Tempering?

Annealing and Tempering are production process for steel pipes. Do you know the difference between Annealing and Tempering?

Annealing is applied to a variety of metal processing, the main effect of annealing is to soften the metal and strengthen toughness. Annealing of steel is used in the production of preliminary heat treatment process. Most of machine parts or metal pieces, after rough mold annealed, it can eliminate casting, tissue inhomogeneity stress and forging components and weldments. Beiseds, annealing can improve and adjust the mechanical properties of steel, it make sure the metal piece is ready for the next process organization and preparation. For those less important parts, less demanding performance, some ordinary castings, weldments, annealing can be used as the final heat treatment. Annealed steel is the steel which is heated to a suitable temperature, and holding a certain time, and then slowly cooled to get close to equilibrium tissue heat treatment process. Annealing aims to uniform chemical composition, mechanical properties and improved process performance, eliminate or reduce stress and prepare the organization for the part to prepare the final heat treatment.


However, tempering is mainly used in steel hardening after reducing brittleness. Steel Tempering is to heated the steel to a certain temperature for certain time, and then cool the steel to room temperature by appropriate manner. In general, it will be applied after hardening heat treatment process. Tempering will decide the steel micro structure and properties during the application. Also, it is a key step to decide the using time of the work piece. The main purpose of tempering is to reduce or eliminate quenching stress, and ensure appropriate organizational changes. Moreover, tempering will improve thermal resistance and ductility of the steel. In order to meet the performance requirements of different metal parts, it is necessary to choose a different tempering temperature to obtain a good hardness, strength, ductility and toughness combination.

Oversea Clients Visiting Continued in Shinestar Holdings Group

In order to keep maintaining good relationship with our international clients, Shinestar Holdings Group continued to visiting clients oversea. During this visiting trip to Australia, Vietnam and Turkey, we received timely feedback from our clients, and will be a good opportunity to improve our services. In the next year, Shinestar Holdings Group will keep visiting our clients in Singapore, Brazil, Mexico, New Zealand, South Africa, Qatar, Jordan, Nigeria and other countries. 

The different types of annealing process.

Annealing is a heat treatment process for metal, slowly heated the metal to a certain temperature and maintain a sufficient time, and then cooling at an appropriate rate. The purpose for annealing is to improve or eliminate defects in various tissues and prevent deformation of the work piece or cracking. Also, annealing can be used for softening the metal for machining. Besides, it helps to grain refinement to improve the organization in order to improve the mechanical properties of the work piece. It is the preparation process for the final heat treatment (quenching and tempering).

There are different types of annealing process, these process are:

1.Fully Annealing (For refinement and low carbon steel). During the steel casing, forging and welding, the steel appreas poor mechanical properties. During fully annealing, the steel work piece is heated to a temperature above 30~50 degree, and then all the ferrite turn into austenite. Holding for some time, and then slowly cooled with the furnace. In the cooling process, austenite transformed again which make the steel organization thinner.

2.Ball Annealing. In order to reduce the high hardness of the steel after forging. The work piece is heated to a temperature between 20 to 40 degrees which the steel of austenite begins to form, and then slowly cooling after incubation. During the cooling, the lamellarpearlite cementite becomes spherical which will reduces the hardness of the steel.

3.Isothermal Annealing. In order to reduce the high hardness, high chromium content and some nickel content alloy structural steel before cutting, Isothermal Annealing is necessary. First, cooled the steel at a faster rate to the most unstable austenite temperature, and then hold the temperature for a appropriate time. In the last, the austenite turned into sorbite prop’s body which can reduce the hardness of the steel.

4.Re-crystalization Annealing. The purpose for re-crystalization annealing is to eliminate metal wire and sheet metal hardness during the cold drawing or cold rolling process (hardness increased plasticity decrease) . The heating temperature is generally between 50~150 degree which the austenitic begins to form. This is the only way to eliminate the effect of hardening and make the steel softened.

5.Graphitization Annealing. To make the cast iron contains a lot of cementite into plastic good malleable iron. The casting process operation is heated to about 950 degree. Before cooling needed to hold to a certain temperature for a certain time. In the end, the cementite decomposes to form group flocculent graphite.

6.Diffusion Annealing. It is applied on alloy castings fro the chemical composition uniformity and improves its performance. The method is applied when the meting does not occure under the premise, the casting is heated to a temperature as high as possible, and prolonged heat until alloy of various elements diffusion after slow cooling more uniform distribution.



7.Stress Relief Annealing. The purpose of Stress Relief Annealing is to eliminate the stress of steel castings and weldments. After the start of heating for the formation of austenite steel prodcuts below the temperature 100 to 200 degree and after holding cooling in the air for a certain time, you can eliminate stress of the steel.

For more information, please read What is Quenching?

What is Quenching?

Quenching is the heat treatment process applied on metal. Heated the metal to a suitable temperature and hold for a certain time, then immersed in quenching medium and cooled immediately. In general, saline, water, mineral oil, air can be used as quenching medium. Quenching process is widely used in various engineering, mold, measuring tools and requirements of surface wear of parts ( such as gears, rollers, carburizing parts ect.). Because quenching can increase the hardness and wear resistance of metal parts. Quenching process has been widely used in modern machinery manufacturing industry. For those important mechanical parts, especially the metal parts applied on automotive, aircraft, rockets.

Generally, quenching and tempering will be applied together on the metal, by quenching and tempering with different temperatures can greatly improve the strength of the metal, fell toughness and fatigue strength, and to get fit ( mechanical properties) between the performance of these to meet different requirements. Further hardening can also make some special properties of steel to obtain certain physical and chemical properties, such as hardened steel reinforcing its permanent magnet ferromagnetic stainless steel to improve its corrosion resistance.

Quenching process is mainly used for steel parts, when steel heated to above the critical temperature, the original organization of steel turned into austenite ( all or most of). Then the steel will be immersed in water or oil rapidly cooling, and the austenite turned into martensite. Compared with other organizations in steel, martensite has highest hardness. Rapid quenching cooling causes internal stress generated. When it to a certain extent, the steel might be distortion or cracking. Therefore, the right method of cooling is significant.

For more manufacturing news, please read What is Annealing?, What is Tempering?, The difference between Annealing and Tempering

The Application for Boiler Tube You Must Know

Boiler Tube is a kind of steel pipe which can be divided into seamless and welded steel pipe by producing process. The specification range for boiler tube is very wide, it covers from small diameter pipe to large diameter pipe with vary pipe length. Depending on the temperature level, boiler tube can be divided into general type boiler tube and high pressure boiler tube. In Shinestar, our factory can produce different types of boiler tube based on the use requirements. 

Boiler Tube Weight Formular:

[(OD - Wall Thickness) * Thickness] * 0.02466 = kg / m (weight per meter)

Boiler tube can be used for transmission pipe, thermal equipment, industrial petroleum geology exploration, container, chemical industry and special purposes. Also, it can be used to make water wall tube, boiling water pipe, superheated steam pipes, superheated steam locomotive boiler tubes, and large or small funnels and arch brick pipe. For high pressure boiler tube is mainly used to manfuacture high and altra-high pressure boiler superheater tubes, reheater tube, airway, and steam pipe. High pressure boiler tubehas stable supply and demand trend in the whole boiler tube industry. In the future, the high pressure boiler tube industry will be further differentiation. High pressure boiler tube will be widely promoted due to its new energy saving advantages. 

Mechanical properties of the boiler tube is the important indicator to ensure the end use properties. In the steel standard, according to different requirements, the provisions of the tensile properties (tensile strength, yield strength or yield point elongation) and hardness, toughness index, as well as user requirements of high and low temeprature properties. General, boiler tube is used in the temperature below 305 degree, so our boiler tube is manufactured by hot rolled or cold drawn steel tube. High pressure boiler tubes is often used in the high temperature and high pressure conditions for transmission gas and steam. In order to avoid oxidation and corrosion, boiler tubes require durable steel with high strength, high oxidation resistance, and good organization stability. 

For more information about boiler tube, please read ASTM A106 Pressure Pipe

What is High Pressure Boiler Tube?

 

High pressure boiler tube is one kind of seamless steel pipe. The manufacturing mehod of high pressure boiler tube is the same as other type of seamless steel pipe. However, the steel materials used for high pressure boiler tube has strict requirements. High pressure boiler tube often used in high temeprature and high pressure condition. The pipes is often under the condition of high temperature gas and water vapor, would oxidation and corrosion. Therefore, high pressure boiler tubes require durable steel with high strength, high oxidation resistance, and have good organizational stability. High pressure boiler tube is mainly used to manufacture high and ultra-high pressure boiler superheater tubes, reheater tube, airway, steam pipe etc.

When high pressure boiler seamlss steel tubes use hot rolled manufacturing process, and the outside diameter of the tubes ranges from 22m to 530mm, and the wall thickness of the tubes ranges from 20mm to 70mm. If the manufacturing process is cold drawn, the specification of outside diameter ranges from 10mm to 108mm, wall thickness ranges from 2.0mm to 13.0mm.



For more information, please read Boiler Tubes.