Introduction And Classification Of Alloy Pipe

1. Introduction of alloy pipe

Alloy pipe is a kind of seamless steel pipe. Alloy pipe is divided into seamless pipe for structure and high pressure heat-resistant alloy pipe. It is mainly different from the production standard of alloy tube and its industry. Annealing and tempering the alloy tube changes its mechanical properties. Achieve the required processing conditions. Its performance is higher than that of ordinary seamless steel pipes. The chemical composition of alloy pipes contains more Cr, and it has high temperature resistance, low temperature resistance and corrosion resistance. Common carbon seamless pipes do not contain alloy components or have very few alloy components. The reason why alloy pipes are widely used in petroleum, aerospace, chemical, electric power, boiler, military and other industries is that the mechanical properties of alloy pipes are changed and adjusted.

1.1 Implementation standards for seamless pipes

China National Standard

GB/T8162-2018

GB/T8163-2018

GB/T3087-2018

GB/T6479-2018

GB/T9948-2018

GB/T5310-2018

ASME SA210-American Boiler and Pressure Vessel Code

ASME SA213-American Boiler and Pressure Vessel Code

DIN17175-Federal German Industrial Standard

 1.2 Calculation of alloy management theory:

(Outer diameter-wall thickness) * wall thickness * 0.02483 = weight per meter.

1.3 Material classification of alloy tubes

The material of the alloy tube is roughly: 16-50Mn, 27SiMn, 20-40Cr, 12-42CrMo

16Mn 12Cr1MoV T91 27SiMn 30CrMo 15CrMo 20G Cr9Mo 10CrMo910 15Mo3 15CrMoV 35CrMoV 45CrMo

2. Classification of alloy tubes

(1) Seamless steel pipe

Because of their different manufacturing processes, they are divided into two types: hot-rolled (extruded) seamless steel pipes and cold-drawn (rolled) seamless steel pipes. Cold drawn (rolled) tubes are divided into two types: round tubes and special-shaped tubes.

a. Process overview

Hot rolling (extruded seamless steel tube): round tube billet heating and piercing three-roll cross-rolling, continuous rolling or extruding, sizing (or reducing), cooling billet straightening water pressure test (or flaw detection) mark and put into storage.

Cold drawn (rolled) seamless steel pipes: round pipe billets are heated, perforated, headed, annealed, pickled, and oiled (copper-plated).

b. Seamless steel pipes are divided into the following varieties due to their different uses:

GB/T8162-2008 (Seamless steel pipe for structure). Mainly used for general structure and mechanical structure. Its representative materials (brands): carbon steel 20, 45 steel; alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35CrMo, 42CrMo, etc.

GB/T8163-2008 (Seamless steel pipe for conveying fluid). Mainly used in engineering and large-scale equipment to transport fluid pipelines. The representative material (brand) is 20, Q345, etc.

GB3087-2008 (Seamless steel pipes for low and medium pressure boilers). Mainly used in industrial boilers and domestic boilers to transport low and medium pressure fluid pipelines. Representative materials are 10 and 20 steel.

GB5310-2008 (Seamless steel tubes for high-pressure boilers). Mainly used for high-temperature and high-pressure conveying fluid headers and pipelines on boilers in power plants and nuclear power plants. Representative materials are 20G, 12Cr1MoVG, 15CrMoG, etc.

GB5312-1999 (Carbon steel and carbon-manganese steel seamless steel pipes for ships). Mainly used for I and II pressure pipes for marine boilers and superheaters. Representative materials are 360, 410, 460 steel grades, etc.

GB6479-2000 (Seamless steel pipes for high-pressure fertilizer equipment). Mainly used for conveying high temperature and high pressure fluid pipelines on fertilizer equipment. Representative materials are 20, 16Mn, 12CrMo, 12Cr2Mo, etc.

GB9948-2006 (Seamless steel pipe for petroleum cracking). Mainly used in boilers, heat exchangers and fluid pipelines of petroleum smelters. Its representative materials are 20, 12CrMo, 1Cr5Mo, 1Cr19Ni11Nb, etc.

GB18248-2000 (Seamless steel tubes for gas cylinders). Mainly used to make various gas and hydraulic cylinders. Its representative materials are 37Mn, 34Mn2V, 35CrMo, etc.

GB/T17396-2007 (Hot-rolled seamless steel pipe for hydraulic props). Mainly used to make coal mine hydraulic supports, cylinders and columns, and other hydraulic cylinders and columns. Its representative materials are 20, 45, 27SiMn and so on.

GB3093-1986 (High-pressure seamless steel pipes for diesel engines). Mainly used for high pressure oil pipe of diesel engine injection system. The steel pipe is generally cold drawn, and its representative material is 20A.

GB/T3639-2007 (cold drawn or cold rolled precision seamless steel pipe). It is mainly used for steel pipes for mechanical structures and carbon pressure equipment that require high dimensional accuracy and good surface finish. Its representative materials are 20, 45 steel, etc.

GB/T3094-1999 (cold drawn seamless steel pipe special-shaped steel pipe). It is mainly used to make various structural parts and parts, and its materials are high-quality carbon structural steel and low-alloy structural steel.

GB/T8713-1988 (Precision inner diameter seamless steel pipe for hydraulic and pneumatic cylinders). Mainly used to make cold drawn or cold rolled seamless steel pipes with precise inner diameters for hydraulic and pneumatic cylinders. Its representative materials are 20, 45 steel, etc.

GB13296-2007 (Stainless steel seamless steel tubes for boilers and heat exchangers). Mainly used in boilers, superheaters, heat exchangers, condensers, catalytic tubes, etc. of chemical enterprises. Used high-temperature, high-pressure, corrosion-resistant steel pipe. Its representative materials are 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti, etc.

GB/T14975-2002 (Stainless steel seamless steel pipe for structure). It is mainly used for general structure (hotel and restaurant decoration) and mechanical structure of chemical enterprises, which are resistant to atmospheric and acid corrosion and have certain strength steel pipes. Its representative materials are 0-3Cr13, 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti, etc.

GB/T14976-2002 (Stainless steel seamless steel pipe for fluid transportation). Mainly used for pipelines that transport corrosive media. Representative materials are 0Cr13, 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr17Ni12Mo2, 0Cr18Ni12Mo2Ti, etc.

YB/T5035-1993 (Seamless steel pipes for automobile axle sleeves). It is mainly used to make high-quality carbon structural steel and alloy structural steel hot-rolled seamless steel pipes for automobile half-axle sleeves and axle tubes of drive axle housings. Its representative materials are 45, 45Mn2, 40Cr, 20CrNi3A, etc.

API SPEC5CT-1999 (Casing and Tubing Specification) is compiled and published by the American Petroleum Institute (American Petreleum Instiute, referred to as “API”) and used in all parts of the world. Among them: Casing: the pipe that extends from the ground surface into the well and serves as the lining of the well wall. The pipes are connected by couplings. The main materials are steel grades such as J55, N80, and P110, and steel grades such as C90 and T95 that are resistant to hydrogen sulfide corrosion. Its low steel grade (J55, N80) can be welded steel pipe. Tubing: A pipe inserted into the casing from the ground surface to the oil layer, and the pipes are connected by couplings or integrally. The role of the pumping unit is to transport the oil from the oil layer to the ground through the oil pipe. The main materials are steel grades such as J55, N80, P110, and C90, T95 that are resistant to hydrogen sulfide corrosion. Its low steel grade (J55, N80) can be welded steel pipe.

API SPEC 5L-2000 (line pipe specification), compiled and issued by the American Petroleum Institute, is commonly used all over the world.

Line pipe: It transports the oil, gas or water out of the ground through the line pipe to the petroleum and natural gas industrial enterprises. Line pipes include seamless pipes and welded pipes. The pipe ends have flat ends, threaded ends and socket ends; the connection methods are end welding, coupling connection, socket connection, etc. The main material of the tube is B, X42, X56, X65, X70 and other steel grades.

3. Use classification of alloy tube

Size and allowable deviation table

Deviation level	Allowable deviation of standardized outer diameter
D1	±1.5%，min±0.75 mm
D2	±1.0%。min±0.50 mm
D3	±0.75%．min±0.30 mm
D4	±0.50%。min±0.10 mm

Alloy tubes are mainly used for heating surface tubes of low and medium pressure boilers (working pressure generally not greater than 5.88Mpa, working temperature below 450℃); for high-pressure boilers (working pressure generally above 9.8Mpa, working temperature between 450℃～650 ℃) heating surface pipe, economizer, superheater, reheater, petrochemical industry pipe, etc.

High-pressure alloy pipe grades: 15CrMoG, 12Cr2MoG, 12Cr1MoVG, 12Cr2MoWVTiB, 10Cr9Mo1VNb, SA210A1, SA210C, SA213 T11, SA213 T12, SA213 T22, SA213 T23, SA213 T91, SA213 T92, ST45.8/Ⅲ, 15Mo10, 13CrMo44, etc.

4. Alloy specification table

Wall thickness

Unit: Kg/m
Wall thickness	3	3.5	4	4.5	5	5.5	6
32	2.146	2.460	2.762	3.052	3.329	3.594	3.847
38	2.589	2.978	3.354	3.718	4.069	4.408	4.735
42	2.885	3.323	3.749	4.162	4.562	4.951	5.327
45	3.107	3.582	4.044	4.495	4.932	5.358	5.771
50	3.477	4.014	4.538	5.049	5.549	6.036	6.511
54	3.773	4.359	4.932	5.493	6.042	6.578	7.103
57	3.995	4.618	5.228	5.826	6.412	6.985	7.546
60	4.217	4.877	5.524	6.159	6.782	7.392	7.990
63.5	4.476	5.179	5.869	6.548	7.214	7.867	8.508
68	4.809	5.567	6.313	7.047	7.768	8.477	9.174
70	4.957	5.740	6.511	7.269	8.015	8.749	9.470
73	5.179	5.999	6.807	7.602	8.385	9.156	9.914
76	5.401	6.258	7.103	7.935	8.755	9.563	10.358
89	6.363	7.380	8.385	9.378	10.358	11.326	12.281
108	7.768	9.020	10.259	11.486	12.701	13.903	15.093
133	11.178	12.725	14.261	15.783	17.294	18.792
159	13.422	15.290	17.146	18.989	20.821	22.639
219	18.601	21.209	23.805	26.388	28.959	31.517
273	23.262	26.536	29.797	33.046	36.283	39.508
325	27.750	31.665	35.568	39.458	43.337	47.202
355	38.897	43.158	47.406	51.641
377	41.339	45.871	50.390	54.897
426	46.777	51.913	57.036	62.147
450
480
530
630
Unit: Kg/m
Wall thickness	6.5	7	8	8.5	9	10	12
32	4.088
38	5.049
42	5.691
45	6.172
50	6.973	7.423	8.286	8.699
54	7.614	8.114	9.075	9.538
57	8.095	8.632	9.667	10.167
60	8.576	9.149	10.259	10.796
63.5	9.137	9.754	10.950	11.529
68	9.858	10.530	11.838	12.473
70	10.179	10.876	12.232	12.892	13.539	14.797	17.164
73	10.660	11.394	12.824	13.521	14.205	15.537	18.052
76	11.141	11.912	13.416	14.150	14.871	16.277	18.940
89	13.225	14.156	15.981	16.875	17.756	19.483	22.787
108	16.270	17.436	19.729	20.858	21.973	24.168	28.410
133	20.278	21.751	24.662	26.098	27.522	30.334	35.809
159	24.446	26.240	29.791	31.548	33.293	36.746	43.503
219	34.064	36.598	41.629	44.126	46.610	51.543	61.259
273	42.720	45.920	52.283	55.445	58.596	64.860	77.240
325	51.056	54.897	62.542	66.346	70.137	77.684	92.629
355	55.865	60.076	68.460	72.634	76.796	85.082	101.507
377	59.391	63.873	72.801	77.246	81.679	90.508	108.018
426	67.246	72.332	82.468	87.518	92.555	102.592	122.519
450	71.093	76.475	87.203	92.549	97.882	108.511	129.621
480	75.902	81.654	93.122	98.837	104.540	115.909	138.499
530	83.917	90.286	102.987	109.319	115.638	128.240	153.296
630	99.947	107.549	122.716	130.281	137.833	152.902	182

16Mn Specification Table

Specification	Specification	Specification	Specification	Specification	Specification
406*16	457*32	508*80	530*22	660*80	820*55
406*17	457*35	508*90	530*25	660*90	820*60
406*18	457*40	508*100	530*28	660*100	820*70
406*19	457*45	530*16	610*30	660*150	820*80
406*20	457*50	530*17	610*32	710*20	820*90
406*22	457*55	530*18	610*35	710*22	820*100
406*25	457*60	530*19	610*40	710*25	820*150
406*28	457*65	530*20	610*45	710*28	820*200
406*30	457*70	530*22	610*50	710*30	864*40
406*32	457*80	530*25	610*55	710*32	864*55
406*35	457*90	530*28	610*60	710*35	864*60
406*40	457*100	530*30	610*65	710*40	864*70
406*45	480*16	530*32	610*70	710*45	864*80
406*50	480*17	530*35	610*80	710*50	864*90
406*55	480*18	530*40	610*90	710*55	864*100
406*60	480*19	530*45	610*100	710*60	864*150
406*65	480*20	530*50	610*150	710*65	864*200
406*70	480*22	530*55	630*18	710*70	900*60
406*80	480*25	530*60	630*19	710*80	900*70
406*90	480*28	530*65	630*20	710*90	900*80
426*16	480*30	530*70	630*22	710*100	900*90
426*17	480*32	530*80	630*25	710*150	900*100
426*18	480*35	530*90	630*28	720*25	900*150

5. Alloy steel pipe

5.1 Uses of alloy steel pipes

The main purpose of alloy steel pipe is to use high-pressure and high-temperature pipelines and equipment such as power plants, nuclear power, high-pressure boilers, high-temperature superheaters and reheaters. It is made of high-quality carbon steel, alloy structural steel and stainless heat-resistant steel. , After hot rolling (extruding, expanding) or cold rolling (drawing).

5.2 Advantages of alloy steel pipe

It can be recycled 100%, in line with the national strategy of environmental protection, energy saving, and resource saving. The national policy encourages the expansion of the application fields of high-pressure alloy pipes. In my country, the consumption of alloy pipes accounts for only half of the total amount of steel in developed countries. The expansion of the use of alloy pipes provides a broader space for the development of the industry. According to the research conducted by the expert group of the Alloy Pipe Branch of the China Special Steel Association, in the future, the demand for high-pressure alloy pipe and long products in my country will increase by 10-12% annually.

5.3 The connection and difference between alloy steel pipe and seamless pipe

Alloy pipe is defined by steel pipe according to the production material (that is, material), as the name suggests, is pipe made of alloy; while seamless pipe is defined by steel pipe according to the production process (seamless and seamless), the difference from seamless pipe is Seam pipes, including straight seam welded pipes and spiral welded pipes.

5.4 Alloy steel pipe standard

Alloy pipes have a hollow section and are used in large quantities as pipelines for conveying fluids, such as pipelines for conveying oil, natural gas, gas, water, mechanical processing, and certain solid materials. Compared with solid steel such as round steel, alloy steel pipe is lighter when the bending and torsion strength is the same. Alloy steel pipe is a kind of economical cross-section steel, which is widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipes and automobile transmission. Axes, bicycle frames and steel scaffolding used in building construction, etc. The use of alloy steel pipes to manufacture ring-shaped parts can improve material utilization, simplify manufacturing procedures, save materials and processing man-hours, such as rolling bearing rings, jack sleeves, etc., which have been widely used for manufacturing steel pipes. Alloy steel pipes are also an indispensable material for various conventional weapons. Gun barrels and barrels are all made of steel pipes. Alloy steel pipes can be divided into round pipes and special-shaped pipes according to different cross-sectional area shapes. Since the circle area is the largest under the condition of the same circumference, more fluid can be transported with a circular tube. In addition, when the ring section bears internal or external radial pressure, the force is relatively uniform. Therefore, most steel pipes are round pipes.

Alloy pipes include large-diameter alloy pipes, thick-walled alloy pipes, high-pressure alloy pipes, alloy flanges, alloy elbows, P91 alloy pipes and seamless steel pipes. In addition, special fertilizer pipes are also very common.

HSH stocks a broad range of metal materials, including aluminum, steel, stainless steel, copper and brass, and specialty metals. Also, we also sell cast fittings, cast Iron, forged fittings, cutting tools, flanges, ect. If you have any needs or questions, you can contact us.
sales@metal-pipe.com