NH1949 Anti coking New Materials

Low Carbon Efficiency Enhancement · Supporting High Quality Development

Products

Cracking Furnace Tube

Reformer Tube

DRI

NH1949 Anti coking New Materials

3D Digital Three-dimensional Bending Technology

Steam Superheater Tube

Static Castings

Industry Development Background

In the ethylene cracking unit, coking in the cracking furnace is a major issue affecting the long-term operation of the ethylene unit. Domestic ethylene production enterprises widely use heat-resistant alloy ethylene cracking furnace tubes, which have a high tendency for coking, short coke cleaning cycles, high energy consumption, high production costs, low efficiency, and seriously affect product quality and the environment.

Coking

increases wall thermal resistance and energy consumption; The inner diameter of the furnace tube decreases, resulting in a decrease in output; Cleaning coke reduces production period and emits a large amount of CO and gas.

Carburization

The formation of a large amount of carbides reduces the plasticity and creep performance of the furnace tube. When the carburized layer reaches 60% of the wall thickness, the furnace tube is judged as scrap.

Industry Pain Points

Increased Energy Consumption

Decreased Yield of Ethylene Products

Unit Cost Increase

Reduced Service Life of Furnace Tubes

Increased Air Pollution

NH1949 Anti coking New Materials emerged

Since 2012, we have independently developed a new generation of high-temperature alloy ethylene cracking furnace tubes. By adding AI elements to generate a stable AL2 oxide film, as well as solid solution strengthening and grain boundary purification of W elements and rare precious metal elements, we can automatically form a layer of AL203 oxide film with uniform density and high thermal stability in high-temperature environments, ensuring that the alloy has excellent oxidation resistance, anti carburization and anti coking properties; Adding an appropriate amount of W to gold for solid solution strengthening ensures that the alloy maintains excellent high-temperature mechanical properties at temperatures above 1100 ℃.

Invented NH1949 high-temperature alloy, an aluminum furnace tube material with excellent mechanical properties, anti carburization and anti coking properties. The preparation of NH1949 alloy furnace tubes and static castings with high metallurgical quality and service performance ensures that the NH1949 alloy products leaving the factory have excellent mechanical properties, anti carburization and anti coking properties, which can significantly prolong the coke cleaning cycle of cracking furnace tubes in ethylene production, improve production efficiency, and increase service life.

Chemical Composition

Qingdao NPA industry Co,.Ltd	Material Data Sheet NH1949	Doc. No: NH199 Rev.: 00
Element	Mini-Max	Remarks
C	0.40-0.55
Cr	25.0-29.0
Ni	43.0-47.0
AI	3.0-4.5
W	4.0-6.0
Microalloy	addition
Iron	Balance

Qingdao NPA industry Co,.Ltd	Material Data Sheet NH1949	Doc. No: NH199 Rev.: 00
Element	Mini-Max	Remarks
C	0.40-0.55
Cr	25.0-29.0
Ni	43.0-47.0
AI	3.0-4.5
W	4.0-6.0
Microalloy	addition
Iron	Balance

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Physical Properties

Items	Density (Kg/dm3)	Coefficlent of expansion(10-6/℃)			Modulus of elasticity (GPa)			Thermal Conductivity (W/M · k)
Items	Density (Kg/dm3)	20-900℃	~1000℃	~1100℃	900℃	1000℃	1100℃	900℃	1000℃	1100℃
Value	7.8	17.68	18.0	19.15	129	116	103	20.4	22.3	23.8

Items	Density (Kg/dm3)	Coefficlent of expansion(10-6/℃)			Modulus of elasticity (GPa)			Thermal Conductivity (W/M · k)
Items	Density (Kg/dm3)	20-900℃	~1000℃	~1100℃	900℃	1000℃	1100℃	900℃	1000℃	1100℃
Value	7.8	17.68	18.0	19.15	129	116	103	20.4	22.3	23.8

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Microstructure

NH1949 is a cast nickel based alloy containing chromium, iron, aluminum, tungsten, and other trace alloying elements. Its microstructure is composed of carbide precipitates and austenite matrix, which has good structural stability. The presence of carbon and chromium leads to the formation of chromium rich carbides. The high-temperature strength of the alloy is significantly improved by hindering dislocation movement through the precipitation of carbides and the solid solution strengthening effect of tungsten.

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Anti carburization performance

NH1949 alloy has excellent anti carburizing performance. After carburizing in a mixed atmosphere of C2H2/H2 at 1100 ° C for 8 hours, the carburizing weight increase of NH1949 alloy is 1/10 lower than that of NH25-35Mic or NH35-45Mic alloys.

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Typical Mechanical Property at High Temperatures

Temperature (℃)	Ultimate Strength (MPa)	Yield strength (MPa)	Elongation (5d,%)
800	565	394	6.5
900	204	169	26.5
1000	124	62	30
1100	81	41	44.5

Temperature (℃)	Ultimate Strength (MPa)	Yield strength (MPa)	Elongation (5d,%)
800	565	394	6.5
900	204	169	26.5
1000	124	62	30
1100	81	41	44.5

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6Stress Rupture Strength Table

Temperature (℃)	1000hours Rupture Stress		10000hours Rupture Stress		100000hours Rupture Stress
Temperature (℃)	Average (MPa)	Minimum (MPa)	Average (MPa)	Minimum (MPa)	Average (MPa)	Minimum (MPa)
900	43.5	44.2	31.4	30.8	22.6	21.3
950	43.7	44.5	22.4	21.1	15.9	14.4
1000	31.7	31.0	16.0	14.5	11.2	9.7
1050	22.9	21.6	11.4	9.9	7.9	6.6
1100	16.6	15.1	8.2	6.8	5.5	4.4

Temperature (℃)	1000hours Rupture Stress		10000hours Rupture Stress		100000hours Rupture Stress
Temperature (℃)	Average (MPa)	Minimum (MPa)	Average (MPa)	Minimum (MPa)	Average (MPa)	Minimum (MPa)
900	43.5	44.2	31.4	30.8	22.6	21.3
950	43.7	44.5	22.4	21.1	15.9	14.4
1000	31.7	31.0	16.0	14.5	11.2	9.7
1050	22.9	21.6	11.4	9.9	7.9	6.6
1100	16.6	15.1	8.2	6.8	5.5	4.4

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Antioxidant performance

The NH1949 alloy has a low rate of weight gain during oxidation and a small amount of peeling. It can still maintain a protective AI203 oxide film of over 90% until 1200 ° C. The oxide film is evenly distributed and continuous, with a dense structure and a tight interface with the substrate, ensuring excellent anti coking performance of the alloy below 1200 ° C.
The NH1949 alloy has a low rate of weight gain during oxidation and a small amount of peeling. It can still maintain a protective AI203 oxide film of over 90% until 1200 ° C. The oxide film is evenly distributed and continuous, with a dense structure and a tight interface with the substrate, ensuring excellent anti coking performance of the alloy below 1200 ° C.

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Persistent fracture strength

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Coking mechanism of ethylene cracking furnace tubes

In the initial stage of cracking, catalytic coking is mainly used

Catalytic coking is a phenomenon caused by the deep catalytic deoxidation of transition metal elements such as Fe, Cr, Ni on the surface of furnace tubes through free radical like reactions.

Catalytic coking process

Hydrocarbon free radicals are adsorbed and deposited on metal surfaces with catalytic activity such as Fe, Cr, Ni, etc

Transition state carbides formed by the reaction between hydrocarbon radicals and metal particles

Transition state carbides are highly unstable at high temperatures and can decompose into carbon atoms and metal particles

The mechanism of anti coking

Forming an AI203 film with better high-temperature stability on the inner wall of the furnace tube, replacing the traditional Cr2O3 oxide film of heat-resistant steel.

◆ Good thermal stability: does not produce volatile components with increasing temperature, and can still maintain a stable structure at 1200C
◆ Not easy to break: The grain size is small, the thickness of the oxide layer is thin, and it is not easy to break or peel off
◆ Automatic repair: The oxide film can be automatically repaired during service, providing permanent protection
◆ Long cleaning cycle: the cleaning cycle is extended by 2-5 times

Advantages of New Materials

NH1949 High Temperature Alloy Performance Innovation

It is the first 1250℃ fully oxidation resistant and anti coking high-temperature alloy material in China, applied in ethylene cracking furnace tubes, metallurgical direct reduction iron DRI conversion tubes, environmental protection industries, etc;
Breaking through the global challenge of anti coking in cracking furnace tubes in the petrochemical industry, the comprehensive performance has reached the international leading level;
Every year, it can bring economic benefits of over 30 billion yuan to the domestic ethylene industry, and reduce emissions by more than 6 million tons of standard coal;

NH1949 Application and Intellectual Property Layout

The NH1949 high-temperature alloy furnace tube was first applied on a 150000 ton single furnace in the million ton ethylene unit of Dushanzi Petrochemical Company in October 2020, and two additional furnaces were added in 2021. In 2022, one new material product was signed with Liaoyang Petrochemical and one new material product was signed with Lanzhou Petrochemical. In 2023, Wanhua signed two new material products for furnaces, and Blrwelco in the United States signed one experimental furnace.

NPA Added Value

Qingdao NPA - a global innovation leader in the high-temperature alloy industry

Qingdao NPA can provide you with cracking furnace tube bank devices, conversion furnace tube bank devices, superheated steam furnace devices, DRI devices, and various matching static castings. We will combine Qingdao NPA's unique professional knowledge, quality control, and reaction speed to timely and accurately deliver to achieve supply guarantee effect. Qingdao NPA's supply guarantee ability is in an international leading position.

Qingdao NPA provides a full range of centrifugal casting and static casting parts, including various models of castings such as pipe sections, return bends, elbows, lifting ears, Y-shaped parts, T-shaped parts, tees, and brackets, as well as 800+sets of various wooden and metal molds. The factory follows the lean management concept, and through IE analysis, the overall planning is designed according to single piece flow. During the production process, PLC control and argon protection are used. The unique foundation and cylindrical design of the independently owned horizontal centrifuge makes the pipe sections more dense. The furnace tube is pulled out from the pouring end and the tail end to ensure structural consistency. The inner hole processing uses a professional pulling and boring machine with independent property rights to ensure the consistency of the furnace tube wall thickness.

In addition to our high alloy system used in the production process, its huge added value also makes Qingdao NPA stand out in the fiercely competitive environment. Because we understand your problem, we can increase your sales revenue and profit by tailoring and optimizing our products and services.

Services from Qingdao NPA

NPA provides recommendations for the entire lifecycle of high alloy components in your furnace. From design, manufacturing, delivery and installation, to operation and maintenance throughout the entire lifecycle, Qingdao NPA looks forward to becoming your partner, helping you reduce product costs, reduce energy, improve yield and product lifespan, and reduce air pollution.

Transfer of Proprietary Technology

Our experts and consultants have extensive experience in the petrochemical industry, understand the interactions between materials and processes, and can recommend the best applications and designs of our products. Provide reasonable suggestions based on your furnace condition and provide you with the best integrated solution.

Process Programmatization

Our mini program will monitor your product in real-time, and experts use computer-aided tools to analyze your historical operational data to identify trends and predict areas for improvement. A deep understanding of our product performance can ensure that the correct choices are made when evaluating maintenance and operational considerations.

Typical products

Patent and Intellectual Property Situation

We have completed the layout of intellectual property rights in 42 countries worldwide and have obtained patent authorizations for inventions in China, the European Union, Japan, Russia, Saudi Arabia, South Africa, South Korea, Singapore, Canada, India, and other countries.