18Ni, 20Ni and 25Ni 3 typical series, which series is the easiest to manufacture and the most widely

18Ni300 martensitic aging steel is an ultra-high-strength steel based on carbon-free or ultra-low-carbon fe-Ni martensitic and precipitated and hardened by intermetallic compounds after aging treatment. The strength of this type of steel does not come from carbon, but from the precipitation of intermetallic compounds.

<> performance characteristics. Shanghai Bingzheng Industrial 18Ni steel solid solution after the formation of ultra-low carbon martensite, hardness of 28 30HRC, after aging treatment, due to the dissolution and precipitation of various types of intermetallic compounds to obtain aging hardening, the hardness can rise to the steel The outstanding feature is that it still has good toughness and high fracture toughness under the conditions of ultra-high strength and high hardness. At the same time, this kind of steel has no cold work hardening, small aging heat treatment deformation, good welding performance, and the surface can also be nitrided.

Shanghai Bingzheng Industrial 18Ni martensitic aging steel has high strength and hardness (ultra-high tensile strength, surface hardness 50 54HRC), good toughness and plasticity, is a key material for the manufacture of aerospace and defense industry equipment, and has been widely used in aviation, aerospace, precision molds and other industrial fields, and is currently widely used at home and abroad as a material for manufacturing high-precision load-bearing parts such as rocket engine shells, missile shells, uranium isotope centrifugal separators, high-speed rotating drums, etc.

18ni (350) steel is a typical martensitic aging steel, is an aging hardening plastic mold steel, the steel has a low carbon content, and the alloy Ti, Al, Co, and Mo play a role in aging hardening. Impurities have a great influence on the properties of martensitic age-hardened steels, and have a more obvious effect on steels with higher yield strength. This requires the steel to be smelted in vacuum to reduce impurities, segregation and gas content in the ingots to ensure that the steel has good toughness and fatigue resistance.

The former contains a CR of 35 (mass percentage), the latter has a mass of 40, and the rest of the content is the same.

Alloy steel with high strength and good chemical stability at high temperatures. It includes two types of oxidation-resistant steels (or high-temperature non-peeling steels) and heat-strong steels. Oxidation-resistant steels generally require good chemical stability but are subjected to lower loads.

Thermally strong steels require high high-temperature strength and corresponding oxidation resistance. Heat-resistant steels are commonly used in the manufacture of boilers, steam turbines, power machinery, industrial furnaces, and parts that work at high temperatures in industrial sectors such as aviation and petrochemicals. In addition to high-temperature strength and resistance to high-temperature oxidation and corrosion, these parts also require sufficient toughness, good machinability and weldability, as well as certain structural stability according to different applications.

In addition, a number of new low-chromium-nickel oxidation resistant steel grades have been developed.

CR20Ni80 Nichrome Resistance alloy.

CR20NI80 Introduction:

80Ni-20Cr has high nickel and chromium content, low iron content, and has good oxidation resistance, thermal strength and low positive temperature coefficient below 1000. At room temperature, it has high plasticity, cold stamping and welding properties. The alloy is single-phase austenite after solution treatment, and the structure is stable during use.

The application range of CR20NI80 is as follows:

1.As a heating element, it is mainly used for periodic heat treatment furnaces with a temperature of less than 1000, such as carburizing furnaces, bell furnaces, ammonia decomposition furnaces, etc.

2.Heating wire for high-grade electric heating pipes and high-grade household electric heaters3For resistance bands in high-quality resistance boxes.

4.It can also be used as a high-quality heat-resistant steel structural part, such as high-temperature mesh belt, burner frame and other CR20Ni80 main specifications:

Wire, wire rod, flat strip, forming furnace strip, strip, forging rod, hot rolled rod, cold and hot plate, pipe, machined finished products.

CR20Ni80 is a resistive electric heating alloy, which has stable structure, stable electrical and physical properties, good mechanical properties at high temperature, good cold deformation plasticity, good weldability, and will not produce brittle fracture after long-term use. It is mostly used in the manufacture of household appliances and heating elements with a working temperature of less than 1000 meters, and has a long service life. ** higher due to high nickel content.

Implement the standard GB T1234-2012

The chemical composition is:

c ≤；mn ≤；

p ≤；s ≤；

si：；cr：；

ni: margin.

Fe AL components can be used up to 1200 °C

Fast life: not less than 80h

Melting point 1400

Density grams cubic centimeters.

Resistivity: Soft wire.

Nominal diameter< (20).

Nominal diameter< (20).

Nominal diameter< (20).

Flexible strips. Alloy strip thickness (20).

Alloy strip thickness (20).

Alloy strip thickness (20).

Specific heat capacity elongation 20

Tensile strength: not less than 650 rm mpa

Thermal conductivity: 15 W ( ( ( 20 )

Linear expansion coefficient 18

Microstructure austenite.

Grade: CR20Ni80 (nickel-chromium wire).

CR20Ni80 alloy has excellent comprehensive properties and is the preferred variety for making high-quality electric heating elements. It has a series of advantages such as good oxidation resistance, high strength, non-magnetism, high emissivity, good corrosion resistance, and no softening. When used for long periods of time, it does not deform and has little permanent elongation.

Perennial stock round bar, plate, seamless pipe, tape and reel!

Main chemical composition c; mn ≤；p ≤；s ≤；si：；cr：；Fe ni: Margin.

There is no such thing as this material spot, so you can only find one that is close.

Incoloy 800H Features:

1.Excellent corrosion resistance in very high temperatures up to 500 °C in aqueous media.

2.Very good resistance to stress corrosion.

3.Very good processability.

Incoloy 800H Metallographic Structure:

Incoloy 800h is a face-centered cubic lattice structure. The extremely low carbon content and improved Ti:C ratio increase structural stability and resistance to sensitization and intergranular corrosion. Low temperature annealing at around 950 guarantees a fine-grained structure.

Incoloy 800H Corrosion Resistance:

Incoloy 800H is resistant to a wide range of corrosive media. Its high nickel content gives it excellent resistance to stress corrosion cracking in aqueous corrosion conditions. The high chromium content results in better resistance to pitting corrosion and crevice corrosion cracking.

The alloy has good corrosion resistance to nitric acid and organic acids, but has limited corrosion resistance in sulfuric acid and hydrochloric acid. In addition to the possibility of pitting corrosion in halides, there is good corrosion resistance in both oxidizing and non-oxidizing salts. It also has very good corrosion resistance in water, vapor and mixtures of steam, air and carbon dioxide.

Incoloy 800h hot working.

1. The temperature range is 1200 950, and the cooling method is water quenching or rapid air cooling.

2. In order to obtain the best performance and creep resistance, solution treatment should be carried out after hot processing.

3. The material can be directly fed into the furnace that has been heated to 1200 °C, and it will be quickly released after holding for enough time, and the hot processing will be carried out within the specified temperature range. When the temperature of the material drops below the hot working temperature, it needs to be reheated.

Incoloy 800H cold worked.

1. The work hardening rate is greater than that of austenitic stainless steel, so it is necessary to select the processing equipment. The cold-worked material should be in a solution heat-treated state, and intermediate annealing should be carried out when the amount of cold working is large.

2. If the amount of cold working is greater than 10%, the workpiece needs to be treated with a second solid solution.

Incoloy 800H welding process.

It is suitable for welding with the same material or other metals by any traditional welding process, such as tungsten electrode inert gas shielded welding, plasma arc welding, manual sub-arc welding, metal pole inert gas shielded welding, and melting pole inert gas shielded welding, of which pulse arc welding is the best solution. If manual arc welding is used, it is recommended to use (AR+HE+H2+CO2) as the shielding gas.

Incoloy 800H range of applications:

1.Nitric acid condenser – resistant to nitric acid corrosion.

2.Steam heating tubes – very good mechanical properties.

3.Heating element tubes – very good mechanical properties.

The alloy typically contains 15-25% CR and 30-45% nickel, with small amounts of aluminum and titanium.

Characteristics and uses of 18Ni martensitic aging steel:

The representative steel grades of 18Ni steel are 00Ni18CO8Mo3Tial[18Ni(200)]022Ni18CO8Mo3Tial, 00Ni18CO8Mo5Tial[18Ni(250)]022Ni18CO8Mo5Tial, 00Ni18CO9Mo5Tial[18Ni(300)]022Ni18CO9Mo5Tial, and 00Ni18CO13Mo4Tial[18ni(350)] 022ni18CO13mo4tial steel.

18Ni steel is a typical martensitic aging steel, the carbon content in the steel is low, the alloying elements that play a role in the aging hardening are Ti, Al, Co, Mo, impurities have a great impact on the performance of martensitic aging hardening steel, and the effect on the steel with higher yield strength is more obvious. This requires this kind of steel to be smelted by vacuum to reduce impurities, segregation and gas content in the ingot, so as to ensure that the steel has good toughness and fatigue resistance.

In 18Ni steel, carbon has a great influence on the strength of the steel, and even a very small amount of carbon can make the martensitic strength significantly higher. However, after increasing the mass fraction of carbon, it will reduce the yield strength of the steel, so the mass fraction of carbon in 18Ni martensitic aging steel should not be exceeded.

The S in 18Ni steel are harmful. S exists in the steel as sulfides and is distributed in the direction of hot rolling, resulting in the anisotropy of the steel, so it is required to reduce the sulfur content of the steel as much as possible.

A large amount of Ni is added to 18Ni steel, and the main function is to ensure that a single martensite can be obtained after the solid solution is quenched, and secondly, the effect of Ni on Mo is to form the aging strengthening phase Ni3Mo. When the mass fraction of NI exceeds 10%, it can also improve the fracture toughness of martensitic aging steel.

After the solution of 18Ni steel is formed, ultra-low carbon martensitic is formed, and the hardness is 28 30HRC; After aging treatment, the hardness can rise to 50HRC due to the dissolution and precipitation of various types of intermetallic compounds. This type of steel still has good toughness and high fracture toughness under the condition of high strength and high toughness. At the same time, this kind of steel has no cold work hardening, small aging heat treatment deformation, good weldability, and the surface can also be nitrided.

18Ni low-carbon martensitic aging steel is mainly used to manufacture high-precision, super-mirror, complex cavities, large cross-sections, mass production of mechanical parts and plastic molds, but due to its high cost, the use is limited.

00Ni18CO8Mo5TIAL is a martensitic aging steel, C250 022Ni18CO8Mo5Tial 18Ni(250) GR72 18NI1700 martensitic aging steel.

Nominal chemical component.

c≤ni17-19

p≤s≤si≤mn≤

Mechanical performance.

Solution temperature 815-830

Aging temperature 480 5

Hardness HRC50-52 after aging

Tensile strength 1850

Yield strength 1800

Elongation after fracture 10-12

The section shrinkage is 48-58

Typical high-alloy martensitic age-hardening steels include 18Ni (200) (00Ni18CO8Mo3Tial) steel, 18Ni (250) (00Ni18CO8Mo5Tial) steel, 18Ni (300) (00Ni18CO9Mo5Tial) steel, 18Ni (350) (00Ni18CO13Mo4Tial) steel, etc., which form ultra-low carbon martensitic after solid solution, with a hardness of about 30 32HRC; After aging treatment, due to the removal and precipitation of various types of intermetallic compounds, the aging hardening is obtained, and the hardness can rise to more than 50HRC. This type of steel still has good plasticity, toughness and high fracture toughness under the conditions of high strength and high toughness.

00Cr20Ni18Mo6Cu, reads: zero zero chromium, twenty nickel, eighteen-molybdenum, six-copper. It is an austenitic stainless steel grade.

It is twice as strong as 300 series stainless steel, with excellent impact toughness and resistance to pitting, crevice corrosion and chlorinated corrosion cracks. It has a good value for money.

There are no 00cr20ni18mo6cun (zero zero chromium, eiconickel, eighteenmolybdenum, hexacopper nitrogen) metal grades.