APX4 is characterised by its very good resistance to corrosion in aggressive media coupled with very good mechanical and impact properties, is one of the martensitic grades, APX4 is comparable to APX4 acc. to SEW400 : 1991-02. showing sufficient corrosion resistance, good strength properties and high hardness with reduced carbon content, good corrosion resistance and cryogenic toughness up to -200 °C. The steel has high corrosion resistance especially to water.the steel has very good strength and corrosion resistance of welded joints, resistance to fatigue, very good parameters in low temperature environments, and corrosion resistance comparable to austenitic steels 18-8. In addition, it is characterized by good weldability.this material is a martensitic stainless steel for machine engineering, for pumps, fittings, compressors as well as for shipbuilding, The material supplied mainly in the form of bars is used for the production of valves, turbine subassemblies, nuts and bolts, shafts, pins, pistons, spindles, crankshafts, agitators in the chemical, energy, marine, shipbuilding, aviation/cryogenic industries.
Low-carbon stainless steel APX4 is a material very susceptible to heat treatment, which is used in many industries: marine, chemical, energy, shipbuilding, cryogenic.
Stainless steel APX4 is mainly used in the energy industry. It was from her are built all kinds of valves, turbine components, nuts, bolts, shafts, pins, Pistons, pins, spindles, crankshafts. Stainless steel is also used in APX4 aerospace, maritime, cryogenic. In addition, they are produced with the bolts, pump, tool holders.
This low-carbon stainless steel grade APX4 is one of the best martensitic steel grades, which is characterized by very high mechanical properties and resistance to corrosion. In addition, it has very good strength properties and a high degree of hardness with a low carbon content in the composition. High strength and corrosion resistance influence the ease of processing and make it a good welding material. The tensile strength of this steel grade ranges from 760 to 960 MPa, the yield strength is 550 MPa. The elongation is 14 % and the modulus of elasticity is E 200 GPa. In terms of physical properties of steel, it is worth remembering that the density is 7.70 g*cm3.
First of all, martensitic steel with low carbon content is many technological processes during metal forming and heat. The process of forging of stainless steel is possible at temperatures between 1150-900 ° C, roll forming starts at temperatures between 1150-900 ° C, annealing is best carried out at temperatures between 600-650 ° C, quenching of steel should be held from 950-1050 ° C, and tempering at temperatures between 550-620 ° C. In addition, the steel from this species is adapted to work in low concentrations and temperatures. Does not change its properties when working in moderately aggressive acids: acetic acid, citric acid, hydrochloric solution, pyrogal, tannin, stearic and compounds sulfur and nitrates. The individual needs of business grade of stainless 1.4418 is supplied in the form of rods, which then are used for the production of a variety of items.
| EN 10088-2: 2005 Stainless steels. Technical delivery conditions for sheet/plate and strip of corrosion resisting steels for general purposes |
| EN 10088-3: 2005 Stainless steels. Technical delivery conditions for semi-finished products, bars, rods, wire, sections and bright products of corrosion resisting steels for general purposes |
| EN 10028-7: 2007 Flat products made of steels for pressure purposes. Stainless steels |
| EN 10272: 2007 Stainless steel bars for pressure purposes |
| EN 10250-4: 2000 Open steel die forgings for general engineering purposes. Stainless steels |
| EN 10088-1: 2005 Stainless steels. List of stainless steels |
| EN 10088-5: 2009 Stainless steels. Technical delivery conditions for bars, rods, wire, sections and bright products of corrosion resisting steels for construction purposes |
| EN 10088-4: 2009 Stainless steels. Technical delivery conditions for sheet/plate and strip of corrosion resisting steels for construction purposes |
AOD+ESR
| Grades | Chemical Composition WT % | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| C | Mn | Si | P | S | Cr | Ni | Mo | N | |
| APX4 | Max 0.6 | Max 1.5 | Max 0.7 | Max 0.04 | Max 0.03 | 15.0 - 17.0 | 4.0 - 6.0 | 0.8 - 1.5 | Min 0.02 |
| Z6CND16-05-01 | Max 0.06 | Max 1.0 | Max 1.0 | Max 0.040 | Max 0.025 | 15.0 - 17.0 | 3.5 - 5.5 | 0.80 - 1.25 | - |
| Z8CND17-04 | 0.05 | 0.75 | - | - | - | 16.0 | 5.0 | 1.0 | 0.03 |
| S165M, SS 2387 | Max 0.05 | Max 1.5 | Max 1.0 | Max 0.045 | Max 0.030 | 15.0 - 17.0 | 4.0 - 6.0 | 0.8 - 1.5 | - |
| Properties | Temperature | |||||||
|---|---|---|---|---|---|---|---|---|
| 100℃ | 150℃ | 200℃ | 250℃ | 300℃ | 350℃ | 400℃ | ||
| p0,2 (MPa) | +QT760 | Min 520 | Min 510 | Min 500 | Min 490 | Min 480 | - | - |
| +QT900 | Min 660 | Min 640 | Min 620 | Min 600 | Min 580 | - | - | |
| +QT840 | Min 660 | Min 640 | Min 620 | Min 600 | Min 580 | - | - | |
| Modulus of elasticity, E (GPa) | 195 | - | 185 | - | 175 | - | 170 | |
| -1) | 10,3 | - | 10,8 | - | 11,2 | - | 11,6 | |
| Properties | Temperature | |||||||
|---|---|---|---|---|---|---|---|---|
| 100℃ | 150℃ | 200℃ | 250℃ | 300℃ | 350℃ | 400℃ | ||
| p0,2 (MPa) | +QT760 | Min 520 | Min 510 | Min 500 | Min 490 | Min 480 | - | - |
| +QT900 | Min 660 | Min 640 | Min 620 | Min 600 | Min 580 | - | - | |
| +QT840 | Min 660 | Min 640 | Min 620 | Min 600 | Min 580 | - | - | |
| Modulus of elasticity, E (GPa) | 195 | - | 185 | - | 175 | - | 170 | |
| -1 | 10,3 | - | 10,8 | - | 11,2 | - | 11,6 | |
density (kg/dm3) 7.70
electrical resistivity at 20 °C (Ω mm2/m) 0.70
magnetizability yes
thermal conductivity at 20 °C (W/m K) 15
specific heat capacity at 20 °C (J/kg K) 430
thermal expansion (K-1) :
Good weldability, X4CrNiMo16-5-1, 1.4418, Z8CND17-04 is readily weldable using all standard welding techniques. Care must however be taken to ensure that hydrogen or carbon containing gasses are not used when welding under shielded gas. Pre-heating of the work piece to a temperature between 100°C and 200°C is recommended. After welding, the weldment should either be annealed or tempered, as described before. If a filler material is required, then either a matching filler or Novonit® 4430 should be used.
The machinability of this grade of stainless steel is directly related to its hardness. X4CrNiMo16-5-1, 1.4418, Z8CND17-04 machines similar to carbon steels of the same hardness. Although it must be realised that the machining parameters will vary depending on the heat treated condition and hardness of the steel
Steel grade
Special steel