1.4057

1.4057 is a kind of martensitic stainless steel with a good combination of strength and toughness. It is a low-carbon chromium-nickel corrosion-resistant steel with high strength and hardness. It has good corrosion resistance to oxidizing acids (a certain temperature, concentration of nitric acid, most organic acids), and organic acid aqueous solutions. Sub-temperature quenching can effectively inhibit the high temperature temper brittleness of the steel. It can reduce the brittle transition temperature of steel, improve toughness, change the fracture morphology from quasi-cleavage type to dimple type, and increase the enrichment of alloying elements into the matrix and δ-ferrite, which improves the toughness of steel. At the same time still maintain a high intensity level. However, the welding performance of this steel is not good, and it is easy to produce cracks. Therefore, welding is not suitable when manufacturing tools. [1]
1.4057 Chemical composition:
carbon C: ≤0.12-0.22
silicon Si: ≤1.00
manganese Mn: ≤1.50
sulfur S: ≤0.015
phosphorus P: ≤0.040
chromium Cr: 15.00-17.00
nickel Ni: 1.5-2.5
1.4057 hardness: annealing ,≤285HB
1.4057 heat treatment specification and metallographic structure
1.4057 heat treatment specification: 1) Annealing, 680～700℃ high temperature tempering air cooling; 2) Quenching, 950～1050℃ oil cooling; 3) Tempering 275～350℃ air cooling.
1.4057 Metallographic structure: The structure is characterized by martensite.
1.4057 Delivery status: Generally delivered in heat-treated condition, and the type of heat treatment is indicated in the contract; if it is not indicated, it will be delivered in non-heat-treated condition.
1.4057 Physical properties:
1) Critical point temperature (approximate value): Ac1=810°C, Ar1=780°C, Ms=357°C.
2) Density: 7.75g/cm3
3) Mass heat capacity at constant pressure: 459.8J/ (kg·K).
4) Elastic modulus (20°C): 210000MPa.
5) Resistivity: 0.70×10-6Ω·m
6) Linear expansion coefficient: Temperature 20-100°C/20~200°C/20~300°C/20~400°C/20~500°C, line Expansion coefficient: 10.0×10-6K-1/10.0×10-6K-1/11.0×10-6K-1/11.0×10-6K-1/11.0×10-6K-1.
7) Thermal conductivity: temperature 20°C/100°C/200°C/300°C /400°C/500°C/600°C/700°C/800°C /900°C, thermal conductivity 20.9[w/(m·K)]/21.7[w/(m·K)]/22.6[w/(m·K)]/23.4[w/(m·K)]/24.2[w/(m ·K)]/25.1[w/(m·K)]/25.9[w/(m·K)]/26.7[w/(m·K)]/28.0[w/(m·K)]/29.7 [w/(m·K)]. [2]
1.4057 Material delivery status:
1. Bars are supplied in forged, black-skinned, polished or polished state;
2. Cakes and ring blanks are supplied in forged state;
3. Rings are supplied in solid solution State supply;
4. Sheets are supplied after solid solution, alkali pickling, straightening and trimming; strips are delivered after cold rolling, solid solution, and descaling; wire is in solid solution pickled disc or straight strip, The solid solution straight bar is delivered in a finely polished state. Plate and strip surface: bright surface, 2B surface, BA (6k) mirror surface, 8K mirror surface, brushed surface, frosted surface Fine plate surface: bright surface, matte surface, matte surface, mirror surface, and other light colors can be plated according to customer requirements .
1.4057 Defects
during processing : We should pay attention to the following points during processing
(1) Dust and floating iron powder are embedded on the surface of the material
(2) Corrosion and deposits can occur on rough grinding and rough surfaces,
(3) Welders When the arc is started on the surface of the sheet, the protective film is damaged
(4) Grease paint pen printing residual adhesive.
1.4057 Main application: Generally suitable for the manufacture of nitric acid, acetic acid production and light industry, textile and other industries that require both toughness and corrosion resistance of shafts, piston rods, pumps and other parts.