Stainless steel grade 314 has excellent high-temperature resistance characteristics among the chromium-nickel steels series. The silicon content in this material improves oxidation and carburization resistance; however, it can become very brittle when subjected to prolonged temperatures of 649-816°C (1200- 1500°F). Type 314 stainless steel is effectively a 310 type stainless with a higher level of silicon, for increased high-temperature oxidation resistance.
Stainless steel grade 314 can be heat treated by annealing the material at 1038-1149°C (1900-2100°F), and then quenching in water or rapidly air cooling. Grade 314 steel can be hardened only through cold working. To perform machinability of grade 314, coolant and high-speed turning tools are recommended. After slowly heating the material to 871°C (1600°F), it should be thoroughly soaked, and then followed by quickly heating to 1093 -1232°C (2000-2250°F) , to perform forging, flanging, or working.
This grade is used in applications that take advantage of its excellent high-temperature scaling resistance and creep strength. It is widely used for furnace parts.
This grade may be forged between 2100/1800ºF (1150/980ºC.) Small parts should be rapidly air cooled or water quenched after forging. For optimum corrosion resistance, parts should be annealed after forging.
Parts should be annealed at 1920/2100ºF (1050/1150ºC) and water quenched.
Type 314 machines in a similar manner to other 18/8 types, giving tough, stringy chips. Maximum feeds and slow speeds will give best machinability. A small amount of cold work on bars will improve the surface finish after machining.
Type 314 can be welded by shielded fusion and resistance methods, but oxyacetylene welding should be avoided to prevent carbon pick up in the welds. There is little risk of cracking in the welds. Should filler metal be required, 310 rods are recommended. A post weld anneal will prevent the occurrence of intergranular corrosion.