What is the difference between 1.4306 and 1.4307?

1.4306 and 1.4307 are two common stainless steel material numbers, with some differences in chemical composition, performance and application scenarios:

1.4306 is the German number for 304L stainless steel, which is an ultra-low carbon austenitic stainless steel. The chromium content of 1.4306 chemical composition is usually 18% - 20%, and the nickel content is 8% - 12%. The low carbon content effectively reduces the precipitation of chromium carbide and reduces the risk of intergranular corrosion.

1.4307 stainless steel corresponds to the Chinese grade 1Cr18Ni9, which is an 18-8 type austenitic stainless steel with a higher carbon content than 1.4306, about 0.15%, a chromium content of 17.00 - 19.00%, and a nickel content of 8.00 - 10.00%.

In terms of corrosion resistance, 1.4306 stainless steel pipes have low carbon content. During hot processing such as welding, it is not easy to cause chromium depletion at the grain boundary due to the precipitation of chromium carbide. It has excellent intergranular corrosion resistance and performs well in environments such as industrial wastewater containing acidic and alkaline substances and humid marine atmosphere.

1.4307 stainless steel seamless pipes have good corrosion resistance, but the risk of chromium depletion at the grain boundary during hot processing is relatively high, and the intergranular corrosion resistance is relatively poor. 1.4306 stainless steel has a good balance of strength and toughness and can withstand certain pressure, tension and impact. 1.4307 stainless steel has slightly higher strength but slightly lower toughness, and is more advantageous in the use of some simple structural parts with high strength requirements.

1.4306 stainless steel cold-drawn tubes are often used in food processing equipment with extremely high requirements for corrosion resistance and safety to ensure that food is not contaminated; reactors and pipelines in the pharmaceutical industry to ensure the quality of drugs; and in the field of medical equipment to meet biocompatibility requirements.
1.4307 stainless steel welded pipes are often used in the field of architectural decoration, such as making railings and handrails to meet aesthetic and certain strength requirements; some non-critical structural parts in ordinary industrial equipment to achieve a balance between cost and performance.