Stainless Alloy Steel Protos 90e Hauni Final Cut Blade

Protos 90e Of Hauni Final Cut Blade To Cut Cigarette Rod With Filters Assembled By Cigarette Making Line

Filter Knife is a component of cigarette making machines to slice filter rod after being connected to cigarette rod.

Invention

Robert Bunsen discovered chromium's resistance to strong acids. The corrosion resistance of iron-chromium alloys may have been first recognized in 1821 by Pierre Berthier, who noted their resistance against attack by some acids and suggested their use in cutlery.

In the early 1800s, James Stodart, Michael Faraday, and Robert Mallet observed the resistance of chromium-iron alloys ("chromium steels") to oxidizing agents.

The invention of stainless steel followed a series of scientific developments, starting in 1798 when chromium was first shown to the French Academy by Louis Vauquelin.

Ferritic Stainless Steels

Ferritic stainless steels possess a ferrite micro-structure like carbon steel, which is a body-centered cubic crystal structure, and contain between 10.6% and 27.2% chromium with very little or no nickel. They are magnetic.

This micro-structure is present at all temperatures due to the chromium addition, so they are not hardened by heat treatment. They cannot be strengthened by cold work to the same degree as austenitic stainless steels.

Heat Treatment Of Martensitic Stainless Steels

Austenitizing, where the steel is heated to a temperature in the range 980–1,050 °C (1,800–1,920 °F), depending on grade. The resulting austenite has a face-centered cubic crystal structure.

Tempering. Martensite would be heated to around 500 °C (932 °F), held at such high temperature, then air-cooled. Higher tempering temperatures decrease yield strength and ultimate tensile strength but increase the elongation and impact resistance.

Quenching. The austenite is transformed into martensite, a hard body-centered tetragonal crystal structure. The quenched martensite is too hard and brittle for most applications. Some residual austenite may remain.