440A
Advantages: good rust resistance, suitable for making diving knives. Due to the influence of carbon content, the hardness is about 56, so it can only be said that it is just right to make a daily knife.
Disadvantages: low hardness.
340 degrees celsius
Advantages: hardness is better than 440A. Because the carbon content is 1%- 1.2%, the hardness of 440C is about 58~60, so it is an ideal material for making tools. For example, from the comparison of performance and antirust effect after cutting, the steel closest to 440C is ATS-34, and the hardness of ATS-34 after heat treatment can basically reach 60.
Disadvantages: rust resistance is lower than 440A,
Extended data:
Tool machining principle
Rolling cutting tool can flatten the micro-roughness of workpiece surface by using the plastic deformation of metal at room temperature, thus changing the surface structure, mechanical properties, shape and size. So this method can achieve the purpose of finishing and strengthening at the same time, which can not be achieved by grinding and turning.
No matter what kind of metal processing tools are used for processing, there will always be tiny uneven marks on the surface of the parts, and there will be staggered peaks and valleys. Under a certain pressure, the metal on the surface of the workpiece will flow plastically, filling the original residual valleys, thus reducing the roughness of the workpiece surface.
Due to the plastic deformation of the rolled surface metal, the surface structure is cold hardened, the grains are refined, a dense fibrous structure is formed, and a residual stress layer is formed, which improves the hardness and strength, thus improving the wear resistance, corrosion resistance and adhesion of the workpiece surface. Rolling is a plastic processing method without cutting.
Inner tapered roller cutter
The hobbing cutter has no blade, and the processing technology is safe and convenient. It can be basically applied to all metal processing industries, and the precision can be accurately controlled. It has several advantages:
External tapered roller cutter
1, improve the surface roughness, and the roughness can basically reach Ra≤0.08 &；; Microscopic; About m.
2. The roundness is correct, and the ellipticity can be ≤ 0.01mm..
3, improve the surface hardness, eliminate stress and deformation, and improve the hardness by HV ≥ 4.
4. Residual stress layer exists after machining, and the fatigue strength is improved by 30%.
5, improve the quality of cooperation, reduce wear and prolong the service life of parts, but reduce the processing cost of parts. The application advantage is high efficiency-the surface can be machined to the required surface accuracy in a few seconds, and the efficiency is 5-20 times that of grinding and 10-50 times that of turning.
Through-hole rolling cutter
High-quality mirror accuracy of Ra0.05-0. 1um can be achieved by one feed; Surface extrusion hardening improves wear resistance and fatigue strength; The plastic deformation of the surface is eliminated, and the dimensional accuracy can remain stable for a relatively long time.
Blind hole rolling cutter
Economy-large equipment does not need capital, land occupation, power consumption, waste residue treatment and other inputs; Without the input of professional and technical personnel. Convenient-it can be clamped on any rotating and feeding equipment, and the mirror surface accuracy can be machined without professional training. Environmental protection-no chip (environmental protection) and low energy consumption.
Non-safety cutting hob has no blade. The rolling heads are divided into special rolling heads for common lathes and deep-hole rolling heads for deep-hole drilling and boring machines. The above is the special rolling head for ordinary lathe, and it is the special rolling head for deep hole drilling and boring machine.
Baidu encyclopedia-stainless steel
Baidu encyclopedia -440A