1, 440A-440B-440C, carbon content and hardness by 2113A-B-C gradually increase (5261A-0.75%-B0.9%-C1.2%). 2, 440A Advantages: is better rust resistance, suitable for 4102 used to make diving 1653 knife class, hardness due to the impact of carbon content, hardness of about 56 or so, the production of daily knife can only be said to be just right. Disadvantage: low hardness. 3, 440C Advantages: the hardness is better than 440A, due to the carbon content of 1% - 1.2%, so that the hardness of 440C 58 ~ 60 or so, it is a more desirable material for making knives. Such as from the performance of the knife and rust effect comparison, the closest 440C steel is ATS-34, ATS-34 heat treatment of the hardness of the basic can reach 60. Disadvantages: rust resistance is lower than 440A, /qa/2020/06/28/19/ 1593344635253616
Expanded Information:
The principle of tool machining Rolling cutter can make use of the plastic deformation of metal at room temperature, so that the surface of the workpiece surface of the microscopic unevenness of the rolling so as to achieve the purpose of changing the surface structure, mechanical properties, shape and size. Therefore, this method can simultaneously achieve the finishing process and strengthen the two purposes, is grinding, turning can not be done. Regardless of what kind of metalworking tool processing, the surface of the parts will always leave a fine uneven cutter marks, staggered peaks and valleys phenomenon, a certain amount of pressure, so that the surface metal of the workpiece to produce a plastic flow, fill in the original residual low-concave valley, and to achieve a reduction in the surface roughness of the workpiece value. Due to the plastic deformation of the rolled surface metal, the surface organization of cold hardening and grain thinning, the formation of dense fibrous, and the formation of residual stress layer, hardness and strength, thus improving the surface of the workpiece wear resistance, corrosion resistance and compatibility. Rolling is a plastic processing method without cutting. Inner conical rolling cutter Rolling tool has no cutting edge, processing technology is safe, convenient, basically can be applied in all metal processing industry, can accurately control the accuracy, several advantages: Outer conical rolling cutter 1, improve the surface roughness, roughness can basically reach Ra ≤ 0.08_m or so. 2, correct the roundness, ellipticity can be ≤ 0.01mm. 3, improve the surface hardness, so that the deformation of the force is eliminated, the hardness to increase the HV ≥ 4 ° 4, the processing of the residual stress layer, to improve the fatigue strength increased by 30%. 5, improve the quality of fit, reduce wear and prolong the service life of the parts, but the processing cost of the parts instead of reducing. Application advantages of high efficiency - a few seconds to the surface can be processed to the required surface accuracy, the efficiency is 5-20 times the grinding, turning 10-50 times more. Through-hole type rolling cutter High quality - a feed to achieve Ra0.05-0.1um mirror precision; and make the surface to get extrusion hardening, wear resistance, fatigue strength increased; eliminated the surface of the force plastic deformation, dimensional accuracy can be relatively long-term stability. Blind hole type rolling cutter Economy - no need for large-scale equipment, such as capital, land occupation, power consumption, waste treatment and other inputs; no need for professional mechanic input. Convenient - can be clamped on any rotary and feeding equipment, without professional training can be processed with mirror precision. Environmental protection - no chips (protect the environment), low energy consumption. Safety - Cutting-free rolling tools have no cutting edge. Rolling head is divided into ordinary lathe special rolling head and deep hole drilling and boring machine special deep hole rolling head, the above is the ordinary lathe special rolling head, which is deep hole drilling and boring machine special rolling head Baidu Encyclopedia - Stainless Steel Baidu Encyclopedia - 440A