Tempering heat treatment
Tempering heat treatment
When we do mechanical parts processing, mold processing are often asked to do heat treatment or conditioning treatment, so exactly how a kind of modified treatment weeken the handle way? How common tempering hardness HRC after identification method?
Conditioning is a combination of high temperature quenching and tempering heat treatment method, mainly used to improve the comprehensive mechanical properties of materials; Hardness is a measure of hard and soft metal materials. HRC is one of the rockwell hardness scale, when the material hardness is more than HB (450 brinell hardness), you need to use the rockwell hardness meter to measure; According to the different loading force and pressure head can be measured in different scale: HRA, HRB, HRC; HRC is using 150 kg load and drilling coup-de-point forcer hardness is obtained.
So, on what is the difference between HB and HRC processing requirements?
The HRC modulation processing, quenching. The hardness of HRC and HB are two different testing methods, relative HB is more suitable for HRC hardness high hardness after quenching, and HB which is more suitable for annealing, heat treatment of materials. HRC is suitable for testing the hardness of HRC 20-67, the equivalent of HB225-650 low, measure, or no, this time with HB to measure accurately. Quenching in the HRC, on (+ high tempering after quenching) after get materials indicate the HB, so HB can be converted into a HRC to compare the material hardness after quenching, (because of the hardness of the material does not generally low ~ ~ this case with HRC than better, and make the corresponding heat treatment process is multi-purpose HRC) and then formulate relevant heat treatment process. On the material heat treatment method is quenched and tempered, tempering the material to meet its hardness HRC after ~ * * * *.
Ask what is the difference between HB and HRC conditioning treatment?
Brinell hardness (HB) : at a certain load (3000 kg) to a certain size (10 mm in diameter) of a hardened steel ball pressure into the material surface and stay for a period of time, to load, load with indentation area ratio, is the brinell hardness number (HB), the unit is kg force/was (N/was).
Rockwell hardness (HR) HRC: is a 150 kg load and drill coup-de-point forcer, finding the hardness for high hardness materials, such as hardened steel, etc.). For example, heat treatment of die steel reads HRC60 ~ 62, namely the rockwell hardness of 60-62. Rockwell hardness (Rockwellhardness), which is composed of rockwell (S.P.R ockwell) in 1921, is to use the rockwell hardness tester determination by the hardness value of the metal material. Should not have a unit value, use code "HR", said the measuring method is that, under the regulation of the loads, the steel ball or diamond indenter vertical pumped to the surface of the test material, produce dent, according to the indentation depth, load after using the formula of rockwell hardness HR = (K H)/C can calculate the rockwell hardness. Rockwell hardness number shown on the dial of hardness tester, can be read directly.
The above formula, K is constant, K = 0.2 MM diamond indenter, quenching steel ball head when K = 0.26 MM; H is given priority to load after after indentation depth of the specimens; C is for constant, usually C = 0.002 MM. Thus it can be seen that creasing the more shallow, HR value, the greater the material hardness is higher. Commonly used code HRA, HRB, HRC to represent the material hardness, the HRA said test load of 588.4 N (60 kg - F) using diamond cone apex Angle of 120 degrees of head pressure testing; Said HRB test load of 980.7 N (100 kg - F) quenching steel ball pressure test using 1.59 MM diameter; HRC said test load of 1471.1 N (150 kg - F) using the apex Angle of 120 degrees of diamond cone head pressure testing.
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