In industrial production, mould steel is the main body material of mould industry, function of the service life of the mould and the precision that make a part, quality, exterior, divide the design technology with the mould, production precision, and machine tool precision has outside Shanghaiguan with production operation, choosing mould material and correct ground correctly to implement heat treatment technology also is crucial. The main function index that the basis hardness that the heat treatment quality of the mould and performance characteristics regard judgement as with hardness normally is mould material and finished product mould. The condition getting power when the mould is working is complex, if heat up a mould,be to making the temperature field that change normally next bearing hand in change stress action, accordingly it should be had prevent a mould goodly to transform softer or the ability of plasticity condition, the appearance that and be below long-term work environment still maintains a pattern and dimension precision are changeless. The hardness of mould of general finished product, leng Zunmo provides constant choice to be in 59- 60HRC, heat makes a mould often choose to be controlled in 48HRC. Wearability also is the main function index of finished product mould. Surface of the metal when spare parts figuration and mould antrum produces opposite motion, wore away model antrum surface, to make the size shape of the mould, precision and exterior surface roughness happen change and invalidation. The wearability of the mould is by the heat treatment of the mould, especially exterior heat treatment decides, the main basis that evaluates mould wearability stand or fall also is hardness. The hardness test of mould steel basically is aimed at 3 kinds of circumstances, namely the hardness of mould steel material detects, of the semi-manufactured goods mould that passes heat treatment detect hardness, ask the exterior hardness after the mould surface heat treatment of tall wearability detects. Mould steel material basically is the armor plate that the course forgings, bloom or steel bar, offer money with anneal condition commonly. Steel of certain and plastic mould is returned with beforehand strong position (tone is handled character) for goods, the user can machine a mould directly and need not have follow-up heat treatment. Mould steel is planted by steel classification can divide steel of tool of the element that it is carbon, alloy tool steel and steel of high speed tool, chinese standard set to all sorts of mould steel leave factory hardness requirement, the requirement quenchs to the anneal hardness of rolled steel and sample hardness undertakes examining. Sclerometer of the family name in beautiful peaceful is applied extensively, its test is rapid, convenient, test value can be changed automatically into value of hardness of cloth family name, because this receives the application of certain level. The mould steel material that finished machining should undertake quenching temper is handled, repass essence is ground and polishing can become finished product pattern. It is more important that the mould hardness after quenching temper is handled detects, because at this moment material hardness is a very main quality index, it decided the service life of finished product mould greatly. Quench the mould of temper expects the requirement uses Rockwell hardness plan, test cost of HRC Rockwell hardness. Mould finished product needs to have join forces of first-rate put together to learn function, want to have enough hardness already, have certain tenacity even at the same time, and hardness and tenacity are a pair of contradiction, to be below the requirement that has reasonable tenacity, the mould has taller hardness, first-rate hardness value can is by limitation inside a narrower range, have 2-4 only normally HRC unit. The hardness test of mould of finished product, semi-manufactured goods is a problem that is hard to solve. All the time the solution with relatively good neither one. The mould with a few bulk and only lesser weight can move table Rockwell hardness plan on test. The hardness test that family name sclerometer is mould of finished product, semi-manufactured goods in offerred a solution, can check li of family name hardness of the mould first, next again conversion becomes HRC Rockwell hardness. Family name sclerometer is measured in is the hardness test method with mould industry most at present common application, and the field with the widest application of sclerometer of the family name in beautiful peaceful is mould industry. Be like in front be narrated, the hardness range with reasonable mould of finished product, semi-manufactured goods is narrower, family name sclerometer cannot satisfy such precision requirement in. But this is current the current situation of mould industry, without better settlement method. Handle to undertaking exterior cementite, nitriding or laser quench, the mould that case hardening handles needs to check the exterior hardness of the mould. Cementite layer normally thicker, be more than when cementite layer ply 0. When 8mm, can use Rockwell hardness directly plan, check HRC hardness. Be in when cementite layer ply 0.
6-0.
When 8mm, can use Rockwell hardness plan A staff guage. The trial power of A staff guage is lesser, have 60kg only (power of trial of C staff guage is 150kg) , a more shallow impress can be pressed in mould surface, unapt will sclerotic lamination is appeared, hardness test is more accurate. Measures HRA hardness value can pass the conversion that check a watch to become HRC hardness value conveniently. To thinner cementite layer or nitriding layer, want ply to be more than only 0.
1mm, can use exterior Rockwell hardness plan. Exterior Rockwell hardness plan trial power has 15kg, 30kg or 45kg only. Impress of exterior Rockwell hardness is smaller, for example, when mould hardness is 60HRC, value of exterior Rockwell hardness is 90.
6HR15N, impress deepness is equal to (100-90.
6) X0.
001mm=0.
009mm, such impress naked eye is hard to differentiate almost. Because of this surface Rockwell hardness plan still can check finished product mould, measures hardness value is OK also conversion is worth into HRC hardness. Hardness is the function with mould the mainest steel, wait for other property to take care of tenacity, the optimal limits of mould hardness is a narrower interval, accordingly, how can use beautiful peaceful in the spot portable sclerometer checks a mould accurately to hardness is made in the mould and use an unit to have very important sense. It can promote a mould the quality of the product, promote a mould production technical standard, prolong mould life. CNC Milling
CNC Machining