Of hardness of workpiece of exterior heat treatment detect the method is summari
From;    Author:Stand originally
Cent is exterior heat treatment two kinds big, one kind is thermo-chemical treatment, one kind is the surface quenchs temper heat treatment, law of proved recipe of its hardness check is as follows:

1, thermo-chemical treatment

Thermo-chemical treatment is to make workpiece surface infiltration one plant or the atom of a few kinds of chemical elements, change the chemical composition of workpiece surface, organization and property thereby. Mix via quenching after microtherm temper, workpiece surface has tall hardness, wearability and osculatory exhaustion strength, and the core ministry of workpiece has tall obdurability again.

The main technique parameter of thermo-chemical treatment workpiece is sclerotic layer deepness and exterior hardness. Sclerotic layer deepness still should use diamond pyramid hardness plan will detect. Detect fall to hardness from workpiece surface 50HRC the distance that. The exterior hardness that this is workpiece of thermo-chemical treatment of effective and sclerotic deepness detects with exterior temper by dipping in water the hardness of workpiece of igneous heat treatment detects close, can use diamond pyramid hardness plan, exterior Rockwell hardness plan or Rockwell hardness plan will detect, it is nitriding only thick ply is thinner, do not be more than 0.7mm commonly, cannot use Rockwell hardness again at this moment plan.

2, the surface quenchs temper heat treatment

The surface quenchs temper heat treatment uses the means that the induction heats or blaze heats to undertake normally. Main technique parameter is exterior hardness, local hardness and deepness of effective and sclerotic layer. Hardness detects can use diamond pyramid hardness plan, also can use Rockwell or exterior Rockwell hardness plan. Trial power (rear sight) choice and deepness of effective and sclerotic layer and workpiece surface hardness are concerned. Here involves 3 kinds of sclerometer.

Diamond pyramid hardness plan the important step that is hardness of surface of workpiece of test heat treatment, it can choose the trial power of 0.5 ~ 100kg, the test is thin to the case hardening layer with thick &nbsp0.05mm, its precision is highest, distinguishable the little difference that gives hardness of surface of heat treatment workpiece. Additional, deepness of effective and sclerotic layer also wants by diamond pyramid hardness plan will detect, so, be machined to having exterior heat treatment or use the unit of workpiece of exterior heat treatment in great quantities, deploy a diamond pyramid hardness plan be necessary.

Exterior Rockwell hardness plan also be very comfortable quench at checking the surface of workpiece hardness, exterior Rockwell hardness plan 3 kinds of staff guage can choose. Can check effective and sclerotic deepness to exceed all sorts of case hardening workpiece of 0.1mm. Although exterior Rockwell hardness plan precision does not have diamond pyramid hardness plan tall, but manage what check with qualification to detect as quality of heat treatment factory method, can have satisfied a requirement. It still has besides the operation is simple, use convenient, price inferior, measure rapid, can read directly take the characteristic such as hardness value, use exterior Rockwell hardness plan can be opposite group by group workpiece of exterior heat treatment undertakes fast nondestructive chase detect. This have important sense to metallic treatment and mechanical production factory.
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