FAQs

Quelle est la période de garantie pendant laquelle les produits chinois sont exportés vers les marchés internationaux?


Answer: in China, we supply 12-month as warranty time for the customers, the date time is started to count from the machine installed and acceptance checked. As for instruments exported to international market, it is 15-month for warranty time, but it is started to count from the shipping time, the shipping time will be declared and found on the bill of loading or airways.


Question 2.Qui a inventé le procédé d 'essai de Lord?


Answer: It is acceptable that Mr. Hugh M. Rockwell (1890–1957) and Mr. Stanley P. Rockwell (1886–1940) from Connecticut in the United States co-invented the "Rockwell hardness tester," a differential-depth machine. They applied for a patent on July 15, 1914.[4] The requirement for this tester was to quickly determine the effects of heat treatment on steel bearing races. The application was subsequently approved on February 11, 1919, and holds U.S. Patent 1,294,171.


Question 3.Qu'est - ce qui distingue roxwell et lowright?


A fundamental distinction is made between two types of Rockwell method: Regular Rockwell (or Rockwell) and Superficial Rockwell (or Super Rockwell):


1. Rockwell: The perforce (or p reload) is always 10 kgf, while the total test force (also referred to as main force or load) can vary between 60, 100, or 150 kgf.
2. Super Rockwell: The perforce is 3 Kgf, while the main force can vary between 15, 30, or 45 Kgf.


Méthode d 'essai Rockwell Super Rockwell
Précontrainte 10 kg 10 kg 10 kg 3 000 pieds cubes. 3 000 pieds cubes. 3 000 pieds cubes.
Force majeure 150 kilogrammes. 100 kilogrammes. 60 kilogrammes. 45 kg de force. 30 kilogrammes. 15 kilogrammes de force



La valeur de dureté de l 'hyperlow peut être convertie en valeur de dureté de Low et inversement.La méthode de Lord en surface a été inventée aux États - Unis, où son utilisation est beaucoup plus courante qu 'en Europe.Il est particulièrement utile pour tester la dureté d 'un composant mince et d' une couche mince, ou pour calculer un échantillon dont la dureté dépasse une règle de Lord classique.


Rockwell and Superficial hardness testing shall be performed in accordance with the latest revision of ASTM E18.

There are two general classifications of the Rockwell test: the Rockwell hardness and the Rockwell superficial hardness test. In the Rockwell hardness test the preliminary test force is 10 kgf. Total test forces are 60 kgf, 100 kgf and 150 kgf. In the Rockwell superficial hardness test, the preliminary test force is 3 kgf and total test forces are 15 kgf, 30 kgf, 45 kgf. The indenter of either test shall be of spheroconical or spherical configuration The standard indenters are the diamond spheroconical and tungsten carbide ball indenters' 1/16, 1/8, 1/4, 1/2 inch in diameter. Annex 3 or A3. STANDARDIZATION OF ROCKWELL INDENTERS, covers the requirements of indenters to be used. The dust, dirt, grease and scale shall not be allowed to accumulate on the indenter as this will affect the test. Anvils used for indention’s must be suitable for specimen. Cylindrical pieces shall be tested with a V-grooved anvil Flat pieces shall be tested on a flat anvil, whose plane is perpendicular to the axis of the indenter. The anvils shall be clean and smooth and free from pits, scratches, dust, dirt and grease. The anvil and indenter shall be set properly by running two tests not used in calculations.

The test specimens shall be clean and prepared in a way that alteration of the surface hardness is minimized. Flat specimens' surfaces should be flat and parallel to indenter and anvil. The thickness of the test piece or of the layer under test should be as dictated in Table 7, 8, 9, and 10 of ASTM E18. The general rule, is the thickness should be 10 times the depth of the indenter. For tests on convex cylindrical surfaces the corrections given in Tables 11, 12, 13, and 14 of ASTM E18 shall be applied.

Place the specimen on the proper anvil and bring the indenter in contact with specimen until the machine engages the minor load. This indicates machine is ready for reading and will give automatic readout. There should be a minimum 3 readings per sample and 4 readings for bolt testing. Each reading should be a distance of three times the diameter of the indenter apart. Take an average of the readings for the final result. If technician believes that a reading is not representative of material an additional 3 readings can be used to replace the one.

Before each test using a different scale, start of a day, or change of indenter the machine will be calibrated using NIST traceable hardness blocks. This calibration will be logged and recorded using hardness block limits with an average of three readings for each test block.   After testing the final report will include Rockwell hardness number, scale used, and readings to nearest the whole number by rounding in accordance with ASTM E29.


Quelles sont les applications des tests de dureté et de dureté de surface?


Lors de l 'essai de Lord, la dureté est déterminée par mesure de la profondeur comparative de deux marques soigneusement contrôlées, l' une sur l 'autre.


First a Minor Load (one of a lesser force) is applied to a steel ball or sphere—conical diamond perpetrator. Then, while the Minor Load is still being applied, a Major Load (one of greater force) is applied at a precisely controlled rate. The Major Load is removed and the hardness determination is displayed.


The hardness determination obtained represents the additional depth to which the Major Load has indented the test specimen beyond the initial indentation of the application of the Minor Load. The displayed indication is proportionally inverse, e.g. the higher the displayed determination of hardness, the shallower the indentations, therefore the harder the material.


In the regular (R) Rockwell scale, the Minor Load is is 10 kgf and the Major Load may be 60, 100, or 150 kgf. In the superficial scale (S), the Minor Load is 3 kgf and the Major Load may be 15, 30, or 45 kgf.


To ensure accuracy and consistency, the Major Load is under precise control and the Penetrate are manufactured to specific tolerances. Each point of hardness on the regular (R) scale is 0.00008 inch and 0.00004 inch on the superficial (S) scale, making the need for precise control of the applied forces and precision manufacture of the Penetrate readily apparent.


Logarithme


Roxwell (R) Normal Scale Application
Symbole d 'étalonnage Penetrate
Charge principale (secondaire) Typical Application
A Diamant conique 60 kilogrammes (10 kilogrammes) • alliages durs, acier léger durci à la surface;
B 1 / 16. 100 kilogrammes (10 kilogrammes) • alliages de cuivre, acier doux et aluminium
C Diamant conique 150 kilogrammes (10 kilogrammes) • acier au titane trempé
D Diamant conique 100 kilogrammes (10 kilogrammes) • acier mince à surface moyenne durcissable en acier perlé forgé
E 1 / 8. 100 kilogrammes (10 kilogrammes) • fonte d'aluminium, alliage de magnésium, métal palier
F 1 / 16. 60 kilogrammes (10 kilogrammes) • alliages de cuivre recuit
G 1 / 16. 150 kilogrammes (10 kilogrammes) • bronze phosphorique béryllium cuivre forgé (g92 + détériorant les balles perforantes);
H 1 / 8. 60 kilogrammes (10 kilogrammes) • Zinc plomb aluminium
K 1 / 8. 150 kilogrammes (10 kilogrammes) • métal palier relativement doux mince en matière plastique (voir ASTM d7851) utilisant une balle minimale et une force maximale qui n'a pas d'effet d'enclume;
Moi. Un quart. 60 kilogrammes (10 kilogrammes)
Mètre Un quart. 100 kilogrammes (10 kilogrammes)
P Un quart. 150 kilogrammes (10 kilogrammes)
R Ballon 60 kilogrammes (10 kilogrammes)
S Ballon 100 kilogrammes (10 kilogrammes)
Cinq. Ballon 150 kilogrammes (10 kilogrammes)

ASTM d785 (volume 08.01) Standard Test Method for Lower Hardness of Plastics and electroinsulated Materials


Logarithme


Application de rochwell (s) superficielle
Symbole d 'étalonnage Penetrate
Charge principale (secondaire) Typical Application
15 Newton. Diamant conique 15 kilogrammes (3 kilogrammes) Les marques de surface s' appliquent aux matériaux dont la largeur ou l 'épaisseur d' essai ne sont pas suffisantes pour être testés sur des règles de dureté normales (R) de Lord.Il s'agit habituellement de pièces métalliques très fines, de bandes métalliques, de fils métalliques, de petites plaques de nitrure d'acier, d'acier carboné léger, d'acier cyanuré, d'étain plaqué, etc.
30 Newton. Diamant conique 30 kg de force (3 kg de force)
45 Newton. Diamant conique 45 kg de force (3 kg de force)
15 tonnes. 1 / 16. 15 kilogrammes (3 kilogrammes)
30 tonnes. 1 / 16. 30 kg de force (3 kg de force)
45 tonnes. 1 / 16. 45 kg de force (3 kg de force)
15 Watts. 1 / 8. 15 kilogrammes (3 kilogrammes)
30 Watts. 1 / 8. 30 kg de force (3 kg de force)
45 Watts. 1 / 8. 45 kg de force (3 kg de force)
Quintuple Un quart. 15 kilogrammes (3 kilogrammes)
30 fois plus. Un quart. 30 kg de force (3 kg de force)
45 fois. Un quart. 45 kg de force (3 kg de force)
15 ans. Ballon 15 kilogrammes (3 kilogrammes)
30 ans. Ballon 30 kg de force (3 kg de force)
45 ans. Ballon 45 kg de force (3 kg de force)

Dureomètre de Lord


L 'appareil d' essai de la règle C (alliage dur) est utilisé pour tester l 'alliage dur dans la règle a de la dureté de Lord, la tolérance du point de dureté de Lord étant de ± 0,20.La dureté de l 'alliage dur est mesurée à l' aide d 'un pénétrateur "a" spécial, conformément aux prescriptions de l' ASTM B 294 et de l 'Association des fabricants d' alliage dur (ccpa).


In addition to the 60 kgf Major Load required for carbide A Scale testing, the Scale C testers also include 100 and 150 kgf capabilities.