When chrome bar/piston rod need Quenched and tempered?

When chrome bar / piston rod need Quenched and tempered ?

Due to the difference in the scope of use and working conditions of the piston rod, sometimes the piston rod must undergo processes such as induction, quenching and tempering, and nitriding. Through these processes, the performance requirements of certain aspects of the piston rod may be more suitable for product applications. However, not all piston rods need to be tempered. The quenching and tempering treatment mainly depends on the material used for the piston rod. Because quenching and tempering is only a dual heat treatment process of quenching and high temperature tempering, the piston rod products after quenching and tempering can obtain the following benefits:

 

1. It can effectively improve the working strength of the material.

 

2. After the piston rod is quenched and tempered, it can have good comprehensive mechanical properties.

 

3. It helps to close the micro cracks on the surface, hinders the expansion of corrosion, and improves the surface corrosion resistance.

 

4. The piston rod is quenched and tempered, which can effectively eliminate the internal stress caused by quenching to obtain the expected mechanical properties.

 

42CrMo4, 40Cr Hard Chrome Plated Bar With Quenched / Tempered For Cylinder

Detailed Product Description

 

1. Material: CK45, ST52, 20MnV6, 42CrMo4, 40Cr

2. Diameter: 6mm - 1000mm

3. Length: 1000mm - 8000mm

4. Tensile strength: Not less than 610 N/MM2

5. ISO9001:2008

 

Detailed Description

1.CHEMICAL COMPOSITION

Material	C%	Mn%	Si%	S%	P%	V%	Cr%
CK45	0.42-0.50	0.50-0.80	0.04	0.035	0.035
ST52	0.22	1.6	0.55	0.035	0.04
20MnV6	0.16-0.22	1.30-1.70	0.10-0.50	0.035	0.035	0.10-0.20
42CrMo4	0.38-0.45	0.60-0.90	0.15-0.40	0.03	0.03		0.90-1.20
40Cr	0.37-0.45	0.50-0.80	0.17-0.37				0.80-1.10

 

2.MECHANCIAL PROPERTIES

Material	T.S  N/MM2	Y.S  N/MM2	E%(MIN)	CHARPY	CONDITION
CK45	610	355	15	>41J	NORMALIZE
CK45	800	630	20	>41J	Q + T
ST52	500	355	22		NORMALIZE
20MnV6	750	590	12	>40J	NORMALIZE
42CrMo4	980	850	14	>47J	Q + T
40Cr	1000	800	10		Q + T

 3. SUPPLY CONDITION

    Ground  and  chrome plated 

4. CHROME THICKNESS

     20 to 30 micron

5. SURFACE ROUGHNESS

     Ra≤0.2 micron and  Rt≤2 micro

6. TOLERANCES ON DIA

    ISO f7 on the diameter

7.OVALITY

Half of the tolerance ISO f7

8. STRAIGHTNESS

   ≤0.2MM/M

9. SURFACE HARDNESS

   850-1150HV (vickers 100g)

10.COHESION

   No cracks,breaking or detaching after thermic shock(warming up at 300 celsius degrees and cooling

   in water)

11 .POROSITY

     Test according to ISO 1456/1458 and result yaluation according to ISO 4540 rating 8-10

12 CORROSION RESISTANCE

     Test in natural salt spray according to ASTM B 117-72hours

     Results evaluation according to ISO 4540 RATING 7-10

13. WELDABILITY 

      Good

14. PACKING

     Anti rust oil to be applied on material and each rod to be packed in paper sleeve

15. CERTIFICATE

     All certificate related with material heat treatment and plating is required