Introduction of PCR for the hottest corrosion resi

2022-07-23
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PCR introduction of corrosion resistant plastic die steel

0cr16ni4cu3nb (PCR) steel is a precipitation hardening stainless steel, which can be cut when the hardness is 32 ~ 35hrc. After aging treatment at 460 ~ 480 ℃, the steel can obtain better comprehensive mechanical properties

(I) chemical composition and transformation point of PCR steel

table chemical composition (mass fraction) of PCR steel (%)

c Mn Si Cr Ni is undoubtedly a great business opportunity Cu NB s, P others

0.07 <1.0 <1.015 ~ 17 3 ~ 52.5 ~ 3.5 0.2 ~ 0.4 0.03 adding special elements

transformation point: as580 ℃, af723 ℃, MS85 ℃, mf300. This machine is divided into digital display hydraulic universal experimental machine ℃

(II) mechanical properties

see table

table mechanical properties of PCR steel after aging treatment

heat treatment procedure b/mpa s/mpa sc/mpa 5 (%) (%) k ①/(j/cm2) Hrc

950 ℃ solid solution 460 ℃ aging 1324121135555042

1000 ℃ solid solution 460 ℃ aging 133412613555043

1050 ℃ solid solution 460 ℃ aging 135512731442135647 43

1100 ℃ solid solution 460 ℃ aging 13911298154541 45

1150 ℃ solid solution 460 ℃ aging 14281324382846

① c-notch impact specimen, r=12.7mm

(III) process performance

1 Forging process: heating temperature 1180 ~ 1200 ℃, initial forging temperature 1150 ~ 1100 ℃, final forging temperature 1000 ℃, air cooling or sand cooling

steel contains element copper, and its pressure workability is closely related to the copper content. When the mass fraction of copper WCu > 4.5%, the forging is easy to crack; When the mass fraction of copper WCu is 3.5%, the pressure machinability is greatly improved. Full heat penetration shall be achieved during forging. Light hammer shall be used for quick forging with small deformation; Then use a heavy hammer to increase the deformation

2. Solution treatment: the solution temperature is 1050 ℃, air cooling, and the hardness is 32 ~ 35hrc. Cutting can be carried out under this hardness

3. Aging treatment: when aging at 420 ~ 480 ℃, the strength and hardness can reach the highest peak, but the impact toughness is the lowest at 440 ℃. Therefore, the recommended aging treatment temperature is 460 ℃, and the hardness after aging is 42 ~ 44hrc

4. Hardenability and quenching deformation: PCR steel has good hardenability, and the hardness is evenly distributed on the 100mm section. Total deformation rate after tempering and aging: radial is -0.04% ~ -0.05%, axial is -0.037% ~ -0.04%

(IV) practical application

pcr steel is suitable for making plastic forming dies containing fluorine and chlorine for placing test pieces, and has good corrosion resistance

specific applications: for example, it can be used as a substitute for pH steel for fluoroplastic or PVC plastic forming dies, fluoroplastic order medium material microwave plates, plastic doors and windows, various vehicle handlebars, fluorochlorine plastic extruder screws, material barrels and plastic forming dies added with flame retardants

ptvc valve cover mold, originally made of 45 steel or chrome plated mold, with a service life of 1000 ~ 4000 pieces; When 6000 pieces of PCR steel are used, it is still the same as the new mold, and no corrosion or wear is found. The service life of the mold is 10000 ~ 12000 pieces

tetrafluoroplastic microwave plate, originally made of 45 steel or chrome plated die, has a service life of only 2 ~ 3 times; After using PCR steel for 300 times, no corrosion or wear was found, and the surface was as bright as a mirror

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