Spring steel bar 50CrVa

Spring steel 50 crva chemical composition:

Spring steel 50 crva mechanical properties:
Tensile strength of sigma b (MPa) : 1274 (130) or higher yield strength sigma s (MPa) : 1127 (115) or higher
Elongation delta (%) : 10 or higher percentage reduction of area bits (%) : 40 or higher
Hardness: hot rolled, 321 hb or less; Cold drawn + heat treatment, 321 hb or less

50 crva spring steel heat treatment specification and metallographic organization: heat treatment specification: 850 ℃ quenching + 20 ℃, oil cooling; Tempering 500 ℃ + 50 ℃ (special needs, plus or minus 30 ℃).

50 crva representation:

1) steel grade at the beginning of the two figures show that the carbon content of steel, with the average carbon content per few said, such as cr, 40 25 cr2mova alloy pipe

(2) main alloy element in steel, in addition to the individual microalloy element, usually expressed as a percentage. When the average alloy content < 1.5%, generally only mark symbol in the steel grade, and not indicate content, but in special cases, easy to cause confusion, after the element symbol can be labeled with Numbers "1", such as steel grade "12 crmov" and "12 cr1mov", the former chromium content is 0.4 0.6%, which is 0.9-1.2%, all the rest of the ingredients are the same. When the average alloy element content of 1.5% or higher, or 2.5%, 3.5% or more... , behind the symbol should be marked content, can be said for 2, 3, 4... And so on. For example, 18 cr2ni4wa.

(3) of the steel vanadium V, Ti, aluminum, titanium, boron, rare earth and alloy elements such as RE B, micro alloying elements, although the content is very low, still should be in steel grade drawings. 20 MNVB steel, for example. Vanadium is 0.07-0.12%, boron is 0.001-0.005%. (4) advanced high-quality steel should be at the end of the steel grade "A", to distinguish it from high quality steel in general.

(4) advanced high-quality steel should be at the end of the steel grade "A", to distinguish it from high quality steel in general.

(5)Alloy structural steel for special purposes (< http://tegang.mouldu.com/keylist/o1835.html >, as steel grade (or suffix) on behalf of the steel grade USES symbols. Such as riveting screw dedicated 30 crmnsi steels, steel grade is expressed as ML30CrMnSi.

Spring steel 50 crva characteristics and scope of application: the good mechanical properties and process performance, high hardenability, adding vanadium steel grain refinement, reducing heat sensitivity, increase the strength and toughness, high fatigue strength, yield ratio is higher, but poor weldability, cold because of the low deformation plasticity. Is a kind of more advanced spring, as a large section of important spring high load and working temperature < 300 ℃ of the valve spring, piston, spring, the relief valve spring.