Non-Quenched & Tempered Mechanical Structural Steel Round Bar
Introduction:
Non-quenched & tempered mechanical structural steel round bar is a new energy-saving alloy steel micro-alloyed with V, Nb, Ti, S. After controlled rolling and controlled cooling, uniform ferrite-pearlite or bainite structure can be obtained directly without separate quenching and tempering heat treatment, which greatly shortens processing cycle, reduces energy consumption and avoids workpiece deformation caused by quenching distortion.
Product Overview
Non-quenched & tempered mechanical structural steel round bar is a new energy-saving alloy steel micro-alloyed with V, Nb, Ti, S. After controlled rolling and controlled cooling, uniform ferrite-pearlite or bainite structure can be obtained directly without separate quenching and tempering heat treatment, which greatly shortens processing cycle, reduces energy consumption and avoids workpiece deformation caused by quenching distortion. The diameter range covers ø12–300 mm, including domestic standard grades, foreign imported equivalent grades and factory special customized grades: C70S6BY, 1E1497, 30MnVS6, 38MnVS6, 49MnVS3, F45MnVS, F40MnVS, F45VS, 20MnV6, HY4520, SY740, JGF45MnVS, JGF45V, HL610, HL740, JG45. Delivery states include hot rolled black bar, normalized bar and peeled bright bar. It is widely applied in automobile crankshafts, connecting rods, steering knuckles, axles, engineering machinery heavy-load shafts, fastener forgings and mass-produced mechanical structural parts.
Representative Grades
|
Grade |
Executive Standard |
Core Performance & Application |
|
C70S6BY / 49MnVS3 |
EN 10263 |
European sulfur-manganese-vanadium free-cutting non-quenched steel, high strength, good machinability; crankshafts, heavy-duty connecting rods |
|
30MnVS6 / 38MnVS6 / 20MnV6 |
EN 10263 |
Medium-low carbon V microalloy non-quenched steel, balanced strength & toughness; automobile suspension parts, small shaft forgings |
|
F40MnVS / F45MnVS / F45VS |
GB/T 15712 |
National standard sulfur-vanadium series non-quenched steel, stable ferrite-pearlite; vehicle half shafts, steering knuckles, general gear blanks |
|
1E1497 |
Foreign special automobile grade |
Bainite non-quenched steel, ultra-high fatigue strength; high-speed engine structural forgings |
|
HY4520 / JG45 |
Domestic universal non-quenched steel, low cost |
Medium-strength, for light-load machinery shafts, bolt blanks, stamping forgings |
|
SY740 / HL610 / HL740 |
Factory bainite non-quenched special steel |
High tensile strength, impact resistant; mining machinery, heavy engineering equipment parts |
|
JGF45MnVS / JGF45V |
Mill improved vanadium microalloy grades |
Uniform grain, low fluctuation of mechanical properties, batch stable for auto mass production lines |
Grade Description
-
01
MnVS series (30MnVS6/38MnVS6/F45MnVS): Mn for strength improvement, V for grain refinement, S for free-cutting performance; after hot forging + air cooling, finished mechanical properties can be reached without quenching & tempering.
-
02
C70S6BY / 49MnVS3: European high-strength non-quenched steel, high carbon matching sulfur alloy, for heavy-load automobile power components.
-
03
Bainite grades (1E1497/SY740/HL740): Controlled cooling to form bainite matrix, higher strength and fatigue life than pearlite series, suitable for high-stress working conditions.
-
04
JGF/HY/JG series: Domestic optimized non-quenched steel, stable batch performance, cost advantage for domestic auto and machinery manufacturers.
Product Specifications
|
Item |
Specific Parameters |
|
Product Form |
Hot rolled round bar;Forged round bar;Peeled bright bar |
|
Diameter Range |
ø12 mm – ø300 mm |
|
Standard Length |
3m / 6m / 9m / 12m; customized fixed-length cutting supported |
|
Delivery Condition |
Hot rolled controlled cooling (as rolled) / Normalized / Peeled & ground |
|
Surface Treatment |
Hot rolling oxide scale; shot blasting, peeling & polishing optional |
|
Size Tolerance |
Comply with GB/T702, EN10263 dimensional tolerance standard |
|
Straightness |
Standard grade ≤3mm/m; precision peeled bar ≤1.5mm/m |
|
Metallurgical Feature |
Uniformly distributed V carbonitride precipitates, fine equiaxed grains, low segregation |
Core Advantages
1. Cancel Quenching & Tempering Process, Energy Saving & Cost Reduction: Target mechanical properties are obtained directly after forging air cooling; eliminate heat treatment cost, avoid quenching deformation, reduce reject rate of precision parts.
2. Balanced Strength, Toughness & Machinability: Micro-alloy precipitation strengthening + sulfur free-cutting system, high tensile strength and fatigue resistance while keeping smooth chip breaking during CNC turning and drilling.
3. Stable Batch Mechanical Performance: EAF+LF+VD smelting + precise TMCP controlled rolling & cooling, tiny grain size, small performance fluctuation between heats and batches.
4. Complete Grade System: Cover pearlite low/medium-strength grades and bainite high-strength grades, including domestic, European and factory special brands, to match light, medium and heavy load parts.
5. Low Processing Deformation Risk: No high-temperature quenching, internal residual stress of forgings is low, stable dimensional accuracy after finishing.
6. Wide Size Coverage ø12–300mm: Meet small fastener blanks to large crankshaft, heavy shaft raw material demands, flexible supporting deep processing customization.
Main Application Fields
-
Automobile Power System
Engine crankshafts, connecting rods, camshafts, transmission shafts, piston pins, heavy-duty bolt forgings.
-
Automobile Chassis Parts
Steering knuckles, half shafts, stabilizer bars, suspension control arm forgings, wheel hub shafts.
-
Engineering & Mining Machinery
Heavy load transmission shafts, gear blanks, hydraulic cylinder mandrels, excavator and crane structural forgings.
-
General Mechanical Equipment
Medium-strength shafts, fixture positioning pins, valve body blanks, high-strength standard fasteners.
-
Mass Production Forging Parts
Automatic forging line raw materials, replace 45#, 40Cr to cancel heat treatment and shorten production cycle.
-
Export Auto Parts
C70S6BY, 38MnVS6, 49MnVS3 European standard grades for overseas automobile supporting manufacturers.
Packaging & Services
- 1. Executive Standards: GB/T 15712 Non-quenched and tempered steel for mechanical structural parts, EN 10263; meet factory special technical specifications for HL/JGF/HY series.
- 2. Full Inspection Items: Chemical composition analysis, tensile test, impact test, hardness test, metallographic grain & precipitate inspection, dimensional inspection; optional ultrasonic flaw detection (UT).
- 3. Material Certification: EN10204 MTC 3.1 mill test certificate; SGS, BV third-party factory inspection available.
- 4. Packaging: Steel wire bundled, waterproof plastic film wrapped, end anti-collision caps; support container and bulk vessel shipment.
- 5. MOQ: 1 ton per grade; mixed grades and mixed sizes can be loaded in one container.
- 6. Custom Processing: Fixed-length cutting, surface peeling & grinding, shot blasting rust removal, stress relief normalizing, precision straightening.
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Contact Us
- WhatsApp: +86-185 9567 2991
- Email: martinliu@rongtianmetal.com
- Tel: +86-185 9567 2991
- Address: 8F, Bldg 2, Jinke Zhihui Valley No. 65 Hongyuan Rd., Jinshui Dist. Zhengzhou, China.
