T7

Description

T7(A)高韧性碳素工具钢,冷作模具钢。该钢韧性较好,切屑加工性好,价格低廉,来源容易。

T7 is a high toughness carbon tool steel, cold working die steel. The steel has good toughness, good chip machinability, low price and easy source.

Worldwide equivalents of grade T7

country / regionChinaEUGermanyJapanFranceItaly
StandardGBENDIN,WNrJISAFNORUNI
GradeT7C70U (1.1520)1.1620C70W2 SK6SK7  C70E2UC70KU
country / regionPolandCzechiaAustriaRussiaInter 
StandardPNCSNONORMGOSTISO 
GradeN719132K970U7C70U 
Chemical Composition of Cr12 Steel Material
 CSiMnSP
%0.65-0.74%0.35%MAX0.40 %MAX0.03%MAX0.035%MAX

Features

淬透性、耐磨性偏低,淬火时型腔收缩趋势较弱,淬火变形较大,回火稳定性差,淬硬深度为水淬15-18mm,油淬5-7mm。适合于制作易淬断的小件,大件因硬化层浅薄,易发生弧形裂纹。

The hardenability and wear resistance are low, the cavity shrinkage trend is weak during quenching, the quenching deformation is large, and the tempering stability is poor. The quenching depth is 15-18mm for water quenching and 5-7mm for oil quenching.

It is suitable for making small parts that are easy to be quenched and broken. Large parts are prone to arc cracks due to the shallow hardening layer.

Physical properties of T7 steel

Critical temperature of T7 steel

Critical pointAc1Ac3Ar1
Temperature/℃730770700

Expansion coefficient of T7 steel

Temperature/℃20~10020~20020~30020~400
Expansion coefficient/℃-111.8×10-612.6×10-613.3×10-614.0×10-6

Thermal conductivity of T7 steel

Temperature/℃20100300
Coefficient of thermal conductivity,λ/W·(m·K)-144.044.041.9

Heat treatment specification:

正火规范

温度800-820℃,出炉空冷,硬度229-285HBS

Normalizing norms

Temperature 800-820℃, air cooling after being out of the furnace, hardness :229-285HBS.

普通退火规范

(740-750)℃×(2-4)h,以<30℃/h的冷速,缓慢炉冷到温度500-600℃,出炉以后空冷。

Normal annealing specification

(740-750)°C×(2-4)h, with a cooling rate of <30°C/h, slowly cool the furnace to a temperature of 500-600°C, and air-cool after being out of the furnace.

等温球化退火规范

1、(740-750)℃×(2-4)h,(650-680)℃×(4-6)h,后炉冷到500-600℃,出炉空冷,硬度≤187HBS。

2、(750-770)℃×(1-2)h,(680-700)℃×(2-3)h,后炉冷到500-600℃,出炉空冷,硬度163-187HBS。

Specification for isothermal spheroidizing annealing

1. (740-750)℃×(2-4)h, (650-680)℃×(4-6)h, then furnace-cooled to 500-600℃, air-cooling out of the furnace, hardness ≤187HBS.

2. (750-770)℃×(1-2)h, (680-700)℃×(2-3)h, then furnace-cooled to 500-600℃, air-cooling out of the furnace, hardness 163-187HBS.

淬火、回火规范

淬火温度730-760℃,水冷、水油双液冷却或碱浴冷却,淬火硬度57HRC。回火温度160-180℃。

Quenching and tempering specifications

Quenching temperature is 730-760℃, water cooling, water-oil double liquid cooling or alkaline bath cooling, quenching hardness 57HRC. The tempering temperature is 160-180℃.

Available Size

Round BarDiameter(mm): 6-800mm ,Length: 1000-9000mm or custom size
Plate/Flat/BlockThickness: 6mm-500mm , Width: 20mm-1000mm or custom size
Tolerance±1%,Thickness: +/-0.02mm, Width:+/-2mm

T7 Steel Application

1、尺寸小、形状简单、轻负荷的冷作模具,例如小冲头;

2、剪切钢板的剪刀;

3、适于制造要求硬化层不深并保持高韧性的冷作模等;

4、六角螺母冷镦模T7A,推荐硬度48-52HRC;

5、适用于各种中小批量生产的模具;

6、抗冲击载荷的模具。

1、Cold working die with small size, simple shape and light load, such as small punches;

2. Scissors for cutting steel plate;

3. It is suitable for manufacturing Cold working die that require a low hardened layer and maintain high toughness;

4. Hexagon nut cold heading die t7a, recommended hardness 48-52hrc;

5. Suitable for all kinds of small and medium-sized batch production molds;

6. Impact load resistant die.

Description

Tool steels ar a sort of carbon and alloy steels that are used for tool producing applications. they need resistance to abrasion and deformation at elevated temperatures, distinct hardness, and a capability to carry a leading edge.

AISI T7 alloy steel acquires high strength, toughness and also the ability to resist vibration and shock once quenched and tempered.

The data below can offer a summary of grade T7 tool steels.

Equivalent Grade

Chemical Composition

Steel GradeC %Si (≤)Mn (≤)P (≤)S (≤)V (≤)Cr (≤)Ni (≤)Cu (≤)Mo (≤)W (≤)
T70.65 – 0.740.350.400.0350.0300.020.250.200.250.200.30

Mechanical Properties

Mechanical Properties

The mechanical properties of T7 tool steels ar displayed within the following table

PropertiesMetricImperial
Tensile strength650-880 MPa94274 -127663psi
Yield strength350-550 MPa50763-79770
Young�s modulus200000 MPa29007.5 ksi
Elongation at break8-25%8-25%
Proof strengthRp0.2 (MPa)117 (≥)
Tensile strengthRm (MPa)955 (≥)
Impact energyKV (J)33
Elongation at fractureA (%)44
Reduction in cross section on fractureZ (%)21
As-Heat-Treated Condition_Solution and Aging, Annealing, Ausaging, Q+T,etc
Brinell hardness (HBW)_443

Physical Properties

Physical Properties

The Bellowing table shows the physical properties of T7 tool steels

PropertiesMetricImperial
Density7.7 g/cm30.278 lb/in3
Melting point1450 � 1510�C2642 � 2750�F

Heat Treatment Specification

Shapes and dimensions

Delivery Condition

Product typeProductsDimensionProcessesDelivery Status
Plates / SheetsPlates / Sheets0.08-200mm(T)*W*LForging, hot rolling and cold rollingAnnealed, Solution and Aging, Q+T, ACID-WASHED, Shot Blasting
Steel BarRound Bar, Flat Bar, Square BarΦ8-1200mm*LForging, hot rolling and cold rolling, CastBlack, Rough Turning, Shot Blasting,
Coil / StripSteel Coil /Steel Strip0.03-16.0x1200mmCold-Rolled & Hot-RolledAnnealed, Solution and Aging, Q+T, ACID-WASHED, Shot Blasting
Pipes / TubesSeamless Pipes/Tubes, Welded Pipes/TubesOD:6-219mm x WT:0.5-20.0mmHot extrusion, Cold Drawn, WeldedAnnealed, Solution and Aging, Q+T, ACID-WASHED

Applications

T7 tool steel is used for making various tools that withstand impact, vibration load, good toughness, medium hardness and low cutting capacity, such as small size pneumatic tools, chisel and saw for woodworking, stamping, forging die, and fitter tools (hammer head), lathe thimble, drill bit, scissors, etc.

The following ar the list of applications of T7 tool steels:

Chisels, tiny gas tools, shaping die, Rivets, Carpenter saws and Metal scissors.