Pin, Shaft, Bushing

调质钢是指含碳量约 0.3–0.6% 的中碳钢或低合金钢，通过淬火+高温回火（500–650℃）形成回火索氏体组织，以获得强度、塑性和韧性的良好配合。常见牌号包括 45、40Cr、42CrMo、35CrMo、40CrNiMo 等。

调质钢由于碳含量较高，不适合再做渗碳处理，但非常适合采用感应淬火来提升表层硬度和耐磨性，同时保持心部韧性。 45钢、40Cr、42CrMo 等常见调质钢，广泛用于齿轮、轴类零件的感应淬火工艺。

42CrMo调质后使用，调质后硬度285-340HB 或者 28-35HRC；还可选择进行表面感应淬火，以提高其耐磨性，调质后中频感应淬火，表面硬度55-60HRC；不能采用渗碳处理，因为其含碳已经很高（中碳钢），容易引起开裂。42CrMo可以采用氮碳共渗氧化，也称为软氮化+后氧化复合处理（Oxy Nitrocarburizing）

42CrMo国外相似性能的调质钢

42CrMo4 EN10083-3

ASTM AISI 4140Plain Bearing

澳大利亚轴类零件原材料 AS1444-X9940V（EN26, BS970: PART 3: 1991 826M40 ） High tensile steel

进过研究标准，42CrMo GB3077 为其国内替换材料，制造工艺，调质+表面高频感应淬火

EN26 is a 2.5% nickel - chromium - molybdenum high hardenability, high tensile steel, generally supplied hardened and tempered in the tensile range 1000 - 1150 Mpa (Condition V) Rc 31 - 38.Characterised by high strength and toughness in very large sections - similar to EN25 but with higher carbon content, particularly suitable where high surface pressure exists.

Pre hardened and tempered EN26 can be further surface hardened by flame or induction hardening, and by nitriding.

EN26 is used extensively in most industry sectors for applications requiring higher tensile and yield strength than 4140, 4340 or EN25 can provide.

Typical uses are: Axles, Connecting Rods, Die Holders, Hydraulic Shafts, Spindles, Motor Shafts, Pins, Rams, Rolls, Sockets, Tool Holders, Torsion Bars etc..

EN26 hardened and tempered bar can be further surface hardened by either the flame or induction hardening methods resulting in a case hardness in excess of Rc 50.

EN26 High Tensile Steel | Interlloy | Engineering Steels + Alloys

AS1444-4140 (No letter)
AS1444-4140T (d≤100mm)
AS1444-4140S (d≤150mm)

42CrMo GB3077 为其国内替换材料，制造工艺，调质+表面高频感应淬火

4140 is a 1% chromium - molybdenum medium hardenability general purpose high tensile steel - generally supplied hardened and tempered in the tensile range of 850 - 1000 Mpa (condition T).4140 is now available with improved machinability, which greatly increases feeds and/or speeds, while also extending tool life without adversley affecting mechanical properties.

Pre hardened and tempered 4140 can be further surface hardened by flame or induction hardening and by nitriding.

4140 is used extensively in most industry sectors for a wide range of applications such as:
Adapters, Arbors, Axle Shafts, Bolts, Crankshafts, Connection Rods, Chuck Bodies, Collets, Conveyor Pins & Rolls, Ejector Pins, Forks, Gears, Guide Rods, Hydraulic Shafts & Parts,Lathe Spindles, Logging Parts, Milling Spindles, Motor Shafts, Nuts, Pinch Bars, Pins Various, Pinions, Pump Shafts, Rams, Sockets, Spindles, Sprockets, Studs, Tool Holders, Torsion Bars, Worms etc..

4140 High Tensile Steel | Interlloy | Engineering Steels + Alloys

表面感应淬火Induction hardening

感应淬火是一个可以在不影响心部组织的情况下生成表面硬化层从而提高耐磨性、表面硬度及疲劳寿命的表面硬化工艺，可加强局部区域的强度、抗疲劳及耐磨性能。感应淬火可生成一层硬化层较深、硬度较高的表层，可承受极高的重荷。在柔软的心部之外有一层极其坚硬的外层，因此可提高物体的整体疲劳强度。这些特性对于要承受扭转载荷的零部件、以及要承受冲击力的表面来说，都是梦寐以求的。

Induction hardening process used to increase wear resistance, surface hardness and fatigue life through creation of a hardened surface layer while maintaining an unaffected core microstructure.

The primary benefits are improvements in strength, fatigue and wear resistance in a localised area without having to redesign the component.

Induction imparts a high surface hardness with a deep case capable of handling extremely high loads. Fatigue strength is increased by the development of a soft core surrounded by an extremely tough outer layer. These properties are desirable for parts that experience torsional loading and surfaces that experience impact forces.

渗氮Nitriding

渗氮是一种向金属表面渗入氮原子的化学热处理工艺。所采用的渗氮介质是气体，一般是氨气。因为氨气容易在金属表面受热裂解产生氢气和氮气，在这个裂解的过程中会有微量的活性氮原子产生。这些活性氮原子被金属原子捕捉产生氮化物或者扩散到金属内部，这个过程就是渗氮。渗氮工艺使得金属表面产生氮原子的固溶强化以及氮化物的弥散强化，从而获得很高的硬度以及耐磨性。致密的氮化物层也会产生在金属表面，它的硬度更高，并且具有很高的耐酸碱腐蚀性，在金相腐蚀下也保持白亮色，因此也被称为“白亮层”。

气体氮化还可以继续细分为“硬氮化”和“软氮化”。“硬氮化”指的是只采用氨气作为渗氮介质，只有氮原子渗入的氮化工艺。“软氮化”指的是采用多种渗氮介质，既有氮原子又有碳原子渗入的氮化工艺。“软氮化”的真正学名应为“氮碳共渗”（Nitro-carburizing），意指在渗氮的同时进行渗碳的过程。渗氮过程中需要将钢材再加热，需注意这个温度不能超过前道工序（比如调质）的回火温度，否则会引起二次回火，导致芯部的硬度及力学性能的改变。

它与另一重要的化学热处理工艺—碳氮共渗（Carbo-nitriding）只有一字之别，应注意区分。氮碳共渗是以渗氮为主，渗碳为辅。而碳氮共渗是以渗碳为主，渗氮为辅。气体氮化的应用十分广泛，几乎所有金属都可以对其进行表面氮化处理。以碳钢为例，从低碳的纯铁以及易切削钢，到中碳的合金钢，再到高碳的高速钢，都有渗氮的应用。

NITRIDING / NITROCARBURIZING

Perfect for components that are subject to heavy loading, controlled nitriding/nitrocarburizing imparts a high surface hardness which results in a higher resistance to wear, scuffing, galling, seizure, and corrosion. Controlled nitriding/nitrocarburizing allows the adjustment of different case properties, making it adaptable for a broader range of applications. A low-temperature process, nitriding/nitrocarburizing minimizes distortion of the finished parts.

氮碳共渗氧化OXYNITRIDING / OXYNITROCARBURIZING ONC

也称为“软氮化+后氧化复合处理”。尼萃斯Nitrex称之为：ONC® - 渗氮过程后处理/氮碳共渗氧化

鲍迪克Bodycote称之为：Corr-I-Dur®

当主要要求耐大气腐蚀性及新颖黑色抛光时，这是适宜的工艺。其目标是将通过渗氮获得的白层的最顶端部分转变为一个复杂的尖晶石型结构（主要由氧化铁的Fe3O4类型组成）。

此类渗氮后氧化处理具有提高已经氮化组分的耐腐蚀性的效能。可提高钢的耐腐蚀性，耐磨损性，抗疲劳载荷性，同时赋予表面颇具吸引力的深色或黑色外观。在氧化过程无污染的化学试剂加入，较其他化学处理更环保。

In-process post-nitriding/nitrocarburizing oxidation. When resistance to atmospheric corrosion and an attractive black finish are the main requirements, ONC is the best technology.

Oxynitriding/oxynitrocarburizing transforms the very top portion of the white layer obtained with Nitriding technologies into a complex spinel type structure consisting mostly of Fe3O4 type of iron oxide. As a result, the post-nitriding oxidation treatment has a net effect of enhancing the corrosion resistance of an already nitrided component, simultaneously enhances corrosion and wear resistance of steel, while giving the surface an attractive dark or black appearance, expressly desired by many customers.

常用制造工艺

42CrMo常规的工艺路线

圆钢锯料/锻件毛坯——粗车——UT/MT探伤——调质处理（抗拉1080Mpa）——半精车——MT探伤——感应淬火——粗磨——MT探伤——镀铬——精磨

42CrMo渗氮工艺路线

锻件——粗车——调质处理——半精加工——氮化前除应力——精加工——氮化处理（非氮化部分保护）——精磨

热处理后，外形尺寸有些许增大

42CrMo国外相似性能的调质钢

表面感应淬火Induction hardening

渗氮Nitriding

氮碳共渗氧化OXYNITRIDING / OXYNITROCARBURIZING ONC

常用制造工艺

Failure Analysis

相关材料标准