【突发】中国C919客机交付目标大幅下调三分之二，...

[helloworld77]

【突发】中国C919客机交付目标大幅下调三分之二，... https://v.douyin.com/0PsWuHa2CQI/ 10/30 dAG:/ m@d.nD

[helloworld77]

1.56 复制打开抖音，看看【政经不分家的作品】外媒报道:今年C919交付量大幅不及预期！# 彭博... https://v.douyin.com/wbQKFSfkpi8/ 10/26 Slp:/ L@j.Pk

[helloworld77]

0.02 复制打开抖音，看看【航势致行的作品】商飞削减C919交付# 彭博社 # 路透社 # 财... https://v.douyin.com/IAgzDCljAC4/ JiC:/ h@b.AG 10/06

[马大帅]

为啥交付不了？
全国产 工人996也不是事
卡在哪

[zmimy]

为啥交付不了？
全国产 工人996也不是事
卡在哪

核心关键系统必须依赖外国人

[弃婴千枝]

为啥交付不了？
全国产 工人996也不是事
卡在哪

主起落架

美帝限制300M钢供应，用国产40CrMnSiMoVA在法国锻造的时候说会产生偏析，但是由于适航证的考虑又不能搬回国锻造，所以党妈现在考虑919项目整个推翻，全部变成国产在中国生产也不考虑适航证了，反正也不可能给你的

好多圈外人以为是发动机，恰恰发动机不是问题，法国要几台给几台

总之，919现在食之无肉弃之有味，

[kazan]

主起落架

美帝限制300M钢供应，用国产40CrMnSiMoVA在法国锻造的时候说会产生偏析，但是由于适航证的考虑又不能搬回国锻造，所以党妈现在考虑919项目整个推翻，全部变成国产在中国生产也不考虑适航证了，反正也不可能给你的

好多圈外人以为是发动机，恰恰发动机不是问题，法国要几台给几台

总之，919现在食之无肉弃之有味，

尼玛这么悲壮

[Mitaa]

主起落架

美帝限制300M钢供应，用国产40CrMnSiMoVA在法国锻造的时候说会产生偏析，但是由于适航证的考虑又不能搬回国锻造，所以党妈现在考虑919项目整个推翻，全部变成国产在中国生产也不考虑适航证了，反正也不可能给你的

好多圈外人以为是发动机，恰恰发动机不是问题，法国要几台给几台

总之，919现在食之无肉弃之有味，

随便哪项都能卡，还不需要现在就卡发动机
法佬比较艺术，卡住2/3，还留活口

[弃婴千枝]

随便哪项都能卡，还不需要现在就卡发动机
法佬比较艺术，卡住2/3，还留活口

到年底吧

欧空局说今年年底前颁发esa适航证，如果还没颁发我估计十有八九党妈就撂挑子不干了

毕竟波音777级别的运20都飞了这么多年了

[wanmeishijie]

主起落架

美帝限制300M钢供应，用国产40CrMnSiMoVA在法国锻造的时候说会产生偏析，但是由于适航证的考虑又不能搬回国锻造，所以党妈现在考虑919项目整个推翻，全部变成国产在中国生产也不考虑适航证了，反正也不可能给你的

好多圈外人以为是发动机，恰恰发动机不是问题，法国要几台给几台

总之，919现在食之无肉弃之有味，

我早说了，上海人搞不成国产飞机，崇洋媚外！要我们河北人搞，先起个高炉炼钢！

[magagop]

主起落架

美帝限制300M钢供应，用国产40CrMnSiMoVA在法国锻造的时候说会产生偏析，但是由于适航证的考虑又不能搬回国锻造，所以党妈现在考虑919项目整个推翻，全部变成国产在中国生产也不考虑适航证了，反正也不可能给你的

好多圈外人以为是发动机，恰恰发动机不是问题，法国要几台给几台

总之，919现在食之无肉弃之有味，

第一次聽說300M，漲見識了

300M is a low alloy, vacuum melted steel of very high strength and hardenability. Essentially it is a modified AISI 4340 steel with silicon, vanadium, and slightly more carbon and molybdenum. 300M has a very good combination of strength in the 280-305 KSI range (1930–2100 MPa). It is a through hardening alloy with a combination of high toughness, fatigue strength, and good ductility.

Alloy Steel 300M is used in the following application areas:
Aircraft landing gear
High strength bolts
Missile components
Motorsport applications
Driveshafts
Flap tracks
Airframe parts

[tingtingliu]

主起落架

美帝限制300M钢供应，用国产40CrMnSiMoVA在法国锻造的时候说会产生偏析，但是由于适航证的考虑又不能搬回国锻造，所以党妈现在考虑919项目整个推翻，全部变成国产在中国生产也不考虑适航证了，反正也不可能给你的

好多圈外人以为是发动机，恰恰发动机不是问题，法国要几台给几台

总之，919现在食之无肉弃之有味，

说的好像赛峰全部股份都是是斯莱克玛的一样

[弃婴千枝]

看看，driveshaft
你去autozone看看，cv axle只有2个来源---原厂，or 中国，
所以党妈的40CrMnSiMoVA钢产业是巨大无比的

第一次聽說300M，漲見識了

300M is a low alloy, vacuum melted steel of very high strength and hardenability. Essentially it is a modified AISI 4340 steel with silicon, vanadium, and slightly more carbon and molybdenum. 300M has a very good combination of strength in the 280-305 KSI range (1930–2100 MPa). It is a through hardening alloy with a combination of high toughness, fatigue strength, and good ductility.

Alloy Steel 300M is used in the following application areas:
Aircraft landing gear
High strength bolts
Missile components
Motorsport applications
Driveshafts
Flap tracks
Airframe parts

[xiaoju]

金属加工根本不是问题，你弟的钢铁工业早就烂光了

主起落架

美帝限制300M钢供应，用国产40CrMnSiMoVA在法国锻造的时候说会产生偏析，但是由于适航证的考虑又不能搬回国锻造，所以党妈现在考虑919项目整个推翻，全部变成国产在中国生产也不考虑适航证了，反正也不可能给你的

好多圈外人以为是发动机，恰恰发动机不是问题，法国要几台给几台

总之，919现在食之无肉弃之有味，

[magagop]

看看，driveshaft
你去autozone看看，cv axle只有2个来源---原厂，or 中国，
所以党妈的40CrMnSiMoVA钢产业是巨大无比的

鋼鐵學問太深了

Compare 4 steels: 300M, S2, T10, CPM3V

Here’s a concise, practical comparison of the four steels—what they are, how they behave, and when you’d pick each one.

Snapshot: type, hardness window, standout traits & common uses

Steel Type / purpose Typical hardness after HT What it excels at Typical uses

300M (4340M) Ultra-high-strength structural alloy (VAR 4340 + Si/V) HRC _52–55 in 1.9–2.1 GPa (275–305 ksi) condition Very high strength, fracture/fatigue toughness in thick sections Aircraft landing gear, high-load shafts/fasteners, structures
S2 Shock-resisting tool steel (AISI S-series) HRC _60→50 (tempering 350–800 °F) Survives torsional/impact shock; “bends before it breaks” at high HRC Impact driver bits, punches, pins, chisels
T10 (GB/T 1298) Chinese plain-carbon tool steel (₁.0%C; W-series analog) HRC _60–64 when fully hardened High hardness & simple heat-treat; good edge taking; low hot-hardness & hardenability Knives/swords, chisels, small cold-work tools
CPM 3V Powder-metallurgy tool steel (Cr-Mo-V) HRC _58–60 (typical) Extreme toughness with good wear; resists chipping far better than typical cold-work grades Heavy-duty knives, dies, shear blades, impact-prone tools

---

Composition (abridged, by role)

300M ≈ 0.40–0.45%C with elevated Si and V vs 4340; vacuum-remelted (AMS 6417/6419). Built for 270–300 ksi tensile service.

S2 ≈ 0.40–0.55%C, ₁% Si, ₀.4–0.5% Mo, small Mn/V—engineered for shock resistance.

T10 ≈ 1.0%C with small Si/Mn (trace Cr/Ni/Cu limits) per GB/T 1298—a water/low-alloy hardening carbon tool steel; similar family to W-series.

CPM 3V ≈ 0.80%C, Cr ₇.5%, Mo ₁.3%, V ₂.75% (Crucible PM)—fine, clean carbides for toughness + wear.

---

How they differ in practice

Impact/torsion shock:
S2 is purpose-built to survive violent torque spikes; that’s why it dominates impact driver bits and other struck/twisted small tools. 3V can approach S-grade shock toughness while offering more wear resistance, but it’s overkill for cheap bits; 300M isn’t a tool steel and would be tempered down into the same hardness band without giving wear/hot-hardness benefits. T10 is too brittle at comparable hardness for repeated impact.

Edge & wear vs toughness:
T10 gets very hard (60–64 HRC) and takes a keen edge but has low hot-hardness/hardenability—great for small, simple tools or blades with conservative geometry. CPM 3V delivers far higher toughness than typical cold-work steels while keeping good wear; it’s the go-to for “beat-on-it” knives/dies that must not chip.

High-strength structures:
300M wins when you need bulk strength + fatigue life in large sections (landing gear, high-load shafts). It’s not optimized for cutting edges or red-hardness like high-speed/tool steels.

---

When to pick what (rule-of-thumb)

Driver/impact bits, punches/chisels: S2 (shock toughness at practical cost).

Heavy-use knives/dies that must not chip: CPM 3V (PM toughness with useful wear).

Simple, very hard small tools/blades with traditional HT: T10 (cheap, hard; manage quench/geometry carefully).

Aerospace-grade structural parts: 300M (strength/fatigue in thick sections).

[magagop]

金属加工根本不是问题，你弟的钢铁工业早就烂光了

我不這麼認為，至少刀槍工具鋼，美國廠商仍然有一部分市場。

[xiaoju]

你弟炼钢技术连印度都不如，就靠贸易保护活着了

我不這麼認為，至少刀槍工具鋼，美國廠商仍然有一部分市場。