1.4034 Stainless Steel Bar | X46Cr13 | AISI 420C | 40X13 | SHUNFU METAL

X46Cr13 (1.4034) Stainless Steel — The Highest-Carbon Cr13 Martensitic Grade

X46Cr13 represents the highest carbon variant in the basic Cr13 martensitic stainless steel family, sitting above X30Cr13 (1.4028) and X39Cr13 (1.4031) in both carbon content and hardenability. Through austenitizing at 950–1,050°C followed by oil or forced-air quenching, the 0.43–0.50% carbon content drives formation of a high-carbon martensite structure that — after tempering at 200–350°C — delivers 49–55 HRC hardness on thin sections, with the standard QT800 temper (650–700°C) producing an excellent combination of Rp0.2 ≥ 650 MPa and 800–1,000 MPa tensile strength in sections up to 160 mm. The grade’s 12.5–14.5% chromium delivers a PREN of 12.5–14.5, providing good corrosion resistance in non-chloride media, weak organic acids, steam, and mildly alkaline environments typical of many petroleum-processing streams. SHUNFU METAL refines each 1.4034 heat through AOD processing with ladle-furnace finishing to control carbon within a narrow 0.45–0.48% target for consistent through-section hardenability, and applies LF desulfurization to achieve sulfur levels ≤ 0.008% for improved transverse ductility and fatigue performance in rotating shaft applications. The ISO 9001 framework governs raw-material verification, cast-level spectrometric chemistry checks, heat-treatment chart recording, mechanical test sampling per ASTM A370 / EN ISO 6892-1, and ultrasonic inspection per ASTM E2375. API Q1 supplementaries — independent witness testing, five-year retained reference samples, and complete lot traceability — are applied as standard for all oil and gas industry shipments.

Compared to 440C, 1.4034 offers significantly better toughness (KV ≥ 12 J vs ~2–5 J at equivalent section) and far better machinability in the annealed condition (HB ≤ 245 vs ≤ 269) while sacrificing approximately 5–7 HRC points in peak attainable hardness. This makes X46Cr13 the preferred choice for dynamic components — pump shafts, compressor blades, and valve stems — that demand a practical balance of surface wear resistance, through-section strength, and impact toughness rather than the extreme hardness of 440C. The grade also achieves superior polishability: high-gloss mirror finishing is routinely attainable on quenched-and-tempered surfaces, making it the default martensitic stainless for polished shaft surfaces, gauging surfaces, and hygienic equipment components in food and pharmaceutical auxiliary services within petroleum facilities. SHUNFU METAL supplies X46Cr13 bars in the annealed condition for customer machining with subsequent in-house heat treatment, or fully quenched and tempered to QT800 specifications with EN 10204 3.1 certification.

Equivalent Grades of 1.4034 Across International Standards

The 1.4034 / X46Cr13 chemistry is recognized under numerous national and international standards. SHUNFU METAL maintains dual-certified inventory traceable to ASTM, EN, DIN, JIS, GOST, GB, ISO, BS, and AFNOR norms simultaneously. The ISO 9001 / API Q1 document package ensures seamless acceptance across European, North American, Asian, and Russian-standard end-user regimes.

Note: ASTM 420 (S42000) and JIS SUS420J2 are the nearest equivalents and share the same Cr13 family chemistry. Carbon ranges vary slightly: EN 1.4034 specifies C 0.43–0.50, ASTM 420 specifies C ≥ 0.15 (no upper limit in A276 — 420 covers the full range up to higher-carbon heats), GB 3Cr13 C 0.26–0.35 (slightly lower than 1.4034). GOST 40Х13 specifies C 0.35–0.44 with Cr 12–14 — slightly lower carbon and chromium than EN 1.4034. SHUNFU METAL certifies to the tighter EN 1.4034 ranges as primary standard; ASTM 420 and GOST 40Х13 dual certification is available upon request.

Oil & Gas Industry Applications

1.4034 / X46Cr13 stainless steel bars serve across the petroleum value chain in applications that require a practical balance of surface hardness, through-section strength, and dynamic toughness — filling the gap between softer 410/420 grades and the ultra-hard but lower-toughness 440 series. Its high-carbon martensitic structure, polished surface finish, and moderate corrosion resistance make it the workhorse material for rotating shafts, valve stems, and compressor internals in both upstream and downstream service. SHUNFU METAL supplies 1.4034 bars to API 6D valve manufacturers, pump OEM shops, compressor rebuild facilities, and machining workshops across the global petroleum equipment supply chain, with ISO 9001 and API Q1 certification ensuring full compliance with end-user quality and traceability requirements.

Supply Range of 1.4034 / X46Cr13 Stainless Steel Bar

SHUNFU METAL supplies 1.4034 / X46Cr13 in hot-rolled, forged, and cold-finished bar forms for valve, pump, compressor, and general mechanical engineering manufacturers. Hot-rolled round bars from continuous-cast billet are produced with controlled reduction ratios ≥ 4:1 to ensure sound center condition and uniform structure. Forged bars utilize open-die press forging with upset ratios ≥ 3:1 for full consolidation in heavy sections up to 800 mm. Cold-finished bars are centerless-ground or peeled to IT 7–8 tolerances with surface roughness Ra ≤ 1.6 μm. Every production lot undergoes ultrasonic inspection per ASTM E2375 / EN 10228-3 Class B, dimensional verification, and hardness testing per applicable standard. Under ISO 9001 and API Q1, each bar carries heat-number hard-stamping and full traceability with EN 10204 3.1 certification linking delivered product to cast chemistry, heat-treatment records, and mechanical test results.

Bars supplied in the annealed condition (HB ≤ 245 per EN 10088-3) for customer machining with in-house hardening, or fully quenched and tempered to QT800 specification (Rp0.2 ≥ 650 MPa, Rm 800–1,000 MPa). For high-hardness applications, low-temperature tempering (200–350°C) delivers 49–55 HRC on sections up to 30 mm. Non-standard diameters, stepped shafts, and cut-to-length pieces on inquiry. Forging ring products (OD 200–1,500 mm) available from plate and billet. PKO/PE anti-rust coating, VCI wrapping, and sea-worthy timber crate packing standard for export. Custom packaging and batch-level third-party inspection by SGS, TÜV, or Bureau Veritas on request.

Chemical Composition of 1.4034 X46Cr13 (EN 10088-3 / ASTM A276)

The chemical composition of 1.4034 is defined under both European and North American standards. EN 10088-3 specifies X46Cr13 (1.4034) with C 0.43–0.50%, while ASTM A276/A240 covers this grade under its broad Type 420 (UNS S42000) designation, which encompasses the full 0.15%+ carbon spectrum of the 420 family. For demanding rotating-shaft and fatigue-critical applications, SHUNFU METAL targets a controlled carbon window of 0.45–0.48% to maximize hardenability uniformity while minimizing the risk of quench cracking in heavy sections. The AOD refining practice produces P ≤ 0.025% and S ≤ 0.008% as routine in-house benchmarks, well inside the 0.040% and 0.015% specification maxima. Spectrometric verification on every cast and product analysis on every shipment lot ensure consistent conformance. GB/T 1220 3Cr13 (C 0.26–0.35, Cr 12.0–14.0) is the nearest Chinese specification with slightly lower carbon; GOST 5632 40Х13 (C 0.35–0.44, Cr 12.0–14.0) is the Russian equivalent with marginally lower carbon and chromium than EN 1.4034 — both available dual-certified upon request alongside the primary EN certificate.

Mechanical Properties — Annealed & Hardened / Tempered Conditions

1.4034 / X46Cr13 develops its mechanical properties through two principal heat treatment routes: the standard QT800 route producing a high-strength, high-toughness condition for dynamic components; and a low-temperature temper route for maximum hardness and wear resistance on thinner sections. The standard QT800 treatment — austenitize at 950–1,050°C, oil or forced-air quench, and temper at 650–700°C — delivers an excellent combination of tensile strength (800–1,000 MPa), yield strength (Rp0.2 ≥ 650 MPa), and impact toughness (KV ≥ 12 J longitudinal) in sections up to 160 mm, making it the default heat-treat condition for pump shafts, valve stems, and compressor components. For applications requiring maximum surface hardness, austenitizing at the upper end (1,000–1,050°C) followed by oil quenching and tempering at 200–350°C produces 49–55 HRC on sections up to approximately 30 mm — approaching blade-grade hardness while retaining acceptable toughness for static wear components. Temperatures in the 370–540°C range must be avoided to prevent chromium carbide precipitation and associated loss of corrosion resistance. Annealed bars (750–850°C, furnace or air cool, HB ≤ 245) provide maximum machinability and formability for customer processing — approximately 30–40% better machinability than 440C in the annealed condition, reflecting the lower carbide volume of the 12.5–14.5% Cr composition. SHUNFU METAL executes all heat treatment in calibrated furnaces under ISO 9001 and API Q1 protocols with chart-recorder validation, ensuring repeatable properties across all section sizes and product forms.