High-strength quenched formed body with good corrosion resistance and process for producing the same

A process for producing a quenched formed body, comprising the following steps performed sequentially:

• preparing a formed-body steel material, on which a zinc-plated layer is coated, wherein the zinc-plated layer contains at least one of Al and Si, which has an alloying-retarding function and a readily-oxidizing function, independently or compositely in an amount of 0.15% by mass or more, wherein the zinc-plated layer contains Fe in an amount of less than 1% by mass and wherein % by mass is based on the total weight of the zinc-plated layer as 100% by mass;
• and
• quenching said formed-body steel material after heating said formed-body steel material to a temperature of from 800° C. to 950° C. in an oxidizing atmosphere comprising oxygen in an amount of 0.1% by volume or more, thereby producing:
• a quenched formed body comprising an after-quenching formed-body steel material having an after-quenching zinc-plated layer disposed on the surface of said after-quenching formed-body steel material,
• wherein the zinc-plated layer has been subjected to the quenching along with said formed-body steel material,
• wherein the after-quenching zinc-plated layer comprises Zn as a major component,
• wherein the after-quenching zinc-plated layer is 30% by mass or less of Fe,
• wherein % by mass is based on the total weight of the after-quenching zinc-plated layer as 100% by mass, and
• wherein the after-quenching zinc-plated layer is present on the after-quenching formed-body steel material in an amount of 30 g/m2 or more.